Version: 1.0
Title: Multidimensional Nuclear Magnetic Resonance Peak Fitting and Analysis
Description: Tools for fitting and analyzing 1D-4D nuclear magnetic resonance spectra with analytical models of peak shapes and peak groups. The package reads spectra in 'NMRPipe' format, builds constrained parameter structures for chemical shifts, line widths, scalar couplings, volumes, and phases, and performs nonlinear least-squares optimization for iterative peak discovery or simultaneous fits across multiple spectra. It also provides methods for visualization, preprocessing, and kinetic analysis of 1D time-series data, including automated phase optimization, solvent suppression, time-domain correction for frequency shifts and line broadening, modeling spectra as linear combinations of two component spectra, and exponential rate fitting.
License: GPL-3
URL: https://github.com/smith-group/fitnmr/, https://smith-group.github.io/fitnmr/
Imports: minpack.lm, abind, Matrix, methods
Encoding: UTF-8
RoxygenNote: 7.3.3
Suggests: knitr, rmarkdown, bookdown, gslnls
VignetteBuilder: knitr
NeedsCompilation: no
Packaged: 2026-03-14 17:35:46 UTC; colin
Author: Colin Smith [aut, cre]
Maintainer: Colin Smith <colin.smith@wesleyan.edu>
Repository: CRAN
Date/Publication: 2026-03-19 14:50:29 UTC

fitnmr Package Overview

Description

The functionality provided by the fitnmr package can be divided into several categories:

Spectrum reading, plotting, and analysis

Spectra in the NMRPipe file format can be read with read_nmrpipe. Those spectra can be plotted with contour_pipe. The noise level within a spectrum (or any numeric vector) can be calculated with noise_estimate.

Low-level fitting and plotting

The core fitting procedure consists of a two-step process: First, the fit input is created with make_fit_input. Second, the fit is executed with perform_fit. Prior to running the fit, constraints can be added to the fit with either update_fit_bounds or limit_omega0_by_r2.

Before or after a fit has been performed, you can extract the raw, starting, or fit spectral intensities with get_spec_int. Furthermore, there are convenience plotting functions for plotting 1D (plot_fit_1d) or 2D (plot_fit_2d) fits.

The make_fit_input function takes many different parameters. To make a new fit from an existing fit, possibly with a different set of spectra or otherwise modified fitting parameters, param_list_to_arg_list can be helpful in generating a list of parameters for make_fit_input.

Modifying parameter lists for fits

In fitnmr, a "parameter list" is a named list data structure that has all the information necessary to describe a set of peaks and interdependencies between the parameters for those peaks. It containins three elements: start_list (or also fit_list after a fit has been performed), group_list, and comb_list. Fitting constraints can also be stored in lower_list and upper_list. Each of those is itself a named list of arrays corresponding to different parameters, namely omega0, r2, m0, p0, p1, and omega0_comb. To help manage the values stored in those lists (particularly omega0 and omega0_comb), there are several convenience functions to select particular subsets, including omega0_param_idx and coupling_param_idx. Once a subset is made, the parameters can be read or changed using param_values.

High-level fitting and plotting

fit_peak_iter

param_list_to_peak_df, plot_peak_df, peak_df_to_param_list, peak_df_to_fit_input

fit_peak_cluster, fit_footprint

fit_peaks, make_param_list

spec_overlap_mat

NMRPipe simulation and processing

ppm_to_pts, whz_to_pts, write_nmrdraw_peak_tab, sim_time_nd, nmr_pipe

Postprocessing and assignment

height_assign, read_nmrdraw_peak_tab

Deprecated

extract_params, get_spec_peak_int

Author(s)

Maintainer: Colin Smith colin.smith@wesleyan.edu

See Also

Useful links:

Combine multi-dimensional arrays with lists

Description

Combine multi-dimensional arrays with lists

Usage

abind_list(..., rev.along = NULL)

Arguments

...

any number of lists with dimensions or a single list of list arrrays

rev.along

dimension to reverse before binding (passed to abind)

Collapse strings of repeated NAs in a vector with numeric names

Description

Collapse strings of repeated NAs in a vector with numeric names

Usage

collapse_na(x)

Arguments

x

1D array with dimnames having numeric positional values

Collapse blocks of NAs in an array with numeric dimension names

Description

Collapse blocks of NAs in an array with numeric dimension names

Usage

collapse_na_array(x)

Arguments

x

array with names having numeric positional values

Determine array of destination parameters from a source vector

Description

Determine array of destination parameters from a source vector

Usage

comb_vec_to_param_array(
  comb_vec,
  comb_array,
  param_array = NULL,
  na_only = FALSE
)

Arguments

comb_vec

vector of source parameters

comb_array

array of 2xN data frames with mapping between vector and array

param_array

starting array of destination parameters

na_only

only overwrite values in param_array if they are NA

Plot Spectra Contours

Description

Plot a two dimensional contour plot

Usage

contour_pipe(
  data_mat,
  nlevels = 10,
  zlim = range(data_mat, na.rm = TRUE),
  low_frac = 0.05,
  lwd = 0.25,
  main = NA,
  col_pos = "black",
  col_neg = grDevices::rgb(t(grDevices::col2rgb(col_pos))/255 * 0.25 + 0.75),
  add = FALSE,
  xlab = NULL,
  ylab = NULL,
  frame.plot = TRUE
)

Arguments

data_mat

matrix with spectral intensities.

nlevels

number of contour levels.

zlim

minimum and maximum values at which to show contours.

low_frac

minimum absolute value (as a fraction of zlim) at which to show contours.

lwd

width of contour lines.

main

title of the plot.

col_pos

color of positive contours.

col_neg

color of negative contours, defaults to lighter version of col_pos.

add

logical indicating whether to add to an existing plot (i.e. not start a new one).

xlab

label for x-axis, defaults to names(dimnames(datamat))[1].

ylab

label for y-axis, defaults to names(dimnames(datamat))[2].

frame.plot

a logical indicating whether a box should be drawn around the plot.

Details

The first dimension of data_matrix is drawn along the x-axis and the second dimension is drawn along the y-axis.

If low_frac is specified, then there can actually be up to nlevels total positive contour levels and/or nlevels total negative contour levels, whichever has the larger magnitude in zlim. The other dimension will have the mirror image of those up to the relevant limit in zlim. Note that the levels do not actually go up to zlim. There are nlevels+1 log spaced levels calculated from the contour determined by low_frac up to the maximum absolute zlim, but the final level is not drawn because it is at the maximum absolute zlim.

If low_frac is set to NA, then the contour levels are calculated in the same way as contour, with there being approximately nlevels linearly spaced levels in a range close to zlim.

Note that this function does not directly take the data returned by read_nmrpipe. You must pass the int matrix from the value returned by that function.

Value

No return value, called for side effects (draws contour lines).

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spec <- read_nmrpipe(spec_file, dim_order = "hx")
contour_pipe(spec$int)

Get a list of logical arrays indicating which parameters correspond to scalar couplings

Description

Get a list of logical arrays indicating which parameters correspond to scalar couplings

Usage

coupling_param_idx(param_list, comb_idx_offset = 0)

Arguments

param_list

parameter list

comb_idx_offset

offset for combination index mapping

Value

A named 'list' of logical index arrays/vectors (matching 'param_list$group_list') that identify scalar-coupling parameters in 'omega0_comb'.

