Merge pull request #530 from Cytnx-dev/return-zero-det

Det() returns zero for the sigular matrix
Cytnx-dev · Dec 5, 2024 · 32f2ef7 · 32f2ef7
2 parents dd72877 + eb67ff2
commit 32f2ef7
Showing 1 changed file with 12 additions and 4 deletions.
diff --git a/src/backend/linalg_internal_gpu/cuDet_internal.cu b/src/backend/linalg_internal_gpu/cuDet_internal.cu
@@ -34,7 +34,9 @@ namespace cytnx {
 
       int info;
       checkCudaErrors(cudaMemcpy(&info, devInfo, sizeof(int), cudaMemcpyDeviceToHost));
-      cytnx_error_msg(info != 0, "[ERROR] cusolverDnZgetrf fail with info= %d\n", info);
+      cytnx_error_msg(info < 0, "[ERROR] cusolverDnZgetrf fail with info= %d\n", info);
+      // TODO: info > 0 means U[info - 1, info - 1] is zero, which implies the determinant is
+      // zero. The steps below can be skipped.
 
       // since we do unify mem, direct access element is possible:
       od[0] = 1;
@@ -79,7 +81,9 @@ namespace cytnx {
 
       int info;
       checkCudaErrors(cudaMemcpy(&info, devInfo, sizeof(int), cudaMemcpyDeviceToHost));
-      cytnx_error_msg(info != 0, "[ERROR] cusolverDnCgetrf fail with info= %d\n", info);
+      cytnx_error_msg(info < 0, "[ERROR] cusolverDnCgetrf fail with info= %d\n", info);
+      // TODO: info > 0 means U[info - 1, info - 1] is zero, which implies the determinant is
+      // zero. The steps below can be skipped.
 
       // since we do unify mem, direct access element is possible:
       od[0] = 1;
@@ -124,7 +128,9 @@ namespace cytnx {
 
       int info;
       checkCudaErrors(cudaMemcpy(&info, devInfo, sizeof(int), cudaMemcpyDeviceToHost));
-      cytnx_error_msg(info != 0, "[ERROR] cusolverDnDgetrf fail with info= %d\n", info);
+      cytnx_error_msg(info < 0, "[ERROR] cusolverDnDgetrf fail with info= %d\n", info);
+      // TODO: info > 0 means U[info - 1, info - 1] is zero, which implies the determinant is
+      // zero. The steps below can be skipped.
 
       // since we do unify mem, direct access element is possible:
       od[0] = 1;
@@ -169,7 +175,9 @@ namespace cytnx {
 
       int info;
       checkCudaErrors(cudaMemcpy(&info, devInfo, sizeof(int), cudaMemcpyDeviceToHost));
-      cytnx_error_msg(info != 0, "[ERROR] cusolverDnSgetrf fail with info= %d\n", info);
+      cytnx_error_msg(info < 0, "[ERROR] cusolverDnSgetrf fail with info= %d\n", info);
+      // TODO: info > 0 means U[info - 1, info - 1] is zero, which implies the determinant is
+      // zero. The steps below can be skipped.
 
       // since we do unify mem, direct access element is possible:
       od[0] = 1;