Name: PGCONF Purpose: fill between two contours Category: GRAPHICS File: pgplot.src Author: T.J. Pearson Use: see description below. Description: SUBROUTINE PGCONF (A, IDIM, JDIM, I1, I2, J1, J2, C1, C2, TR) INTEGER IDIM, JDIM, I1, I2, J1, J2 REAL A(IDIM,JDIM), C1, C2, TR(6) Shade the region between two contour levels of a function defined on the nodes of a rectangular grid. The routine uses the current fill attributes, hatching style (if appropriate), and color index. If you want to both shade between contours and draw the contour lines, call this routine first (once for each pair of levels) and then CALL PGCONT (or PGCONS) to draw the contour lines on top of the shading. Note 1: This routine is not very efficient: it generates a polygon fill command for each cell of the mesh that intersects the desired area, rather than consolidating adjacent cells into a single polygon. Note 2: If both contours intersect all four edges of a particular mesh cell, the program behaves badly and may consider some parts of the cell to lie in more than one contour range. Note 3: If a contour crosses all four edges of a cell, this routine may not generate the same contours as PGCONT or PGCONS (these two routines may not agree either). Such cases are always ambiguous and the routines use different approaches to resolving the ambiguity. 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). C1, C2 (input) : contour levels; note that C1 must be less than C2. 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.