Extract parameters from fit object for use with make_fit_input

Description

Extract parameters from fit object for use with make_fit_input

Usage

extract_params(fit, expand = 0)

Arguments

fit

fit_output structure

expand

number of empty peaks to append

Determine the region of a spectrum containing the majority of the fit peaks

Description

Determine the region of a spectrum containing the majority of the fit peaks

Usage

fit_footprint(fit, frac = 0.12)

Arguments

fit

fit_output structure

frac

fraction of total intensity used to define the footprint

Fit a cluster of nearby peaks starting from a seed table of chemical shifts

Description

Fit a cluster of nearby peaks starting from a seed table of chemical shifts

Usage

fit_peak_cluster(
  spec_list,
  cs_start,
  spec_ord,
  f_alpha_thresh = 0.001,
  omega0_plus = c(0.075, 0.75),
  r2_start = 5,
  r2_bounds = c(0.5, 20),
  sc_start = NULL,
  sc_bounds = c(0, Inf),
  plot_main_prefix = NULL,
  peak_num_offset = 0,
  plot_fit_stages = FALSE,
  verbose = TRUE
)

Arguments

spec_list

list of spectra

cs_start

matrix of starting chemical shifts

spec_ord

order of spectral dimensions

f_alpha_thresh

alpha threshold for F-test

omega0_plus

omega0 bounds for each dimension

r2_start

starting r2 values

r2_bounds

numeric vector of length 2 with r2 bounds

sc_start

starting scalar coupling values

sc_bounds

numeric vector of length 2 with scalar coupling bounds

plot_main_prefix

optional prefix for plot titles

peak_num_offset

offset added to peak numbers in plots

plot_fit_stages

logical indicating whether to plot intermediate fits

verbose

logical indicating whether to print progress updates

Value

Usually a fit-output 'list' (including 'fit_list') for the accepted peak cluster. In edge cases where no acceptable fit is retained, returns modeled intensity matrix/matrices used for subtraction.

Iterative Peak Fitting

Description

Iteratively fit peaks for whole spectra

Usage

fit_peak_iter(
  spectra,
  noise_sigma = NULL,
  noise_cutoff = 15,
  f_alpha = 0.001,
  iter_max = 100,
  omega0_plus = c(0.075, 0.75),
  r2_start = 5,
  r2_bounds = c(0.5, 20),
  sc_start = c(6, NA),
  sc_bounds = c(2, 12),
  fit_list = list(),
  plot_fit = FALSE,
  plot_fit_stages = FALSE,
  iter_callback = NULL,
  verbose = TRUE
)

Arguments

spectra

list of spectrum objects read by read_nmrpipe.

noise_sigma

numeric vector of noise levels associated with each spectrum. If NULL, it is calculated with noise_estimate.

noise_cutoff

numeric value multiplied by noise_sigma to determine cutoffs for each spectrum. Peak fitting will terminate if the maximum residuals for all spectra fall below these cutoffs.

f_alpha

numeric value giving a F-test p-value threshold above which a peak will not be accepted.

iter_max

integer maximum number of iterations to apply.

omega0_plus

numeric vector giving the window size (ppm plus or minus the starting omega0 values) around which to use points from the spectra for fitting.

r2_start

numeric vector giving the starting r2 value(s) for the fit (in Hz).

r2_bounds

numeric vector of length two giving the lower and upper bounds for r2.

sc_start

numeric vector giving the starting scalar coupling values for doublets. It should be the same length as the number of dimensions in the spectrum. Set the value to NA for a given dimension to make it a singlet.

sc_bounds

numeric vector of length two giving the lower and upper bounds for scalar couplings.

fit_list

list of previous fits to which the new fits should be appended.

plot_fit

logical indicating whether produce a fit cluster plot for each iteration.

plot_fit_stages

logical indicating whether to plot each stage of fitting within the iterations.

iter_callback

function called after each iteration with two arguments: iter and iter_max

verbose

logical indicating whether to print progress updates

Details

This function uses an iterative algorithm to fit all the peaks in a given list of spectra, assuming identical peak positions and shapes across the spectra. Each iteration starts by identifying the maximum value across all spectra, using that position to fit a cluster of overlapping peaks with the fit_peak_cluster function. After the cluster of peaks is fit, the modeled intensity is subtracted from all spectra and another iteration is performed. Iterations are terminated if max_iter is reached or the residual intensity in all spectra falls below noise_sigma*noise_cutoff.

This function currently only supports fitting of 2D spectra, but will be generalized to work with spectra of any dimensionality in the near future. To reduce the number of false positives/negatives, the most important parameters to adjust are noise_cutoff, f_alpha, and iter_max. If iter_max is reached before all peaks have been identified, then you can call this function again, setting the fit_list parameter to the return value of the previous invocation. In that case, iter_max new iterations will be performed and appended to fit_list.

For visualizing the iterative algorithm as it progresses, you can enable either the plot_fit or plot_fit_stages parameters.

Value

List of fit objects returned by fit_peak_cluster, one for each iteration. They are appended to fit_list if supplied.

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spec <- list("1.ft2" = read_nmrpipe(spec_file, dim_order = "hx"))
peak_fits <- fit_peak_iter(spec, iter_max = 2)

Fit peaks from a table of chemical shifts

Description

Fit peaks from a table of chemical shifts

Usage

fit_peaks(
  spec_list,
  cs_mat,
  fit_prev = NULL,
  spec_ord = 1:2,
  omega0_plus = c(0.075, 0.75),
  r2_start = 5,
  r2_bounds = c(0.5, 20),
  sc_start = NULL,
  sc_bounds = c(0, Inf),
  positive_only = TRUE,
  plot_fit_stages = TRUE
)

Arguments

spec_list

list of spectra

cs_mat

matrix of chemical shifts

fit_prev

optional previous fit parameters

spec_ord

order of spectral dimensions

omega0_plus

omega0 bounds for each dimension

r2_start

starting r2 values

r2_bounds

numeric vector of length 2 with r2 bounds

sc_start

starting scalar coupling values

sc_bounds

numeric vector of length 2 with scalar coupling bounds

positive_only

logical indicating whether to constrain m0 to be positive

plot_fit_stages

logical indicating whether to plot intermediate fits

Value

A fitted parameter 'list' (fit-output structure) containing fitted values in 'fit_list' plus the original fit metadata and bounds.

Get arrays of spectral intensities for input, starting parameters, and fit peaks

Description

Get arrays of spectral intensities for input, starting parameters, and fit peaks

Usage

get_spec_int(
  fit_data,
  spec_type = c("input", "start", "fit"),
  spec_idx = seq_along(fit_data$spec_data),
  peak_idx = seq_len(dim(fit_data$start_list$omega0)[2])
)

Arguments

fit_data

fit_input or fit_output structure

spec_type

character indicating which spectra to return

spec_idx

indices of spectra to return

peak_idx

indices of peaks to include (for start/fit)

Value

A 'list' of numeric arrays, one per selected spectrum. Each array is on contiguous ppm axes and contains either observed ('input') or modeled ('start'/'fit') intensities.

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spec <- read_nmrpipe(spec_file, dim_order = "hx")
fit_input <- make_fit_input(
  list(spec),
  omega0_start = matrix(c(8.5400, 119.76), nrow = 2),
  omega0_plus = c(0.075, 0.75),
  r2_start = 4,
  m0_start = 1e9
)
input_int <- get_spec_int(fit_input, "input")
start_int <- get_spec_int(fit_input, "start")

Get spectra for individual peaks

Description

Get spectra for individual peaks

Usage

get_spec_peak_int(
  fit_data,
  spec_type = c("start", "fit"),
  spec_idx = seq_along(fit_data$spec_data),
  peak_idx = seq_len(dim(fit_data$start_list$omega0)[2])
)

Arguments

fit_data

fit_input or fit_output structure

spec_type

character indicating which spectra to return

spec_idx

indices of spectra to return

peak_idx

indices of peaks to include

Calculate mapping from assigned peak list onto an unknown peak list

Description

This uses a greedy algorithm. It iterates over the unknown peaks in order of decreasing height and assigns each unknown to the closest assigned peak within a distance determined by the thresh parameter, as long as that peak wasn't already assigned.

