xref: /libCEED/tests/t312-basis.c (revision ba4bcd917872bbba2ca5b7fccd7fd5f16d3aa2e4)
1 /// @file
2 /// Test integration with a 2D Simplex non-tensor H1 basis
3 /// \test Test integration with a 2D Simplex non-tensor H1 basis
4 #include <ceed.h>
5 #include <math.h>
6 #include "t310-basis.h"
7 
8 double feval(double x1, double x2) {
9   return x1*x1 + x2*x2 + x1*x2 + 1;
10 }
11 
12 int main(int argc, char **argv) {
13   Ceed ceed;
14   const CeedInt P = 6, Q = 4, dim = 2;
15   CeedBasis b;
16   CeedScalar qref[dim*Q], qweight[Q];
17   CeedScalar interp[P*Q], grad[dim*P*Q], weights[Q];
18   CeedScalar xr[] = {0., 0.5, 1., 0., 0.5, 0., 0., 0., 0., 0.5, 0.5, 1.};
19   CeedScalar in[P], out[Q], sum;
20 
21   buildmats(qref, qweight, interp, grad);
22 
23   CeedInit(argv[1], &ceed);
24   CeedBasisCreateH1(ceed, CEED_TRIANGLE, 1, P, Q, interp, grad, qref, qweight,
25                     &b);
26 
27   // Interpolate function to quadrature points
28   for (int i=0; i<P; i++)
29     in[i] = feval(xr[0*P+i], xr[1*P+i]);
30   CeedBasisApply(b, 1, CEED_NOTRANSPOSE, CEED_EVAL_INTERP, in, out);
31   CeedBasisApply(b, 1, CEED_NOTRANSPOSE, CEED_EVAL_WEIGHT, NULL, weights);
32 
33   // Check values at quadrature points
34   sum = 0;
35   for (int i=0; i<Q; i++)
36     sum += out[i]*weights[i];
37   if (fabs(sum - 17./24.) > 1e-10)
38     printf("%f != %f\n", sum, 17./24.);
39 
40   CeedBasisDestroy(&b);
41   CeedDestroy(&ceed);
42   return 0;
43 }
44