HAFTON(3NCARG) | NCAR GRAPHICS | HAFTON(3NCARG) |
HAFTON - draws a half-tone picture from data stored in a rectangular array with the intensity in the picture proportional to the data value.
This routine is part of the Halftone utility in NCAR Graphics. To see the overview man page for this utility, type "man halftone".
HAFTON is obsolete. It has been replaced by the CPCICA entry of the Conpack contouring package.
HAFTON continues to be provided for compatibility of early NCAR Graphics codes. If you are writing new code, we suggest that you use CPCICA.
CALL HAFTON (Z,L,M,N,FLO,HI,NLEV,NOPT,NPRM,ISPV,SPVAL)
NOPT positive yields direct mapping. The largest value of Z produces the most dense dots. On mechanical plotters, large values of Z will produce a dark area on the paper. With the film development methods used at NCAR, large values of Z will produce many (white) dots on the film, also resulting in a dark area on reader-printer paper.
NOPT negative yields inverse mapping. The smallest values of Z produce the most dense dots resulting in dark areas on the paper.
The absolute value of NOPT determines the mapping of Z onto the intensities. For IABS(NOPT)
= 0 The mapping is linear. For
each intensity there is an equal
range in Z value.
= 1 The mapping is linear. For
each intensity there is an equal
range in Z value.
= 2 The mapping is exponential. For
larger values of Z, there is a
larger difference in intensity for
relatively close values of Z. Details
in the larger values of Z are displayed
at the expense of the smaller values
of Z.
= 3 The mapping is logarithmic, so
details of smaller values of Z are show
at the expense of larger values of Z.
= 4 Sinusoidal mapping, so mid-range values
of Z show details at the expense of
extreme values of Z.
= 5 Arcsine mapping, so extreme values of
Z are shown at the expense of mid-range
NPRM=0: The perimeter is drawn with ticks pointing at data locations. (Side lengths are proportional to number of data values.)
NPRM positive: No perimeter is drawn. The picture fills the frame.
NPRM negative: The picture is within the confines of the user's current viewport setting.
ISPV = 0: Special value feature not in use. SPVAL is ignored.
ISPV non-zero: Special value feature in use. SPVAL defines the special value. Where Z contains the special value, no half-tone is drawn. If ISPV
= 0 Special value feature not in use.
SPVAL is ignored.
= 1 Nothing is drawn in special value
area.
= 2 Contiguous special value areas are
surrounded by a polygonal line.
= 3 Special value areas are filled
with X(s).
= 4 Special value areas are filled in
with the highest intensity.
To use HAFTON, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order.
Online: halftone, ezhftn, halftone_params, conpack, conpack_params, cpcica
Hardcopy: NCAR Graphics Contouring and Mapping Tutorial; NCAR Graphics Fundamentals, UNIX Version; User's Guide for NCAR GKS-0A Graphics
Copyright (C) 1987-2009
University Corporation for Atmospheric Research
The use of this Software is governed by a License Agreement.
March 1993 | UNIX |