Name: PGCONT
Purpose: contour map of a 2D data array (contour-following)
Category: GRAPHICS
File: pgplot.src
Author: T.J. Pearson
Use: see description below.
Description:
SUBROUTINE PGCONT (A, IDIM, JDIM, I1, I2, J1, J2, C, NC, TR)
INTEGER IDIM, JDIM, I1, J1, I2, J2, NC
REAL A(IDIM,JDIM), C(*), TR(6)
Draw a contour map of an array. The map is truncated if
necessary at the boundaries of the viewport. Each contour line
is drawn with the current line attributes (color index, style, and
width); except that if argument NC is positive (see below), the line
style is set by PGCONT to 1 (solid) for positive contours or 2
(dashed) for negative contours.
Arguments:
A (input) : data array.
IDIM (input) : first dimension of A.
JDIM (input) : second dimension of A.
I1, I2 (input) : range of first index to be contoured (inclusive).
J1, J2 (input) : range of second index to be contoured (inclusive).
C (input) : array of NC contour levels; dimension at least NC.
NC (input) : +/- number of contour levels (less than or equal
to dimension of C). If NC is positive, it is the
number of contour levels, and the line-style is
chosen automatically as described above. If NC is
negative, it is minus the number of contour
levels, and the current setting of line-style is
used for all the contours.
TR (input) : array defining a transformation between the I,J
grid of the array and the world coordinates.
The world coordinates of the array point A(I,J)
are given by:
X = TR(1) + TR(2)*I + TR(3)*J
Y = TR(4) + TR(5)*I + TR(6)*J
Usually TR(3) and TR(5) are zero - unless the
coordinate transformation involves a rotation or
shear.
Updates: Oct 16, 1998: JPT automatically extracted from source.