DMASS procedure
Plots discrete data like mass spectra, discrete probability functions (J.W. McNicol).
Options
Parameters
Description
DMASS produces plots appropriate for ordered discrete data such as mass spectra, discrete probability functions or principal component weights. The Y parameter specifies one or more variates, each of which defines the heights of a set of vertical lines. By default the lines are plotted at equal unit spacing along the x-axis (i.e. at positions 1, 2 and so on), but other positions can be specified using the X option. The X and Y variates must all have equal lengths. So, for example, if a particular line is absent for one of the spectra, the variate must contain a zero value. The LINECOLOUR parameter defines the colour to be used for each set. By default, the colours 1, 2 and so on are used in turn.
As usual, options TITLE, WINDOW and SCREEN allow you to define a title for the plot, specify which window to use, and indicate whether or not to clear the screen beforehand. Likewise, options YTITLE, XTITLE, YMARKS, XMARKS, YMPOSITION, XMPOSITION, YLABELS and XLABELS define titles, tick marks and labelling of the axes, as in the AXES directive. The pens to use for the title and for the axes can be defined by the PENTITLE and PENAXES options, and the LINETHICKNESS option controls the thickness of the lines used to plot the masses.
Options: X, TITLE, WINDOW, YTITLE, XTITLE, YMARKS, XMARKS, YMPOSITION, XMPOSITION, YLABELS, XLABELS, PENTITLE, PENAXES, LINETHICKNESS, SCREEN.
Parameters: Y, LINECOLOUR.
Method
For the ith mass, a pair of variates of length 2 is created; y=[mass,0] and x=[i,i]. These are plotted by the DGRAPH directive with METHOD=line.
Action with
RESTRICT
DMASS takes account of restrictions on X or any of the Y variates.