Usage

height_assign(assigned, unknown, thresh = 0.01)

Arguments

assigned

two column matrix with assigned peak chemical shifts

unknown

three column matrix with unknown peak chemical shifts and heights

thresh

maximum distance (as a fraction of the two chemical shift ranges)

Value

An integer vector of length 'nrow(assigned)' giving matched row indices in 'unknown' (or 'NA' when unmatched). The 'thresh' attribute stores the effective distance thresholds in each dimension.

Infer acquisition time for each dimension

Description

Infer acquisition time for each dimension

Usage

infer_acquisition_time(fheader, empirically_correct = TRUE)

Arguments

fheader

matrix of generalized ND parameters

empirically_correct

logical indicating whether to apply empirical correction

Infer which dimension was directly acquired

Description

Infer which dimension was directly acquired

Usage

infer_aliasing(fheader, phase_tolerance = 10)

Arguments

fheader

matrix of generalized ND parameters

phase_tolerance

tolerance in degrees for detecting half-dwell delay

Infer which dimension was directly acquired

Description

Infer which dimension was directly acquired

Usage

infer_direct(fheader)

Arguments

fheader

matrix of generalized ND parameters

Infer original sweep width for each dimension

Description

Infer original sweep width for each dimension

Usage

infer_sweep_width(fheader)

Arguments

fheader

matrix of generalized ND parameters

Add upper/lower limits based on the r2 value

Description

Add upper/lower limits based on the r2 value

Usage

limit_omega0_by_r2(fit_input, factor = 1.5)

Arguments

fit_input

fit_input structure

factor

multiplier applied to r2 to set omega0 bounds

Value

A modified 'fit_input' list with updated 'lower_list$omega0' and 'upper_list$omega0' bounds.

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spec <- read_nmrpipe(spec_file, dim_order = "hx")
fit_input <- make_fit_input(
  list(spec),
  omega0_start = matrix(c(8.5400, 119.76), nrow = 2),
  omega0_plus = c(0.075, 0.75),
  r2_start = 4,
  m0_start = 1e9
)
fit_input$start_list[1:2]
fit_input$lower_list[1]
fit_input$upper_list[1]
fit_input <- limit_omega0_by_r2(fit_input)
fit_input$lower_list[1]
fit_input$upper_list[1]

Make a multiplet matrix with weights and scalar coupling coefficients

Description

Make a multiplet matrix with weights and scalar coupling coefficients

Usage

make_coupling_mat(sc_names)

Arguments

sc_names

character vector with names of scalar couplings

Prepare input data structure for peak fitting

Description

Prepare input data structure for peak fitting

Usage

make_fit_input(
  spectra,
  omega0_start,
  omega0_plus,
  omega0_minus = omega0_plus,
  omega0_trunc = NULL,
  r2_start = NULL,
  m0_start = NULL,
  m0_region = (omega0_plus + omega0_minus)/2,
  p0_start = 0,
  p1_start = 0,
  omega0_group = NULL,
  r2_group = NULL,
  m0_group = NULL,
  p0_group = 0,
  p1_group = 0,
  omega0_comb = NULL,
  omega0_comb_start = NULL,
  omega0_comb_group = NULL,
  coupling_comb = NULL,
  resonance_names = NULL,
  nucleus_names = NULL,
  field_offsets = numeric(),
  field_start = numeric(),
  field_group = 0,
  fheader = NULL
)

Arguments

spectra

list of spectra or data frame with ppm and intensity columns

omega0_start

starting omega0 values

omega0_plus

positive omega0 bounds

omega0_minus

negative omega0 bounds

omega0_trunc

optional truncation bounds for omega0

r2_start

starting r2 values

m0_start

starting m0 values

m0_region

region for m0 estimation

p0_start

starting zero-order phase values

p1_start

starting first-order phase values

omega0_group

grouping for omega0 values

r2_group

grouping for r2 values

m0_group

grouping for m0 values

p0_group

grouping for p0 values

p1_group

grouping for p1 values

omega0_comb

list of omega0 combination matrices

omega0_comb_start

starting omega0 combination values

omega0_comb_group

grouping for omega0 combinations

coupling_comb

list of coupling combination matrices

resonance_names

optional resonance names

nucleus_names

optional nucleus names

field_offsets

matrix of field offsets

field_start

starting field values

field_group

grouping for field values

fheader

optional fheader matrix when spectra is a data frame

Value

A 'fit_input' 'list' containing 'spec_data', parameter lists ('start_list', 'group_list', 'comb_list'), parameter bounds ('lower_list', 'upper_list'), naming metadata, and 'num_points'.

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spec <- read_nmrpipe(spec_file, dim_order = "hx")
fit_input <- make_fit_input(
  list(spec),
  omega0_start = matrix(c(8.5400, 119.76), nrow = 2),
  omega0_plus = c(0.075, 0.75),
  r2_start = 4,
  m0_start = 1e9
)
str(fit_input)

Create a sparse axis map

Description

Create a sparse axis map

Usage

make_map(
  x,
  max_spacing = 0.125,
  new_spacing = 0.025,
  starts = NULL,
  ends = NULL
)

Arguments

x

numeric vector or array used to define the sparse axis

max_spacing

maximum spacing between segments before inserting a gap

new_spacing

spacing used for the inserted gap

starts

optional numeric vector of segment start positions

ends

optional numeric vector of segment end positions

Value

A two-column numeric matrix mapping original coordinates (column 1) to sparse-axis coordinates (column 2), with 'starts' and 'ends' attributes giving segment boundaries.

Make a parameter list for a set of spectra and chemical shifts

Description

Make a parameter list for a set of spectra and chemical shifts

Usage

make_param_list(
  spec_list,
  cs_mat,
  fit_prev = NULL,
  r2_start = 5,
  m0_start = 1,
  sc_start = NULL,
  same_r2 = FALSE,
  same_coupling = FALSE
)

Arguments

spec_list

list of spectra

cs_mat

matrix of chemical shifts

fit_prev

optional previous fit parameters

r2_start

starting r2 values

m0_start

starting m0 values

sc_start

starting scalar coupling values

same_r2

logical indicating whether to tie r2 across dimensions

same_coupling

logical indicating whether to tie coupling across dimensions

Value

A parameter 'list' with 'start_list', 'group_list', and 'comb_list' components that can be passed to 'make_fit_input()'.

Process an FID with NMRPipe

Description

Process an FID with NMRPipe

Usage

nmr_pipe(
  in_path,
  out_path,
  ndim = 1,
  apod = NULL,
  sp = rbind(off = 0.5, end = 1, pow = 1, c = 0.5),
  zf = rbind(auto = ""),
  ps = rbind(p0 = 0, p1 = 0, di = ""),
  ext = NULL
)

Arguments

in_path

input file path

out_path

output file path

ndim

number of dimensions

apod

optional apodization argument matrix

sp

optional sine-bell argument matrix

zf

optional zero-fill argument matrix

ps

optional phase correction argument matrix

ext

optional extraction argument matrix

Value

The integer exit status from 'system(...)' (typically '0' on success).

Fourier transform a 1D FID

Description

This function aims to numerically match the NMRPipe 'FT' function.

Usage

nmrpipe_ft(fid)

Arguments

fid

list with 'int', 'header', and 'fheader' elements containing FID data

Details

See the NMRPipe documentation: https://www.nmrscience.com/ref/nmrpipe/ft.html

Value

A transformed spectrum 'list' with updated 'int', 'ppm', 'header', and 'fheader' fields.

Examples

fid_path <- system.file("extdata", "noesy1d", "11", "test.fid", package = "fitnmr")
fid <- read_nmrpipe(fid_path, complex_data = TRUE)
sp <- nmrpipe_sp(fid)
zf <- nmrpipe_zf(sp)
ft <- nmrpipe_ft(zf)

Inverse Fourier transform a 1D spectrum

Description

This function aims to numerically match the NMRPipe 'FT -inv' function.

