LSPLOT-Hardcopy spectrum plot of specified size (up to 3 metres)

Description:

LSPLOT produces a splot of a spectrum, usually on a hard copy device, with a physical size that can be specified (in metres) by the user. The device used is that specified by the HARD command. It will allow plots up to the maximum size allowed by the GKS driver being used - in some cases this means that a non-standard device name must be specified in order to allow a larger maximum size than usual. LSPLOT is very similar to SPLOT, except that it has plot dimension parameters and does not support build plots.

Parameters:

SPECTRUM

The name of the spectrum to be plotted by LSPLOT. It should be a 1-dimensional array.

XSIZE

The length of the plot in metres. LSPLOT can produce plots up to 10 metres in length.

YSIZE

The height of the plot in metres. The reset value is the full page height for the device.

WHOLE

If set, the whole of the spectrum is plotted. Otherwise, the limits plotted are determined by the values of XSTART and XEND, which you will be prompted for if they were not specified in the command string.

AUTOSCALE

If set, the plot is scaled so that all of the data to be plotted just fits on the display. Otherwise, the scale of the plot is determined by the values of HIGH and LOW, which you will be prompted for if they were not specified in the command string.

XSTART

Specifies the first X value to be plotted, in the units used by the data - angstroms, for example, if the data is wavelength calibrated. XSTART can be set before the start of the data, if necessary. RESET will set XSTART to the first X value in the data.

XEND

Specifies the last X value to be plotted, in the units used by the data - angstroms, for example, if the data is wavelength calibrated. XEND can be set after the end of the data, if necessary. RESET will set XEND to the last X value in the data.

HIGH

The maximum data value to be plotted - i.e. the top Y axis value for the plot.

LOW

The minimum data value to be plotted - i.e. the bottom Y axis value for the plot.

BIAS

A bias value applied to the data, usually to bias up a plot which is to be superimposed upon a previous plot of almost identical data values. This makes the comparison easier. BIAS N is essentially equivalent to setting HIGH and LOW down by an amount N, so can result in unexpected axis values.

LABEL

The label that will appear at the top of the plot.

LINES

Specifies that the plot is to made as a 'point-plot', in a 'join the dots' fashion. The alternative is a histogram plot. LINES will usually be a little faster, but messier, because the resolution of the plotting device may result in stepped lines.

Source comments:

 L S P L O T    /    E L S P L O T

 These are versions of SPLOT and ESPLOT that allow the size of
 the plot to be specified.  LSPLOT produces a plot of a single
 spectrum, while ESPLOT produces an error bar plot of a spectrum
 which has error information.

 Command parameters -

 XSIZE       The size of the plot in X, in metres.
 YSIZE       The size of the plot in Y, in metres.
 SPECTRUM    The data to be plotted.  If there
             is an x-axis data component this will be used to
             give the x-axis.  If not, the x-axis will just
             have to be the numbers from 1 to n.
 XSTART      The x-value at which plotting is to start.
 XEND        The x-value at which plotting is to end.
             (XSTART and XEND are not required if the
             WHOLE keyword is set.)
 HIGH        The maximum value to be used for the plot.
 LOW         The minimum value to be used for the plot.
 BIAS        A value used to displace the plot - BIAS is
             effectively a value added to the data before
             it is plotted. (It is implemented as a value
             subtracted from both HIGH and LOW.)
             (HIGH,LOW and BIAS are not required if the
             AUTOSCALE keyword is set.)
 LABEL       A label for the plot.

 Command keywords -

 AUTOSCALE   The program is to work out the values for HIGH
             and LOW, using the maximum and minimum values
             in the data over the specified range.
 WHOLE       The program is to display all of the spectrum.
 LINES       The plot is not done as a histogram, but as
             a 'join the dots' line plot.  (LSPLOT only)

 User variables used:

 HARD        (Character) The device used for HARD plots.

 Note:

 The original version of LSPLOT used GKS 6.2 and the DIAGRAM
 package.  This has now been discontinued, and some of the
 functionality of DIAGRAM (the ability to specify the size of
 the plot in physical units) has appeared in PGPLOT.  This new
 version uses PGPLOT.  It can produce a plot of the specified
 size, BUT only if that size is SMALLER than the default size
 for the device.  In practice, this means that it can only work
 in the way it was intended with `unusual' devices that have
 particularly large default plot sizes (which often need to be set
 up specially for the purpose).
                                     KS / AAO 30th Jan 1984