1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
| /* interpolation */
#include "utils.h"
scalar v[];
int main (int argc, char ** argv)
{
size (1.[0]);
origin (-0.5, -0.5);
for (int n = 8; n <= 64; n *= 2) {
init_grid (n);
refine (level == log2(n) && sq(x) + sq(y) > sq(0.49));
refine (level <= log2(n) + 1 && sq(x) + sq(y) > sq(0.55));
foreach()
v[] = cos(2.*pi*x)*cos(2.*pi*y);
// FILE * fp = fopen("error","w");
double emax = 0.;
int ni = 4*n + 7;
double Delta = 1./ni;
for (int i = 0; i < ni; i++) {
double x = X0 + Delta*i;
for (int j = 0; j < ni; j++) {
double y = Y0 + Delta*j;
double e = fabs (cos(2.*pi*x)*cos(2.*pi*y) - interpolate (v, x, y));
// fprintf (fp, "%g %g %g\n", x, y, e);
if (e > emax) emax = e;
}
// fprintf (fp, "\n");
}
// fclose (fp);
fprintf (stderr, "%d %g\n", n*4, emax);
if (n == 16)
output_cells (stdout);
}
}
|
