Help for QPLOT2

PURPOSE:  
    QPLOT2 plots the DN values along a specified straight line through
  an image.  It also does spectral plots for multi-channel data. 

OPERATION:

   QPLOT2 operates on single or multiple single-band BSQ imgages in
   BYTE, HALF, FULL or REAL format. For FULL and REAL formats the DN 
   ranges are internally limited to -65536 to +65535 DN ranges. It does
   work for multi-band BSQ (MSS) images.

   Plots for up to 10 input image files are allowed for Single Band images.
   and up to 50 lines (profiles) for each image is allowed. The straight lines
   may be oriented in any direction, horizontal, vertical or at a slant.

   Modes are distinguished via the PROCESS and SPROCESS parameters. 

   PROCESS parameter is used for One band BSQ files
   SPROCESS parameter is used for multiple BSQ files.
   These parameters are mutually exclusive

    
PARAMETERS:

  There are two types of parameters:

  (1) Parameters with a single specification:
        INP         NCHAN
        TITLE       LOTITLE     XTITLE
        YTITLE      LABELSIZ    LOLABEL
        NORM        RDS         DISPLACE
        XLENGTH     YLENGTH
        XSCALE      YSCALE

  (2) Parameters which have a specification for each line plotted:
        PROCESS     SPROCESS
        XVALUES     YVALUES

  The parameter PROCESS specifies that one or more lines to be plotted. 
  Following the keyword, each plot is specified by a set of five numbers.
  The first value in each quintet specifies the Input Data Set Number and
  the remaining four values specify the Starting Line, Starting Sample,
  Ending Line, and Ending Sample. (No Default).

  NOTE:  The line plotted will cover SQRT((EL-SL)**2+(ES-SS)**2) "relative 
  samples"  along the horizontal axis and will start at "relative sample" 1.

  This version allows plots for BYTE, HALF, FULL or REAL data files.
  It also allows for mixed filetypes in INP to be plotted on same graph.

  The SPROCESS parameter for spectral data only uses 2 numbers, the
  line and sample position of a single point within the MSS formatted image.
  Up to 20 points can be specified. Thus, it is possible to look at
  a 20 point straight line in an image or 20 widely separated points.

  You can use PROCESS for an MSS image but you will only get a profile
  on the 1st MSS Band.

  The parameters TITLE, XTITLE and YTITLE refer to the usual plot labelling
  schemes.

  The LABELSIZ parameter refers to the font size in points for all the text in the
  graph. This is suitable for changes of XLENGTH and YLENGTH when different 
  from the default. Note, the internal font is Ariel and cannot be changed.
  The label data superimposed on graph is always 9-point Ariel.

  XSCALE and YSCALE are the max size of the X plot values and Y plot values.

  The parameter NORM is used to normalize the DN values to 1. The
  DN values are ratioed to the max DN of the line. Especially useful
  when different data formats occur for each input image.

  XLENGTH and YLENGTH tell gnuplot what size the output is in inches
  at 72 dots/inch. Default is 7 inches wide by 5 inches long,
  or 648 by 504 pixels.

  The parameter TICS refers to placing crosshatching on the plot along
  with the axis tic marks which are in units of 10.

  The parameter RDS causes DN values to be scaled by the following equation:
               OUT=SQRT(IN**2-RDS**2).
  Where RDS is the value in the RDS parameter.
 
  For plots containing multiple lines, the parameter DISPLACE forces 
  each line to be displaced successively by the DISPLACE=DN on the
  It does not work on plots containing a single line. 


  LOTITILE and LOLABEL keywords are no longer supported (gnuplot).

  
NOTES:

  The common plotting routines used in MIPL were removed in this version
  and converted to gnuplot commands. The Mipl version in 2011 uses the
  xrt commercial plotting package.


OUTPUTS:

  Up to two types of outputs can be produced, interactive plots using 
  gnuplot and hardcopy plots suitable for publications using gnuplot and ghostscript
  or gimp.

