Function:s2funxy

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s2funxy

Draw the surface described by the provided function fxy.

Prototype

void s2funxy(float(*fxy)(float*,float*), int nx, int ny, float xmin, float xmax, float ymin, float ymax, int ctl);

Description

Draw the surface described by the function fxy. The function is evaluated on a nx * ny grid whose world coordinates extend from (xmin,ymin) to (xmax,ymax). The ctl argument has the following effect:

  • ctl = 0: curve plotted in current window and viewport. Caller is responsible for setting the viewport and world coordinate system suitably.
  • ctl = 1: s2env is called automatically to fit the plot in the current viewport.

Beware that these functions consume memory to store all the function evaluations prior to triangulating the surface.

See Also

s2funxz Draw the surface described by the provided function fxz.
s2funyz Draw the surface described by the provided function fyz.
s2funxyr Draw surface as per s2funxy, but with explicit settings for the colour range mapping.
s2env Convenience function which sets the plotting environment.

PGPLOT Equivalent

PGFUNX

Code Example

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "s2plot.h"

#define XLIMIT 1.0
#define YLIMIT 1.0
#define ZLIMIT 1.0

float fxy(float *x, float *y)
{
   return ((*x)*(*x) + 0.25*(*y)*(*y));         /* Function to evaluate */
}

float fxz(float *x, float *z)
{
   return (0.1*(*x)*(*x) + 0.1*(*z)*(*z));      /* Function to evaluate */
}

float fyz(float *y, float *z)
{
   return (-0.3*(*y)*(*y) - 0.3*(*z)*(*z));     /* Function to evaluate */
}

int main(int argc, char *argv[])
{
   int nx = 64, ny = 64, nz = 64;
                                /* Resolution of grids to plot function on */
   int ctl = 0;                 /* User responsible for setting environ */

   float x1 = -XLIMIT*1.5, x2 = +XLIMIT*1.5;    /* World coordinates */
   float y1 = -YLIMIT*1.5, y2 = +YLIMIT*1.5;
   float z1 = -ZLIMIT*1.5, z2 = +ZLIMIT*1.5;

   s2opend("/?",argc,argv);                     /* Open the display */
   s2swin(x1,x2,y1,y2,z1,z2);                   /* Set the window coordinates */
   s2box("BCDET",0,0,"BCDET",0,0,"BCDET",0,0);  /* Draw coordinate box */

   s2icm("rainbow",1000,2000);
   s2scir(1000,2000);
   s2funxy(fxy, nx, ny, -XLIMIT,XLIMIT, -YLIMIT,YLIMIT, ctl);
                                /* Functional surface in X-Y plane */

   s2icm("astro",2000,3000);
   s2scir(2000,3000);
   s2funxz(fxz, nx, nz, -XLIMIT,XLIMIT, -ZLIMIT,ZLIMIT, ctl);
                                /* Functional surface in X-Z plane */

   s2icm("mgreen",3000,4000);
   s2scir(3000,4000);
   s2funyz(fyz, ny, nz, -YLIMIT,YLIMIT, -ZLIMIT,ZLIMIT, ctl);
                                /* Functional surface in Y-Y plane */

   s2show(1);                   /* Open the s2plot window */

   return 1;
}

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Retrieved from "https://astronomy.swin.edu.au/s2plot/index.php?title=Function:s2funxy"
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