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Public Domain Aeronautical Software (PDAS)  

Viewer is a program to draw three-dimensional surfaces of the form z = f(x,y). The function f and the boundary values for x and y are the inputs. The surface thus defined may be drawn after arbitrary rotations.

The method used is division into a uniform rectangular grid of the given x and y ranges. The values of the supplied function at the grid points (x, y) are calculated and stored; this defines the surface. The surface is portrayed by connecting successive (y,z) points with straight-line segments for each x value on the grid and, in turn, connecting successive (x,z) points for each fixed y value on the grid. These lines are then projected by parallel projection onto the fixed yz-plane for plotting.

The program produces a file called viewer.gnu that may be used with gnuplot. For example

gnuplot>plot 'viewer.gnu' with lines

Reference: Cantright, R.Bruce, Jr.; and Swigert, Paul: Plot3D - A Package of Fortran Subprograms to Draw Three-Dimensional Surfaces. NASA Technical Memorandum X-1598, June 1968.

PDAS home > Contents > Function Viewer
Public Domain Aeronautical Software (PDAS)