xref: /libCEED/tests/t312-basis.c (revision a8de75f0ba69dfecd93c7d0093c041c0285ffd21)
1*a8de75f0Sjeremylt /// @file
2*a8de75f0Sjeremylt /// Test integration with a 2D Simplex non-tensor H1 basis
3*a8de75f0Sjeremylt /// \test Test integration with a 2D Simplex non-tensor H1 basis
4*a8de75f0Sjeremylt #include <ceed.h>
5*a8de75f0Sjeremylt #include <math.h>
6*a8de75f0Sjeremylt #include "t310-basis.h"
7*a8de75f0Sjeremylt 
8*a8de75f0Sjeremylt double feval(double x1, double x2) {
9*a8de75f0Sjeremylt   return x1*x1 + x2*x2 + x1*x2 + 1;
10*a8de75f0Sjeremylt }
11*a8de75f0Sjeremylt 
12*a8de75f0Sjeremylt int main(int argc, char **argv) {
13*a8de75f0Sjeremylt   Ceed ceed;
14*a8de75f0Sjeremylt   const CeedInt P = 6, Q = 4, dim = 2;
15*a8de75f0Sjeremylt   CeedBasis b;
16*a8de75f0Sjeremylt   CeedScalar qref[dim*Q], qweight[Q];
17*a8de75f0Sjeremylt   CeedScalar interp[P*Q], grad[dim*P*Q], weights[Q];
18*a8de75f0Sjeremylt   CeedScalar xr[] = {0., 0.5, 1., 0., 0.5, 0., 0., 0., 0., 0.5, 0.5, 1.};
19*a8de75f0Sjeremylt   CeedScalar in[P], out[Q], sum;
20*a8de75f0Sjeremylt 
21*a8de75f0Sjeremylt   buildmats(qref, qweight, interp, grad);
22*a8de75f0Sjeremylt 
23*a8de75f0Sjeremylt   CeedInit(argv[1], &ceed);
24*a8de75f0Sjeremylt   CeedBasisCreateH1(ceed, CEED_TRIANGLE, 1, P, Q, interp, grad, qref, qweight,
25*a8de75f0Sjeremylt                     &b);
26*a8de75f0Sjeremylt 
27*a8de75f0Sjeremylt   // Interpolate function to quadrature points
28*a8de75f0Sjeremylt   for (int i=0; i<P; i++)
29*a8de75f0Sjeremylt     in[i] = feval(xr[0*P+i], xr[1*P+i]);
30*a8de75f0Sjeremylt   CeedBasisApply(b, 1, CEED_NOTRANSPOSE, CEED_EVAL_INTERP, in, out);
31*a8de75f0Sjeremylt   CeedBasisApply(b, 1, CEED_NOTRANSPOSE, CEED_EVAL_WEIGHT, NULL, weights);
32*a8de75f0Sjeremylt 
33*a8de75f0Sjeremylt   // Check values at quadrature points
34*a8de75f0Sjeremylt   sum = 0;
35*a8de75f0Sjeremylt   for (int i=0; i<Q; i++)
36*a8de75f0Sjeremylt     sum += out[i]*weights[i];
37*a8de75f0Sjeremylt   if (fabs(sum - 17./24.) > 1e-10)
38*a8de75f0Sjeremylt     printf("%f != %f\n", sum, 17./24.);
39*a8de75f0Sjeremylt 
40*a8de75f0Sjeremylt   CeedBasisDestroy(&b);
41*a8de75f0Sjeremylt   CeedDestroy(&ceed);
42*a8de75f0Sjeremylt   return 0;
43*a8de75f0Sjeremylt }
44