Usage

nmrpipe_fti(ft)

Arguments

ft

list with 'int', 'header', and 'fheader' elements containing spectrum data

Details

See the NMRPipe documentation: https://www.nmrscience.com/ref/nmrpipe/ft.html

Value

A modified FID-like 'list' with inverse-transformed 'int' values and updated 'header'/'fheader' metadata.

Examples

fid_path <- system.file("extdata", "noesy1d", "11", "test.fid", package = "fitnmr")
fid <- read_nmrpipe(fid_path, complex_data = TRUE)
sp <- nmrpipe_sp(fid)
zf <- nmrpipe_zf(sp)
ft <- nmrpipe_ft(zf)
fti <- nmrpipe_fti(ft)

Inverse Fourier transform a 1D spectrum

Description

This function aims to numerically match the NMRPipe 'PS' function.

Usage

nmrpipe_ps(ft, p0 = 0, p1 = 0)

Arguments

ft

list with 'int', 'header', and 'fheader' elements containing spectrum data

p0

equivalent to '-p0' flag

p1

equivalent to '-p1' flag

Details

See the NMRPipe documentation: https://www.nmrscience.com/ref/nmrpipe/ps.html

Value

A modified spectrum 'list' with phase-corrected 'int' values and updated phase metadata in 'header' and 'fheader'.

Examples

fid_path <- system.file("extdata", "noesy1d", "11", "test.fid", package = "fitnmr")
fid <- read_nmrpipe(fid_path, complex_data = TRUE)
sp <- nmrpipe_sp(fid)
zf <- nmrpipe_zf(sp)
ft <- nmrpipe_ft(zf)
ps <- nmrpipe_ps(ft, p0 = 129, p1 = 3)

Apply sine-based window function to a 1D FID

Description

This function aims to numerically match the NMRPipe 'SP' function.

Usage

nmrpipe_sp(fid, off = 0, end = 1, pow = 1, cval = 1, dmx = FALSE)

Arguments

fid

list with 'int', 'header', and 'fheader' elements containing FID data

off

equivalent to '-off' flag

end

equivalent to '-end' flag

pow

equivalent to '-pow' flag

cval

equivalent to '-c' flag

dmx

equivalent to '-dmx' flag

Details

See the NMRPipe documentation: https://www.nmrscience.com/ref/nmrpipe/sp.html

Value

A modified FID 'list' with updated 'int', 'header', and 'fheader' values after sine-bell apodization.

Examples

fid_path <- system.file("extdata", "noesy1d", "11", "test.fid", package = "fitnmr")
fid <- read_nmrpipe(fid_path, complex_data = TRUE)
sp <- nmrpipe_sp(fid)

Apply zero filling to a 1D FID

Description

This function aims to numerically match the NMRPipe 'ZF' function.

Usage

nmrpipe_zf(fid, zf = 1, pad = NULL, size = NULL, auto = FALSE)

Arguments

fid

list with 'int', 'header', and 'fheader' elements containing FID data

zf

equivalent to '-zf' flag

pad

equivalent to '-pad' flag

size

equivalent to '-size' flag

auto

equivalent to '-auto' flag

Details

See the NMRPipe documentation: https://www.nmrscience.com/ref/nmrpipe/zf.html

Value

A modified FID 'list' with zero-filled 'int' data and updated 'header'/'fheader' metadata.

Examples

fid_path <- system.file("extdata", "noesy1d", "11", "test.fid", package = "fitnmr")
fid <- read_nmrpipe(fid_path, complex_data = TRUE)
sp <- nmrpipe_sp(fid)
zf <- nmrpipe_zf(sp)

Estimate Noise

Description

Estimate properties of noise by fitting a Gaussian to a histogram of intensities

Usage

noise_estimate(
  x,
  height = TRUE,
  thresh = 10,
  plot_distributions = TRUE,
  peak_intensities = NULL
)

Arguments

x

numeric values for which to estimate noise.

height

logical indicating whether to use Gaussian function whose area is not fixed at one because of an additional height scaling factor.

thresh

numeric value specifying the factor by which to multiply the standard deviation to determine the threshold away from the mean value within which to include values for the next iteration and final histogram for fitting.

plot_distributions

logical indicating whether to plot the distribution and Gaussian fit used to estimate the noise.

peak_intensities

numeric values of peak intensities to determine the signal to noise.

Details

This function estimates noise using iterative calculation of the mean and standard deviation, followed by fitting a Gaussian function to a histogram of the values within a range determined at the end of the iterations.

The iterative algorithm first calculates the mean and standard deviation of the values in x. In the next iteration, only points within thresh times the standard deviation of the mean value are used for calculating a new mean and standard deviation. This is repeated 20 times. A histogram with 512 bins is then computed within a range determined from the final mean and standard deviation. The returned parameters are based on a Gaussian fit to this histogram.

Value

a named numeric vector with values:

mean

mean value from the Gaussian fit

mu

standard deviation from the Gaussian fit

h

height of Gaussian fit (optional depending on value of height parameter)

max

maximum value of x

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package="fitnmr")
spec <- read_nmrpipe(spec_file, dim_order="hx")
noise_estimate(spec$int)

Get the first index in the omega0 array corresponding to each TRUE value in omega0_idx

Description

Get the first index in the omega0 array corresponding to each TRUE value in omega0_idx

Usage

omega0_comb_source_idx(param_list, omega0_idx = omega0_param_idx(param_list))

Arguments

param_list

parameter list

omega0_idx

logical index list for omega0 parameters

Get a list of logical arrays indicating which parameters correspond to peak positions

Description

Get a list of logical arrays indicating which parameters correspond to peak positions

Usage

omega0_param_idx(
  param_list,
  dims = seq_len(dim(param_list[["group_list"]][["omega0"]])[1]),
  peaks = seq_len(dim(param_list[["group_list"]][["omega0"]])[2]),
  specs = seq_len(dim(param_list[["group_list"]][["omega0"]])[3])
)

Arguments

param_list

parameter list

dims

dimensions to include

peaks

peaks to include

specs

spectra to include

Value

A named 'list' of logical index arrays/vectors (matching 'param_list$group_list') that identify omega0-related parameters to extract or modify.

Determine vector of source parameters from destination array via least squares

Description

Determine vector of source parameters from destination array via least squares

Usage

param_array_to_comb_vec(
  param_array,
  comb_array,
  group_vec = NULL,
  resid_thresh = 1e-08
)

Arguments

param_array

array of destination parameters

comb_array

array of 2xN data frames with mapping between vector and array

group_vec

optional vector of group numbers for source parameters

resid_thresh

all residuals from least squares fit must be less than this value

Convert a list of parameters for use with make_fit_input

Description

Convert a list of parameters for use with make_fit_input

Usage

param_list_to_arg_list(param_list)

Arguments

param_list

parameter list

Value

A flattened, named 'list' of arguments suitable for 'do.call()' with 'make_fit_input()'.

Convert Fit to Data Frame

Description

Convert a parameter list into a peak data frame

Usage

param_list_to_peak_df(param_list, spec_names = NULL)

Arguments

param_list

list of fit parameters (or a list of such lists)

spec_names

character vector of spectrum names

Details

This function takes the input or (if present) output parameters from a fit and converts them into a data frame. A parameter list must contain three lists:

start_list or fit_list

input or output values of the respective fit parameters

group_list

group numbers for the fit parameters

comb_list

coefficients for deriving fit parameters from a linear combination other auxiliary parameters

This function currently assumes the fit parameters were generated by fit_peak_iter, fit_peak_cluster, or peak_df_to_param_list. These functions use a particular convention for group_list and comb_list to represent either singlets or doublets in each dimension of a 2D spectrum.