  The first type of plot is rendered via the creation of a gnuplot instruction, or
  command file. This is indicated by the file extension of .gpi.  After completion
  of the qplot2 task this file creates an interactive plot on the desktop, e.g.,
     ush gnuplot qplot.gpi.
  This display stays active until mouse-clicked somewhere on the plot panel.
  The terminal window prompt is inactive until the panel is closed.

  If you wish, you can issue the following gnuplot command to keep the plot on
  the desktop.

  ush gnuplot -persist gplot.gpi

  Again the terminal prompt is inactive until the plot panel has been mouse-clicked.
  After the mouse click the panel remains but the terminal prompt is restored. This
  makes it easy to compare outputs from several qplot2 commands.

  A second output is derived from the PLOTOUT parameter. By default this parameter is
  set to "NONE" so no hardcopy output is produced.  It can be set to "YES" in which
  case a file called gplot2.gpi is created. If you issue the command

  ush gnuplot qplot2.gpi 
 
  no interactive plot panel is created but it produces a file qplot.eps. This
  file can be displayed using ghostscript (the usual unix command is gs).

  gs qplot2.eps

  or gimp, e.g.,

  gimp qplot2.eps

  PLOTOUT can also be given a file name, e.g.,
  PLOTOUT=fourbands   (not necessary to give file extension) 

  In that case the 2 outputs are produced, fourbands.gpi and fourbands2.gpi.
  Fourbands.gpi gives the interactive gnuplot panel and the second one, when
  run, will create fourbands.eps which can be displayed by ghostscript or gimp.


RESTRICTIONS:

  (1) Maximum number of lines plotted is 10.
  (2) Spectral plots require the SPROCESS parameter.
  (3) Cannot use PROCESS and SPROCESS parameters simultaneously
  (4) Spectral plots on multiple files are not supported
  (5) Maximum of 10 input files

Note:  This program makes use of multiple intermediate data sets.
  If this program is run under a directory which does not allow the
  creation of these files either because of disk quotas or protection)
  the program will die and plot file will not be created.



HISTORY:

  Original Programmer:  John H. Reimer,  22 Aug. 1982
  Cognizant Programmer:  Ray Bambery   

  Revisions:
  1985-04-22 John H. Reimer - Converted to Vicar2
  1995-07-10 C. Randy Schenk (CRI) - Ported to Unix (MSTP S/W Conversion)
  2011-06-13 Ray Bambery - Converted to use gnuplot, and work
             under gfortran 4.4.4 on liunx
  2012-06-05 Ray Bambery - fixed dimensions of x,y in subroutine equiv
  2012-07-10 Ray Bambery - Renamed qplot2g for delivery to MIPL
             qplot2 still uses XRT/Graph package, 
             Removed <tab> in front of continuation
             lines to make backward compatible with
             32-bit Linux gfortran 4.2.1, otherwise
             compatible 64-bit Linux gfortran 4.6.3</tab>
  2012-10-13 Ray Bambery - Renamed back to qplot2, in agreement
             with Lucas Kamp of mipl. The XRT graph package
             is to be removed from mipl. XRT was never used by
             cartlab. Implemented LABELSIZ parameter
  2013-07-09 Ray Bambery - Fixed truncated plot labeling
             created unique names for data sets for plots to
             prevent confusion in long scripts. Added PLOTFMT
  2013-07-12 Ray Bambery - Adjusted eps format to more readable fonts
  2013-08-21 Ray Bambery - Fixed grid, notics code in gpi output. Fixed
             DISPLACE parmeter, Changed mode of placing labels
             on plots from proportional to character mode. 
             Added filenames to plot
  2013-08-28 Ray Bambery - Added NOLABEL parameter to inhibit overprinting
             of VICAR labels on graph (Sometimes way too many labels)
             It can corrupt the gnuplot script which will give an
             error like "line 54: invalid expression"
             on entering the command gnuplot xx.gpi                        
  2015-08-19 Walt Bunch - Fixed end of line encoding so linux and sun
                will yield same output.