metabodecon (version 1.6.2)

draw_spectrum: Draw Spectrum

Description

Draws a single spectrum. Internally used by plot_spectrum(), which is usually the recommended way to plot spectra. For usage examples see test/testthat/test-draw_spectrum.R.

Usage

draw_spectrum(
  obj,
  foc_rgn = NULL,
  foc_frac = NULL,
  foc_only = TRUE,
  add = FALSE,
  fig_rgn = NULL,
  main = NULL,
  show = TRUE,
  show_d2 = FALSE,
  truepar = NULL,
  mar = c(4.1, 5.1, 1.1, 1.1),
  sf_vert = "auto",
  si_line = list(),
  sm_line = list(),
  sp_line = list(),
  d2_line = list(),
  al_line = list(),
  lc_lines = list(),
  tp_lines = list(),
  al_lines = list(),
  cent_pts = list(),
  bord_pts = list(),
  norm_pts = list(),
  bg_rect = list(),
  foc_rect = list(),
  lc_rects = list(),
  tp_rects = list(),
  bt_axis = list(),
  lt_axis = list(),
  tp_axis = list(),
  rt_axis = list(),
  bt_text = list(),
  lt_text = list(),
  tp_text = list(),
  rt_text = list(),
  tp_verts = list(),
  lc_verts = list(),
  al_verts = list(),
  ze_hline = list(),
  al_arrows = list(),
  lgd = list()
)

Value

NULL. Called for side effect of plotting.

Arguments

obj

An object of type spectrum or decon2. For details see Metabodecon Classes.

foc_rgn

Numeric vector specifying the start and end of focus region in ppm.

foc_frac

Numeric vector specifying the start and end of focus region as fraction of the full spectrum width.

foc_only

Logical. If TRUE, only the focused region is drawn. If FALSE, the full spectrum is drawn.

add

If TRUE, draw into the currently open figure. If FALSE, start a new figure.

fig_rgn

Drawing region in normalized device coordinates as vector of the form c(x1, x2, y1, y2).

main

Main title of the plot. Drawn via title().

show

Logical. If FALSE, the function returns without doing anything.

show_d2

Logical. If TRUE, the second derivative of the spectrum is drawn. Setting this to TRUE changes most of the defaults for the drawing, e.g. by disabling the drawing of anything related to signal intensities and by changing the y-axis label to "Second Derivative".

truepar

Data frame with columns x0, A and lambda containing the true lorentzian that were used to simulate the spectrum. Required if any tp_* argument is set.

mar

Number of lines below/left-of/above/right-of plot region.

sf_vert

Scale factor for vertical lines corresponding to lc_verts, tp_verts and al_verts. If a numeric value is provided, the height of each line equals the area of the corresponding lorentzian curve multiplied by sf_vert. In addition, the following strings are supported:

• "auto": A suitable numeric value for sf_vert is chosen automatically, in a way that the highest integral equals the highest signal intensity after multiplication with sf_vert.

• "peak": Vertical lines are drawn from bottom to top of the corresponding peak.

• "full": Vertical lines are drawn over the full vertical range of the plot region.

si_line, sm_line, sp_line, al_line, d2_line, lc_lines, tp_lines, al_lines

List of parameters passed to lines() when drawing the raw signal intensities (si_line), smoothed signal intensities (sm_line), superposition of lorentzian curves (sp_line), aligned lorentzian curves (al_line), second derivative (d2_line), lorentzian curves found by deconvolution (lc_lines), true lorentzian curves (tp_lines) and aligned lorentzian curves (al_lines), respectively.

cent_pts, bord_pts, norm_pts

List of parameters passed to points() when drawing the peak center points, peak border points and non-peak points.

bg_rect, lc_rects, foc_rect, tp_rects

List of parameters passed to rect() when drawing the background, lorentzian curve substitutes, focus rectangle and/or true lorentzian curve substitutes.

bt_axis, lt_axis, tp_axis, rt_axis

List of parameters used to overwrite the default values passed to axis() when drawing the bottom, left, top and right axis. In addition to the parameters of axis(), the following additional parameters are supported as well:

• n: Number of tickmarks.

• digits: Number of digits for rounding the labels. If a vector of numbers is provided, all numbers are tried, until n unique labels are found. See 'Details'.

• sf: Scaling factor. Axis values are divided by this number before the labels are calculated. If you set this to anything unequal 1, you should also set the corresponding margin text in a way that reflects the scaling. Example: by default, a scaling factor of 1e6 is used for drawing signal intensities and a scaling factor of 1 for drawing the second derivative. To make clear, that the user should be careful when interpreting the signal intensity values, the corresponding margin text is set to "Signal Intensity [au]" where "au" means "Arbitrary Units", indicating that the values might be scaled.

bt_text, lt_text, tp_text, rt_text

List of parameters used to overwrite the default values passed to mtext() when drawing the bottom, left, top and right margin texts (i.e. the axis labels).

lc_verts, tp_verts, al_verts

List of parameters passed to segments() when drawing vertical lines at the centers of estimated, true or aligned lorentzian curves. Setting tp_verts$show to TRUE requires truepar to be set.

ze_hline

List of parameters passed to abline() when drawing a horizontal line at y = 0.

al_arrows

List of parameters passed to arrows() when drawing arrows between the estimated and aligned lorentzian curve centers.

lgd

List of parameters passed to legend() when drawing the legend.

Author

2024-2025 Tobias Schmidt: initial version.

Details

Parameters bt_axis, lt_axis, tp_axis and rt_axis all support option n and digits, where n = 5 means "Draw 5 tickmarks over the full axis range" and digits = 3 means "round the label shown beside each tickmark to 3 digits". If n or digits is omitted, a suitable value is chosen automatically. Providing a vector of digits causes each digit to be tried until a digit is encountered that results in n unique labels. Example:

Assume we have n = 4 and the corresponding calculated tickmark positions are: 1.02421, 1.02542, 1.02663 and 1.02784. If we provide digits = 1:5, the following representations are tried:

digit	label 1	label 2	label 3	label 4
1	1.0	1.0	1.0	1.0
2	1.02	1.03	1.03	1.03
3	1.024	1.025	1.027	1.028
4	1.0242	1.0254	1.0266	1.0278
5	1.02421	1.02542	1.02663	1.02784

In the above example the process would stop at digit = 3, because at this point we have n = 4 unique labels (1.024, 1.025, 1.027 and 1.028).

Examples

decon <- deconvolute(sim[[1]], sfr = c(3.55, 3.35))
draw_spectrum(obj = decon)
draw_spectrum(obj = decon, lgd = list(x = "top", bg = NA))
draw_spectrum(obj = decon, foc_rgn = c(3.45, 3.37))
draw_spectrum(obj = decon, add = FALSE, lgd = FALSE,
              fig = c(.2, .8, .2, .4), mar = c( 0,  0,  0,  0))
draw_spectrum(obj = decon, add = TRUE, lgd = FALSE,
              fig = c(0.2, 0.8, 0.6, 0.8), mar = c(0, 0, 0, 0))
draw_spectrum(obj = decon, lc_lines = NULL, lc_rects = NULL, foc_only = FALSE)