This function can take either a single parameter list or a list of parameter lists. If the latter is given, then the results from all the parameter lists will be combined into a single table.

Value

A data frame with the following columns:

peak

peak number

fit

fit cluster number, with all peaks in the same cluster having the same r2, scalar couplings, and m0

f_pvalue

optional, p-value determined from F-test during iterative fitting

omega0_ppm_1

chemical shift of singlet/doublet center in the first dimension (ppm)

omega0_ppm_2

chemical shift of singlet/doublet center in the second dimension (ppm)

sc_hz_1

optional, scalar coupling of doublet in first dimension (Hz)

sc_hz_2

optional, scalar coupling of doublet in second dimension (Hz)

r2_hz_1

R2 in first dimension (Hz)

r2_hz_2

R2 in first dimension (Hz)

...

m0 values for each spectrum

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spec <- list("1.ft2" = read_nmrpipe(spec_file, dim_order = "hx"))
peak_fits <- fit_peak_iter(spec, iter_max = 2)
param_list_to_peak_df(peak_fits)

Convert a parameter list into a set of tables with resonance/nuclei/couplings

Description

Convert a parameter list into a set of tables with resonance/nuclei/couplings

Usage

param_list_to_tables(param_list, tables)

Arguments

param_list

param_list, fit_input, or fit_output structure

tables

list with resonance/nuclei/couplings tables to update

Value

A named 'list' with updated 'resonances', 'nuclei', and 'couplings' data frames.

Examples

spec_file <- system.file("extdata", "tyrosine", "proton.ft1", package = "fitnmr")
spec <- read_nmrpipe(spec_file)

start_resonances <- structure(
  list(
    x = c("HA", "HB3", "HB2", "HD1/2", "HE1/2"),
    x_sc = c(
      "HA-HB3 HA-HB2",
      "HA-HB3 HB3-HB2",
      "HA-HB2 HB3-HB2",
      "HD1/2-HE1/2-3 HD1/2-HE1/2-5",
      "HD1/2-HE1/2-3 HD1/2-HE1/2-5"
    )
  ),
  row.names = c("HA", "HB3", "HB2", "HD1/2", "HE1/2"),
  class = "data.frame"
)

start_nuclei <- structure(
  list(
    omega0_ppm = c(3.364, 2.635, 2.799, 6.94, 6.538),
    r2_hz = c(0.7, 0.7, 0.7, 0.7, 0.7)
  ),
  class = "data.frame",
  row.names = c("HA", "HB3", "HB2", "HD1/2", "HE1/2")
)

start_couplings <- structure(
  list(hz = c(7.153, 5.159, -13.941, 7.7, 2)),
  class = "data.frame",
  row.names = c("HA-HB3", "HA-HB2", "HB3-HB2", "HD1/2-HE1/2-3", "HD1/2-HE1/2-5")
)

start_tables <- list(
  resonances = start_resonances,
  nuclei = start_nuclei,
  couplings = start_couplings
)
param_list <- tables_to_param_list(list(spec), start_tables)
param_list$start_list$m0[] <- 1e9
arg_list <- param_list_to_arg_list(param_list)
fit_input <- do.call(make_fit_input, c(list(list(spec), omega0_plus = 0.075), arg_list))
fit_output <- perform_fit(fit_input)
fit_tables <- param_list_to_tables(fit_output, start_tables)

Get/set a subset of fitting parameters specified by a list of logical vectors

Description

Get/set a subset of fitting parameters specified by a list of logical vectors

Usage

param_values(params, idx_list)

param_values(params, idx_list) <- value

Arguments

params

a list of fitting parameters

idx_list

a list with the same structure as params but with logical vectors indicating which values should be return/set

value

replacement values (for setter)

Value

a vector of parameter values or the modified parameter list

Combine parameter lists referring to different peaks

Description

Combine parameter lists referring to different peaks

Usage

peak_bind(...)

Arguments

...

any number of parameter lists or a single list of parameter lists

Convert a peak data frame to fit input

Description

Convert a peak data frame to fit input

Usage

peak_df_to_fit_input(peak_df, spectra, ...)

Arguments

peak_df

data frame of peak parameters

spectra

list of spectra

...

additional arguments passed to make_fit_input

Value

A 'fit_input' list ready for optimization, as produced by 'make_fit_input()'.

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spectra <- list("1.ft2" = read_nmrpipe(spec_file, dim_order = "hx"))

peak_df <- data.frame(
  peak = c(1, 2, 3, 4),
  fit = c(1, 1, 2, 2),
  f_pvalue = c(4.566421e-10, 1.118991e-05, 1.876528e-15, 5.817124e-04),
  omega0_ppm_1 = c(8.247602, 8.259565, 8.540030, 8.520232),
  omega0_ppm_2 = c(121.8666, 121.9299, 119.7611, 119.7266),
  sc_hz_1 = c(3.280589, 3.280589, 2.000000, 2.000000),
  r2_hz_1 = c(2.907218, 2.907218, 4.788566, 4.788566),
  r2_hz_2 = c(2.334497, 2.334497, 2.099646, 2.099646),
  `1.ft2` = c(824420657, 240560662, 1020008726, 89977216),
  check.names = FALSE
)

fit_input <- peak_df_to_fit_input(peak_df, spectra, omega0_plus=c(0.075, 0.75))

Convert a peak data frame to a parameter list

Description

Convert a peak data frame to a parameter list

Usage

peak_df_to_param_list(peak_df, spectra)

Arguments

peak_df

data frame of peak parameters

spectra

list of spectra

Value

A parameter 'list' with 'start_list', 'group_list', and 'comb_list' inferred from 'peak_df' and aligned to 'spectra'.

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spectra <- list("1.ft2" = read_nmrpipe(spec_file, dim_order = "hx"))

peak_df <- data.frame(
  peak = c(1, 2, 3, 4),
  fit = c(1, 1, 2, 2),
  f_pvalue = c(4.566421e-10, 1.118991e-05, 1.876528e-15, 5.817124e-04),
  omega0_ppm_1 = c(8.247602, 8.259565, 8.540030, 8.520232),
  omega0_ppm_2 = c(121.8666, 121.9299, 119.7611, 119.7266),
  sc_hz_1 = c(3.280589, 3.280589, 2.000000, 2.000000),
  r2_hz_1 = c(2.907218, 2.907218, 4.788566, 4.788566),
  r2_hz_2 = c(2.334497, 2.334497, 2.099646, 2.099646),
  `1.ft2` = c(824420657, 240560662, 1020008726, 89977216),
  check.names = FALSE
)

peak_df_to_param_list(peak_df, spectra)

Perform a fit with an input data structure

Description

Perform a fit with an input data structure

Usage

perform_fit(
  fit_input,
  method = c("minpack.lm", "gslnls", "sparseLM", "L-BFGS-B"),
  ...
)

Arguments

fit_input

fit_input structure

method

fitting method

...

additional arguments passed to the fitting routine

Value

The input 'fit_input' list, augmented with fitted parameters in 'fit_list' and fit diagnostics in 'fit_rsstrace', 'fit_counts', and 'fit_time'.

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spec <- read_nmrpipe(spec_file, dim_order = "hx")
fit_input <- make_fit_input(
  list(spec),
  omega0_start = matrix(c(8.5400, 119.76), nrow = 2),
  omega0_plus = c(0.075, 0.75),
  r2_start = 4,
  m0_start = 1e9
)
fit_output <- perform_fit(fit_input)
fit_output$start_list[1:3]
fit_output$fit_list[1:3]

Plot a one dimensional peak fit

Description

Plot a one dimensional peak fit

Usage

plot_fit_1d(fit_data, always_show_start = FALSE)

Arguments

fit_data

fit_input or fit_output structure

always_show_start

logical indicating whether to show starting model when fit is present

Value

No return value, called for side effects (draws plots).

