basis - pull BasisIsCollocated helper to interface level

Author: jeremylt

backends/ref/ceed-ref-basis.c

@@ -286,17 +286,7 @@ int CeedBasisCreateTensorH1_Ref(CeedInt dim, CeedInt P_1d, CeedInt Q_1d, const C
 
   CeedCallBackend(CeedCalloc(1, &impl));
   // Check for collocated interp
-  if (Q_1d == P_1d) {
-    bool has_collocated = true;
-
-    for (CeedInt i = 0; i < P_1d; i++) {
-      has_collocated = has_collocated && (fabs(interp_1d[i + P_1d * i] - 1.0) < 1e-14);
-      for (CeedInt j = 0; j < P_1d; j++) {
-        if (j != i) has_collocated = has_collocated && (fabs(interp_1d[j + P_1d * i]) < 1e-14);
-      }
-    }
-    impl->has_collo_interp = has_collocated;
-  }
+  CeedCallBackend(CeedBasisIsCollocated(basis, &impl->has_collo_interp));
   // Calculate collocated grad
   if (Q_1d >= P_1d && !impl->has_collo_interp) {
     CeedCallBackend(CeedMalloc(Q_1d * Q_1d, &impl->collo_grad_1d));

include/ceed/backend.h

@@ -331,6 +331,7 @@ CEED_EXTERN const char *const CeedFESpaces[];
 CEED_EXTERN int CeedBasisGetCollocatedGrad(CeedBasis basis, CeedScalar *colo_grad_1d);
 CEED_EXTERN int CeedBasisGetChebyshevInterp1D(CeedBasis basis, CeedScalar *chebyshev_interp_1d);
 CEED_EXTERN int CeedBasisIsTensor(CeedBasis basis, bool *is_tensor);
+CEED_EXTERN int CeedBasisIsCollocated(CeedBasis basis, bool *is_collocated);
 CEED_EXTERN int CeedBasisGetData(CeedBasis basis, void *data);
 CEED_EXTERN int CeedBasisSetData(CeedBasis basis, void *data);
 CEED_EXTERN int CeedBasisReference(CeedBasis basis);

interface/ceed-basis.c

@@ -780,6 +780,32 @@ int CeedBasisIsTensor(CeedBasis basis, bool *is_tensor) {
   return CEED_ERROR_SUCCESS;
 }
 
+/**
+  @brief Determine if given `CeedBasis` has nodes collocated with quadrature points
+
+  @param[in]  basis     `CeedBasis`
+  @param[out] is_tensor Variable to store collocated status
+
+  @return An error code: 0 - success, otherwise - failure
+
+  @ref Backend
+**/
+int CeedBasisIsCollocated(CeedBasis basis, bool *is_collocated) {
+  if (basis->is_tensor_basis && (basis->Q_1d == basis->P_1d)) {
+    *is_collocated = true;
+
+    for (CeedInt i = 0; i < basis->P_1d; i++) {
+      *is_collocated = *is_collocated && (fabs(basis->interp_1d[i + basis->P_1d * i] - 1.0) < 10 * CEED_EPSILON);
+      for (CeedInt j = 0; j < basis->Q_1d; j++) {
+        if (j != i) *is_collocated = *is_collocated && (fabs(basis->interp_1d[j + basis->P_1d * i]) < 10 * CEED_EPSILON);
+      }
+    }
+  } else {
+    *is_collocated = false;
+  }
+  return CEED_ERROR_SUCCESS;
+}
+
 /**
   @brief Get backend data of a `CeedBasis`