Contents of the GRID.DOC file
LAPLACE solves Laplace's equation in two dimensions using a square
grid and writes a file of calculated potentials at grid points.
GRID reads this file and generates a display file for the grid
itself. GRAPH (in PC-BLUE volume 230) can be used display this
grid, superimposed on the original boundaries and/or the contours
calculated by CONTOUR. Seeing the grid makes it easier to judge
whether it is fine enough for realistic results.
A>laplace plates -m 3
A>grid plates.pot >plates.g
A>graph plates plates.g -m 1 1 3 -e
LAPLACE reads the boundary conditions in "plates" and writes its
output to "plates.pot". GRID's output is written to "plates.g".
GRAPH displays both "plates" and "plates.g". The arguments of the
-m switch tell GRAPH to display the two curves in "plates" in line
style 1 (white solid line of width 1) and the single curve in
"plates.g" in line style 3 (white dotted line of width 1). The -e
switch forces GRAPH to make the x and y scales equal to avoid
To add potential contour lines to the display, add these commands:
A>graph plates plates.g plates.cnt -m 1 1 60 10 -e
CONTOUR writes its output to "plates.cnt". The arguments of the -m
switch tell GRAPH to display the grid in color 6 (gray on an EGA)
and contours in color 1 (yellow on an EGA).
James R. Van Zandt , 27 Spencer Dr., Nashua NH 03062,
603-888-2272. Resale forbidden, distribution encouraged, comments