Examples

spec_file <- system.file("extdata", "tyrosine", "proton.ft1", package = "fitnmr")
spec <- read_nmrpipe(spec_file)

start_resonances <- structure(
  list(
    x = c("HA", "HB3", "HB2", "HD1/2", "HE1/2"),
    x_sc = c(
      "HA-HB3 HA-HB2",
      "HA-HB3 HB3-HB2",
      "HA-HB2 HB3-HB2",
      "HD1/2-HE1/2-3 HD1/2-HE1/2-5",
      "HD1/2-HE1/2-3 HD1/2-HE1/2-5"
    )
  ),
  row.names = c("HA", "HB3", "HB2", "HD1/2", "HE1/2"),
  class = "data.frame"
)

start_nuclei <- structure(
  list(
    omega0_ppm = c(3.364, 2.635, 2.799, 6.94, 6.538),
    r2_hz = c(0.7, 0.7, 0.7, 0.7, 0.7)
  ),
  class = "data.frame",
  row.names = c("HA", "HB3", "HB2", "HD1/2", "HE1/2")
)

start_couplings <- structure(
  list(hz = c(7.153, 5.159, -13.941, 7.7, 2)),
  class = "data.frame",
  row.names = c("HA-HB3", "HA-HB2", "HB3-HB2", "HD1/2-HE1/2-3", "HD1/2-HE1/2-5")
)

start_tables <- list(
  resonances = start_resonances,
  nuclei = start_nuclei,
  couplings = start_couplings
)
param_list <- tables_to_param_list(list(spec), start_tables)
param_list$start_list$m0[] <- 1e9
arg_list <- param_list_to_arg_list(param_list)
fit_input <- do.call(make_fit_input, c(list(list(spec), omega0_plus = 0.075), arg_list))
fit_output <- perform_fit(fit_input)
plot_fit_1d(fit_output)

Plot a two dimensional peak fit

Description

Plot a two dimensional peak fit

Usage

plot_fit_2d(
  fit_output,
  spec_ord = seq_len(dim(fit_output$start_list$omega0)[1]),
  always_show_start = FALSE,
  main = NULL
)

Arguments

fit_output

fit_output structure

spec_ord

order of spectral dimensions to plot

always_show_start

logical indicating whether to show starting model when fit is present

main

optional title for the plot

Value

No return value, called for side effects (draws plots).

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spec <- read_nmrpipe(spec_file, dim_order = "hx")
fit_input <- make_fit_input(
  list(spec),
  omega0_start = matrix(c(8.5400, 119.76), nrow = 2),
  omega0_plus = c(0.075, 0.75),
  r2_start = 4,
  m0_start = 1e9
)
plot_fit_2d(fit_input)

Plot Peaks from a Peak Table

Description

Plot fits for series of spectra with parameters from a peak data frame

Usage

plot_peak_df(
  peak_df,
  spectra,
  noise_sigma = NULL,
  noise_cutoff = 4,
  omega0_plus = c(0.075, 0.75) * 2,
  cex = 0.2,
  lwd = 0.25,
  label = TRUE,
  label_col = "black",
  p0 = NULL,
  p1 = NULL,
  add = FALSE
)

Arguments

peak_df

data frame with peak data as produced by param_list_to_peak_df.

spectra

list of spectra corresponding to the volumes found in peak_df.

noise_sigma

numeric vector of noise levels associated with each spectrum. If NULL, it is calculated with noise_estimate.

noise_cutoff

numeric value used to calculate the lowest contour level according to noise_sigma*noise_cutoff.

omega0_plus

omega0 bounds for plotting

cex

numeric value by which to scale blue points and labels.

lwd

numeric value giving width of contour lines.

label

logical indicating whether to draw text labels and connecting lines.

label_col

color for text labels

p0

zero order phase for plotting modeled peaks.

p1

first order phase for plotting modeled peaks.

add

logical indicating whether to suppress generation of a new plot and add to an existing plot.

Details

The raw spectral data is shown in black contours and the modeled peak intensity is shown in red. The centers of peaks are shown with semi-transparent blue dots, with the area of the dot proportional to the volume of the peak (m0). Blue lines connect peaks from modeled doublets. Singlets or doublets are labeled with the syntax <peak>:<fit>. If an F-test p-value column is present (f_pvalue), that will be given below the peak label.

Value

No return value, called for side effects (draws plots).

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spec <- read_nmrpipe(spec_file, dim_order = "hx")

peak_df <- data.frame(
  peak = 1:8,
  fit = c(1, 1, 2, 2, 3, 3, 3, 3),
  f_pvalue = c(4.5664e-10, 1.1190e-05, 1.8765e-15, 5.8171e-04,
               7.5270e-13, 2.5923e-27, 1.3424e-05, 1.4680e-13),
  omega0_ppm_1 = c(8.2476, 8.2596, 8.5400, 8.5202, 8.6124, 8.5853, 8.6449, 8.5370),
  omega0_ppm_2 = c(121.87, 121.93, 119.76, 119.73, 123.36, 123.03, 123.47, 122.96),
  sc_hz_1 = c(3.2806, 3.2806, 2.0000, 2.0000, 7.6481, 7.6481, 7.6481, 7.6481),
  r2_hz_1 = c(2.9072, 2.9072, 4.7886, 4.7886, 5.2849, 5.2849, 5.2849, 5.2849),
  r2_hz_2 = c(2.3345, 2.3345, 2.0996, 2.0996, 2.1801, 2.1801, 2.1801, 2.1801),
  `1.ft2` = c(824420657, 240560662, 1020008726, 89977216,
              848579189, 607904936, 147984411, 161971930),
  check.names = FALSE
)

plot_peak_df(peak_df, list("1.ft2" = spec), cex = 0.6)

Plot resonances from 1D fit

Description

Plot resonances from 1D fit

Usage

plot_resonances_1d(fit_data, always_show_start = FALSE, omega0_plus = 0.05)

Arguments

fit_data

fit_input or fit_output structure

always_show_start

show start parameters even if fit already done

omega0_plus

length 3 vector giving ppm range for each dimension

Value

No return value, called for side effects (draws one or more plots).

Examples

spec_file <- system.file("extdata", "tyrosine", "proton.ft1", package = "fitnmr")
spec <- read_nmrpipe(spec_file)

start_resonances <- structure(
  list(
    x = c("HA", "HB3", "HB2", "HD1/2", "HE1/2"),
    x_sc = c(
      "HA-HB3 HA-HB2",
      "HA-HB3 HB3-HB2",
      "HA-HB2 HB3-HB2",
      "HD1/2-HE1/2-3 HD1/2-HE1/2-5",
      "HD1/2-HE1/2-3 HD1/2-HE1/2-5"
    )
  ),
  row.names = c("HA", "HB3", "HB2", "HD1/2", "HE1/2"),
  class = "data.frame"
)

start_nuclei <- structure(
  list(
    omega0_ppm = c(3.364, 2.635, 2.799, 6.94, 6.538),
    r2_hz = c(0.7, 0.7, 0.7, 0.7, 0.7)
  ),
  class = "data.frame",
  row.names = c("HA", "HB3", "HB2", "HD1/2", "HE1/2")
)

start_couplings <- structure(
  list(hz = c(7.153, 5.159, -13.941, 7.7, 2)),
  class = "data.frame",
  row.names = c("HA-HB3", "HA-HB2", "HB3-HB2", "HD1/2-HE1/2-3", "HD1/2-HE1/2-5")
)

start_tables <- list(
  resonances = start_resonances,
  nuclei = start_nuclei,
  couplings = start_couplings
)
param_list <- tables_to_param_list(list(spec), start_tables)
param_list$start_list$m0[] <- 1e9
arg_list <- param_list_to_arg_list(param_list)
fit_input <- do.call(make_fit_input, c(list(list(spec), omega0_plus = 0.075), arg_list))
fit_output <- perform_fit(fit_input)
plot_resonances_1d(fit_output, always_show_start = FALSE, omega0_plus = 0.075)

Plot resonances from 2D fit

Description

Plot resonances from 2D fit

Usage

plot_resonances_2d(
  fit_data,
  omega0_plus,
  resonances = unique(fit_data$resonance_names),
  low_frac = 0.05,
  field = TRUE,
  proj_frac = 0.2
)

Arguments

fit_data

fit_input or fit_output structure

omega0_plus

length 2 vector giving ppm range for each dimension

resonances

character vector with resonances to plot

low_frac

minimum absolute value (as a fraction of maximum intensity) at which to show contours

field

logical indicating whether to show modeling of field inhomogeneity as separate peaks

proj_frac

fraction of plot area reserved for 1D projections

Value

No return value, called for side effects (draws one plot layout per resonance).

