NAME

       Histogram_params - This document briefly describes all histogram internal parameters.  The
       Histogram utility has four parameter setting routines: HSTOPC sets parameters of type
       CHARACTER; HSTOPI sets parameters of type INTEGER; HSTOPL sets parameters of type LOGICAL;
       HSTOPR sets parameters of type REAL.

DESCRIPTION

       Parameters of type CHARACTER set in calls to entry HSTOPC:

       FOR         Format for class labels.  Default is ´(G10.3)´.

       TIT         A main title of up to 96 characters.  Only 45 characters are written per line
                   so up to 3 lines may be written.  The default is no title.

       LAB         A label for the class interval (histogram bar) axis.  Default value is ´CLASS
                   INTERVALS´ when the HSTOPL option ´MID=OFF´ is selected, and ´CLASS MIDVALUES´
                   when ´MID=ON´.

       PTI         The percent axis label.  Default value when ´PTI=OFF´ is ´PERCENT OCCURRENCE´
                   when IFLAG = 0, or 1, and ´PERCENT of MAXIMUM´ when IFLAG = 2, or 3.

       FQN         The frequency axis label.  Default value is ´FREQUENCY´.

       CHR         A concatenated string of class interval labels.  Default is that class labels
                   will be internally computed numeric values (real or integer.)

Parameters of type INTEGER set in calls to entry HSTOPI:

       COL         Eight components of the graphic can be assigned colors.  Default is that all
                   components of the graphic are assigned the color white (background color
                   black.)

       CLA         Allows the size and orientation of class labels to be altered.  Defaults are
                   medium sized characters with a horizontal alignment.

Parameters of type LOGICAL set in calls to entry HSTOPL:

       HOR         Defines whether histogram bars will be draw horizontally or vertically.
                   Default is vertical bars.

       PER         Determines whether a percentage axis is drawn as a second axis on the opposite
                   side of the frame from the normal frequency axis.  Default is a second axis.

       MID         Determines if class labels are placed at the midpoint of each class interval,
                   or if the class interval end points are labeled.  Default is labels at the
                   midpoints.

       SHA         Determines whether histogram bars are to be shaded.  Default is shaded bars.

                   Devices will vary as to how they interpret shading.

       DRL         Determines if lines are to be drawn through the histogram bars where Y-axis
                   tick marks would occur.  Default is no line.

       MED         Determines if a line is drawn through the median value of all points.  Default
                   is no median line.

       NMV         Determines if missing values are to be subtracted from the number of input
                   points before bin percentages are computed.  The default is to subtract out
                   the missing values.  HSTOPR option MVA must be ON to activate this option.

       PMV         Determines if the number of input points and the number of missing values are
                   to be printed on the plot.  The default is to not print.  HSTOPR option MVA
                   must be ON to activate this option.

       PRM         Determines if a perimeter is to be drawn around the histogram.  Default is no
                   perimeter.

       FRA         Determines whether the frame is advanced after the histogram is drawn.
                   Default is a frame advance.

       LIS         Determines if all the options along with their values are to be printed on the
                   standard output.  Default is no printed output.

       DEF         A global default switch which allows all parameters to be returned to their
                   default states in one call.  All parameters begin at their default values.

Parameters of type REAL set in calls to entry HSTOPR:

       WIN         Defines a rectangular region of the total frame in NDC´s where the current
                   histogram is to be plotted.  For example, XMIN=0., XMAX=.5, YMIN=.5, and
                   YMAX=1.  would specify the upper left quadrant of the frame.  Default is the
                   total frame is used.

       SPA         Defines the amount of spacing between histogram bars and and the amount of
                   overlap of histogram bars.  Default values: spacing = 2.0, overlap = -1.0 This
                   will yield spacing between bars on a single histogram and overlap of bars in
                   the comparison of two histograms.

       MVA         Defines a special value which can be inserted in the data stream to indicate
                   that the true data value is missing, and a testing tolerance which allows the
                   special values to be detected.  See also parameters PMV, and NMV.  Default
                   values: special value = -9999., tolerance = 1.E-10.

SEE ALSO

       Online: histogram, histgr, hstopc, hstopi, hstopl, hstopr, ncarg_cbind

       Hardcopy: NCAR Graphics Fundamentals, UNIX Version

COPYRIGHT

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research

       The use of this Software is governed by a License Agreement.