Function: PGCOTIC
Purpose: Contour map of a 2D data array, with blanking and ticks.
Category: GRAPHICS
File: pgplot.src
Author: M. Vogelaar
Use: CALL PGCOTIC(A , Input REAL ARRAY (2d)
IDIM , Input INTEGER
JDIM , Input INTEGER
I1 , Input INTEGER
I2 , Input INTEGER
J1 , Input INTEGER
J2 , Input INTEGER
C , Input REAL ARRAY
NC , Input INTEGER
TR , Input REAL ARRAY
BLANK, Input REAL
TLEN, Input REAL
TSTEP ) Input INTEGER
A Data array.
IDIM First dimension of A.
JDIM Second dimension of A.
I1 Start of range of first index to be
contoured (inclusive).
I2 End of range of first index to be contoured
(inclusive).
J1 Start of range of second index to be
contoured (inclusive).
J2 End of range of first index to be contoured
(inclusive).
C Array of contour levels (in the same units as the
data in array A); dimension at least NC.
NC number of contour levels (less than or equal to
dimension of C). The absolute value of this
argument is used (for compatibility with PGCONT,
where the sign of NC is significant).
TR 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.
BLANK Elements of array A that are exactly equal to
this value are ignored (blanked).
TLEN Length of ticks in world coordinates. If TLEN is
positive, the direction of the ticks is toward
a maximum. If it is a negative number, it points
to a minimum.
TSIZE Separation of ticks in grids.
Description: Draw a contour map of an array. This routine is the same as
PGCONS, except that array elements that have the "magic value"
defined by argument BLANK are ignored, making gaps in the
contour map. The routine may be useful for data measured on
most but not all of the points of a grid. It also plots
ticks normal to contour. The ticks have length TLEN and are
plotted at i mod TSTEP.
Updates: Nov 14, 1994: VOG Document created.