Plot resonances from 3D fit

Description

Plot resonances from 3D fit

Usage

plot_resonances_3d(
  fit_data,
  omega0_plus,
  resonances = unique(fit_data$resonance_names)
)

Arguments

fit_data

fit_input or fit_output structure

omega0_plus

length 3 vector giving ppm range for each dimension

resonances

character vector with resonances to plot

Value

No return value, called for side effects (draws one set of projections per resonance).

Plot spectrum from 1D fit

Description

Plot spectrum from 1D fit

Usage

plot_sparse_1d(
  fit_data,
  tables = NULL,
  spec_idx = 1,
  col_model = 2,
  col_resonance = NULL,
  lwd = 1,
  tick_spacing = 0.02,
  coupling_spacing = 0.01,
  coupling_marks = 0.009,
  xaxs = "i",
  yaxt = "n",
  bty = "n",
  always_show_start = FALSE,
  add = FALSE,
  ppm_map = make_map(get_spec_int(fit_data, "input", spec_idx)[[1]])
)

Arguments

fit_data

fit_input or fit_output structure

tables

list with resonances, nuclei, and couplings tables

spec_idx

index of spectrum to plot

col_model

color for modeled peak shapes

col_resonance

colors for resonances

lwd

line width

tick_spacing

spacing between axis ticks (ppm)

coupling_spacing

spacing between coupling annotations (fraction of plot)

coupling_marks

size of coupling tick marks (fraction of plot)

xaxs

x-axis style passed to plot

yaxt

y-axis style passed to plot

bty

box type passed to plot

always_show_start

logical indicating whether to show starting model when fit is present

add

logical indicating whether to add to existing plot

ppm_map

sparse axis map created by make_map

Value

No return value, called for side effects (draws a plot).

Examples

spec_file <- system.file("extdata", "tyrosine", "proton.ft1", package = "fitnmr")
spec <- read_nmrpipe(spec_file)

start_resonances <- structure(
  list(
    x = c("HA", "HB3", "HB2", "HD1/2", "HE1/2"),
    x_sc = c(
      "HA-HB3 HA-HB2",
      "HA-HB3 HB3-HB2",
      "HA-HB2 HB3-HB2",
      "HD1/2-HE1/2-3 HD1/2-HE1/2-5",
      "HD1/2-HE1/2-3 HD1/2-HE1/2-5"
    )
  ),
  row.names = c("HA", "HB3", "HB2", "HD1/2", "HE1/2"),
  class = "data.frame"
)

start_nuclei <- structure(
  list(
    omega0_ppm = c(3.364, 2.635, 2.799, 6.94, 6.538),
    r2_hz = c(0.7, 0.7, 0.7, 0.7, 0.7)
  ),
  class = "data.frame",
  row.names = c("HA", "HB3", "HB2", "HD1/2", "HE1/2")
)

start_couplings <- structure(
  list(hz = c(7.153, 5.159, -13.941, 7.7, 2)),
  class = "data.frame",
  row.names = c("HA-HB3", "HA-HB2", "HB3-HB2", "HD1/2-HE1/2-3", "HD1/2-HE1/2-5")
)

start_tables <- list(
  resonances = start_resonances,
  nuclei = start_nuclei,
  couplings = start_couplings
)
param_list <- tables_to_param_list(list(spec), start_tables)
param_list$start_list$m0[] <- 1e9
arg_list <- param_list_to_arg_list(param_list)
fit_input <- do.call(make_fit_input, c(list(list(spec), omega0_plus = 0.075), arg_list))
fit_output <- perform_fit(fit_input)
plot_sparse_1d(fit_output, start_tables)

Plot spectrum from 2D fit

Description

Plot spectrum from 2D fit

Usage

plot_sparse_2d(
  fit_data,
  tables = NULL,
  spec_idx = 1,
  spec_int = NULL,
  col_model = 2,
  col_nucleus = NULL,
  lwd = 1,
  tick_spacing = 0.02,
  coupling_spacing = 0.01,
  coupling_marks = 0.009,
  xaxs = "i",
  yaxs = "i",
  low_frac = 0.05,
  bty = "n",
  always_show_start = FALSE,
  add = FALSE,
  ppm_map_list = NULL
)

Arguments

fit_data

fit_input or fit_output structure

tables

list with resonances, nuclei, and couplings tables

spec_idx

index of spectrum to plot

spec_int

optional matrix to replace the input spectrum intensities

col_model

color for modeled peak shapes

col_nucleus

colors for nuclei

lwd

line width

tick_spacing

spacing between axis ticks (ppm)

coupling_spacing

spacing between coupling annotations (fraction of plot)

coupling_marks

size of coupling tick marks (fraction of plot)

xaxs

x-axis style passed to plot

yaxs

y-axis style passed to plot

low_frac

minimum absolute value (as a fraction of maximum intensity) at which to show contours

bty

box type passed to plot

always_show_start

logical indicating whether to show starting model when fit is present

add

logical indicating whether to add to existing plot

ppm_map_list

optional list of sparse axis maps created by make_map

Value

No return value, called for side effects (draws a plot).

Convert PPM values to points

Description

Convert PPM values to points

Usage

ppm_to_pts(ppm_mat, fheader)

Arguments

ppm_mat

matrix of ppm values

fheader

matrix of generalized ND parameters

Value

A numeric matrix of point indices with the same dimensions as 'ppm_mat', with column names converted from '*_PPM' to '*_AXIS'.

Read an NMRDraw formatted peak table

Description

Read an NMRDraw formatted peak table

Usage

read_nmrdraw_peak_tab(file_path)

Arguments

file_path

path to the NMRDraw peak table file

Value

A 'data.frame' containing the peak table, with columns defined by the 'VARS' line in the NMRDraw file.

Read NMRPipe spectrum

Description

This function reads 1D-4D spectra stored in the NMRPipe format.

Usage

read_nmrpipe(inFormat, dim_order = NULL, complex_data = FALSE)

Arguments

inFormat

character with file name or format for multiple files

dim_order

integer vector used to reorder dimensions or character specifying

complex_data

logical value indicating whether complex data should be read

Details

For three and four dimensional datasets, the spectral data is often spread across multiple files. To read those, inFormat should be a sprintf-style string that describes how the files are named. For instance, if the files are named 001.ft3, 002.ft3, etc., then inFormat should be "%03i.ft3". If there is no zero-padding, as in this case, 0 should be omitted from the format. If there are fewer digits, then the first 3 should be changed accordingly.

