                 Chapter 16: Quick Plots

This chapter presents some quick plots that are  collections
of DISLIN routines  for displaying  data with one statement.
Axis scaling  is done automatically, but can be set manually
with the routine  QPLSCL.  By default,  graphical  output is
sent to the screen. 

16.1 Plotting Curves

                        Q P L O T

QPLOT connects data points with lines.

The call is:  CALL QPLOT (XRAY, YRAY, N)          level 0, 1

XRAY, YRAY    are arrays that contain X- and Y-coordinates.
N             is the number of data points.

                        Q P L C R V

QPLCRV is a similar routine to  QPLOT,  but can display mul-
tiple curves.

The call is:  CALL QPLCRV (XRAY, YRAY, N, COPT)   level 0, 1

XRAY, YRAY    are arrays that contain X- and Y-coordinates.
N             is the number of data points.
COPT          is a character string that describes the mean-
              ing of the  curve.  COPT can  have  the values
              'FIRST', 'NEXT' and 'LAST'.
              
16.2 Scatter Plots

                        Q P L S C A

QPLSCA marks data points with symbols.

The call is:  CALL QPLSCA (XRAY, YRAY, N)          level 0, 1

XRAY, YRAY    are arrays that contain X- and Y-coordinates.
N             is the number of data points.

16.3 Bar Graphs

                        Q P L B A R

QPLBAR plots a bar graph.

The call is:  CALL QPLBAR (XRAY, N)                level 0, 1

XRAY          is an  array containing data points.
N             is the number of data points.

16.4 Pie Charts

                        Q P L P I E

QPLPIE plots a pie chart.

The call is:  CALL QPLPIE (XRAY, N)                level 0, 1

XRAY          is an  array containing data points.
N             is the number of data points.

16.5 3-D Colour Plots

                        Q P L C L R

QPLCLR makes a 3-D colour plot of a matrix.

The call is:  CALL QPLCLR (ZMAT, IXDIM, IYDIM)     level 0, 1

ZMAT          is a matrix  with the dimension  (IXDIM, IYDIM)
              containing the function values.
IXDIM, IYDIM  are the dimensions of ZMAT.

16.6 Surface Plots

                        Q P L S U R

QPLSUR makes a surface plot of a matrix.

The call is:  CALL QPLSUR (ZMAT, IXDIM, IYDIM)     level 0, 1

ZMAT          is a matrix  with the dimension  (IXDIM, IYDIM)
              containing the function values.
IXDIM, IYDIM  are the dimensions of ZMAT.

16.7 Contour Plots

                        Q P L C O N

QPLCON makes a contour plot of a matrix.

The call is:  CALL QPLCON (ZMAT, IXDIM, IYDIM, NLEV) 
                                                   level 0, 1

ZMAT          is a matrix  with the dimension  (IXDIM, IYDIM)
              containing the function values.
IXDIM, IYDIM  are the dimensions of ZMAT.
NLEV          is the number of contour levels  that should be
              generated.

16.8 Setting Parameters for Quick Plots

Quick plots can be called in level 0 and level 1  of  DISLIN.
If they are called in level 0,  the statements  CALL METAFL (
'CONS') and  CALL DISINI are executed by quick plots. If they
are called in level 1,  these statements  will be suppressed.
This  means that  programs  can change  the output  device of 
quick plots and  define  axis names  and titles  if they call
quick plots in level 1 after a call to DISINI.

                        Q P L S C L

QPLSCL overwrites the automatic scaling of quick plots.

The call is:  CALL QPLSCL (A, E, OR, STEP, CAX)    level 0, 1

A, E          are the lower and upper limits  of the axis.
OR, STEP      are the first axis label  and the  step between
              labels.
CAX           is a character string that defines the axes. 
              CAX can contain the characters 'X', 'Y' and 'Z'.


The  following  example  defines axis  names  and a title for
QPLOT:

                   CALL METAFL ('CONS')
                   CALL DISINI

                   CALL NAME ('X-axis', 'X')
                   CALL NAME ('Y-axis', 'Y')
                   CALL TITLIN ('This is a Title', 2)
                   CALL QPLOT (XRAY, YRAY, N)
                   END