The default 2D NMRPipe scripts only have a single transpose ("TP") command, leaving the the indirect dimension as the first dimension in the resulting array. The 2D plotting functions in fitnmr usually plot this first dimension along the x-axis, which will make for generally non-standard contour plots. Furthermore, when peak fitting is employed, this will also be the first dimension. To fix this, you can change the spectral order with the dim_order parameter. The order of the dimensions should be specified in the same way that would be done for aperm. Alternatively, you can specify a character argument to have fitnmr attempt to automatically detect and correct the array order. The only currently supported type is "hx", which will put the dimension with the greatest observe frequency first.

This function is partly based on the pipe2rnmr function from rNMR.

Value

a named list with four elements:

int

multidimensional array with spectrum intensities (ppm values are given in the dimnames)

ppm

list of numeric vectors giving the ppm values associated with each int array dimension

fheader

matrix with dimension-specific header information

header

numeric vector with the complete header contents

The fheader row definitions are as follows (taken from NMRPipe fdatp.h):

Row Name Description
SIZE Number of points in dimension
APOD Current valid time-domain size
SW Sweep Width, Hz
ORIG Axis Origin (Last Point), Hz
OBS Obs Freq, MHz
FTFLAG 1=Freq Domain 0=Time Domain
QUADFLAG Data Type Code (See Below)
UNITS Axis Units Code (See Below)
P0 Zero Order Phase, Degrees
P1 First Order Phase, Degrees
CAR Carrier Position, PPM
CENTER Point Location of Zero Freq
AQSIGN Sign adjustment needed for FT
APODCODE Window function used
APODQ1 Window parameter 1
APODQ2 Window parameter 2
APODQ3 Window parameter 3
C1 Add 1.0 to get First Point Scale
ZF Negative of Zero Fill Size
X1 Extract region origin, if any, pts
XN Extract region endpoint, if any, pts
OFFPPM Additional PPM offset (for alignment)
FTSIZE Size of data when FT performed
TDSIZE Original valid time-domain size
LB Extra Exponential Broadening, Hz
GB Extra Gaussian Broadening, Hz
GOFF Offset for Gaussian Broadening, 0 to 1
OBSMID Original Obs Freq before 0.0ppm adjust

In addition several rows contain information inferred from the header data:

Row Name Description
aq_s Acquisition time, seconds
sw_ppm Original Sweep Width, PPM
direct Direct (1) or indirect (0) dimension
alias Aliasing (0/1) with inversion (-1)
mag Magnitude mode (direct from FDMCFLAG)

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package="fitnmr")
spec <- read_nmrpipe(spec_file, dim_order="hx")
str(spec)

Convert data frame of resonances into a parameter list

Description

Convert data frame of resonances into a parameter list

Usage

resonance_to_param_list(spec, resonance, nuclei, couplings)

Arguments

spec

single spectrum

resonance

data frame with resonances

nuclei

data frame with nuclei chemical shifts and R2 rates

couplings

data frame with scalar couplings

Simulate an FID using the NMRPipe SimTimeND function

Description

Simulate an FID using the NMRPipe SimTimeND function

Usage

sim_time_nd(
  peak_tab,
  fheader,
  rms = 0,
  iseed = stats::runif(1, max = .Machine$integer.max),
  file_path = NULL,
  verbose = FALSE
)

Arguments

peak_tab

NMRDraw peak table

fheader

matrix of generalized ND parameters

rms

RMS noise level

iseed

random seed

file_path

optional output path for the simulated FID

verbose

logical indicating whether to print the command

Value

The integer exit status from 'system2("SimTimeND", ...)' (typically '0' on success).

Combine parameter lists referring to different spectra

Description

Combine parameter lists referring to different spectra

Usage

spec_bind(...)

Arguments

...

any number of parameter lists or a single list of parameter lists

Determine a matrix of fractional peak overlap

Description

Determine a matrix of fractional peak overlap

Usage

spec_overlap_mat(peak_int_list)

Arguments

peak_int_list

list of peak intensity arrays

Split string of scalar coupling names

Description

The only currently implemented way of splitting string is using whitespace

Usage

split_coupling_names(name_char)

Arguments

name_char

single string (character vector of length 1) with scalar coupling names

Convert tables with resonance/nuclei/couplings to a parameter list

Description

Convert tables with resonance/nuclei/couplings to a parameter list

Usage

tables_to_param_list(spec_list, tables)

Arguments

spec_list

list of spectra

tables

list with resonance/nuclei/couplings tables

Value

A parameter 'list' containing 'start_list', 'group_list', 'comb_list', and associated naming vectors used by fitting functions.

Examples

spec_file <- system.file("extdata", "tyrosine", "proton.ft1", package = "fitnmr")
spec <- read_nmrpipe(spec_file)

start_resonances <- structure(
  list(
    x = c("HA", "HB3", "HB2", "HD1/2", "HE1/2"),
    x_sc = c(
      "HA-HB3 HA-HB2",
      "HA-HB3 HB3-HB2",
      "HA-HB2 HB3-HB2",
      "HD1/2-HE1/2-3 HD1/2-HE1/2-5",
      "HD1/2-HE1/2-3 HD1/2-HE1/2-5"
    )
  ),
  row.names = c("HA", "HB3", "HB2", "HD1/2", "HE1/2"),
  class = "data.frame"
)

start_nuclei <- structure(
  list(
    omega0_ppm = c(3.364, 2.635, 2.799, 6.94, 6.538),
    r2_hz = c(0.7, 0.7, 0.7, 0.7, 0.7)
  ),
  class = "data.frame",
  row.names = c("HA", "HB3", "HB2", "HD1/2", "HE1/2")
)

start_couplings <- structure(
  list(hz = c(7.153, 5.159, -13.941, 7.7, 2)),
  class = "data.frame",
  row.names = c("HA-HB3", "HA-HB2", "HB3-HB2", "HD1/2-HE1/2-3", "HD1/2-HE1/2-5")
)

start_tables <- list(
  resonances = start_resonances,
  nuclei = start_nuclei,
  couplings = start_couplings
)
param_list <- tables_to_param_list(list(spec), start_tables)
param_list$start_list$m0[] <- 1e9
arg_list <- param_list_to_arg_list(param_list)
fit_input <- do.call(make_fit_input, c(list(list(spec), omega0_plus = 0.075), arg_list))
fit_output <- perform_fit(fit_input)

Update bounds on fitting parameters

Description

Update bounds on fitting parameters

Usage

update_fit_bounds(
  fit_input,
  omega0_r2_factor = NULL,
  r2_bounds = NULL,
  sc_bounds = NULL
)

Arguments

fit_input

fit_input structure

omega0_r2_factor

optional factor for omega0 bounds based on r2

r2_bounds

optional numeric vector of length 2

sc_bounds

optional numeric vector of length 2

Value

A modified 'fit_input' list with updated parameter bounds.

Examples

spec_file <- system.file("extdata", "t1", "1.ft2", package = "fitnmr")
spec <- read_nmrpipe(spec_file, dim_order = "hx")
fit_input <- make_fit_input(
  list(spec),
  omega0_start = matrix(c(8.5400, 119.76), nrow = 2),
  omega0_plus = c(0.075, 0.75),
  r2_start = 4,
  m0_start = 1e9
)
fit_input <- update_fit_bounds(fit_input, omega0_r2_factor=1.5, r2_bounds=c(0.5, 20))

Convert widths in Hz into points

Description

Convert widths in Hz into points

Usage

whz_to_pts(whz_mat, fheader)

Arguments

whz_mat

matrix of widths in Hz

fheader

matrix of generalized ND parameters

Write an NMRDraw formatted peak table

Description

Write an NMRDraw formatted peak table

Usage

write_nmrdraw_peak_tab(peak_tab, file_path)

Arguments

peak_tab

data frame containing peak table data

file_path

path to write the NMRDraw peak table file

Value

No return value, called for side effects (writes 'file_path').