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我正在嘗試使用culaSgels函數來解析Ax = B。cula使用culaSgels - 錯誤的參數?
我修改了cula包的systemSolve示例。
void culaFloatExample()
{
int N=2;
int NRHS = 2;
int i,j;
double cula_time,start_time,end_time;
culaStatus status;
culaFloat* A = NULL;
culaFloat* B = NULL;
culaFloat* X = NULL;
culaFloat one = 1.0f;
culaFloat thresh = 1e-6f;
culaFloat diff;
printf("Allocating Matrices\n");
A = (culaFloat*)malloc(N*N*sizeof(culaFloat));
B = (culaFloat*)malloc(N*N*sizeof(culaFloat));
X = (culaFloat*)malloc(N*N*sizeof(culaFloat));
if(!A || !B)
exit(EXIT_FAILURE);
printf("Initializing CULA\n");
status = culaInitialize();
checkStatus(status);
// Set A
A[0]=1;
A[1]=2;
A[2]=3;
A[3]=4;
// Set B
B[0]=5;
B[1]=6;
B[2]=2;
B[3]=3;
printf("Calling culaSgels\n");
// Run CULA's version
start_time = getHighResolutionTime();
status = culaSgels('N',N,N, NRHS, A, N, A, N);
end_time = getHighResolutionTime();
cula_time = end_time - start_time;
checkStatus(status);
printf("Verifying Result\n");
for(i = 0; i < N; ++i){
for (j=0;j<N;j++)
{
diff = X[i+j*N] - B[i+j*N];
if(diff < 0.0f)
diff = -diff;
if(diff > thresh)
printf("\nResult check failed: X[%d]=%f B[%d]=%f\n", i, X[i+j*N],i, B[i+j*N]);
printf("\nResults:X= %f \t B= %f:\n",X[i+j*N],B[i+j*N]);
}
}
printRuntime(cula_time);
printf("Shutting down CULA\n\n");
culaShutdown();
free(A);
free(B);
}
我使用culaSgels('N',N,N, NRHS, A, N, A, N);
解決系統但:
1)結果表明我,X = 0,但B的每一個元素是正確的。 此外,它顯示我的
結果檢查失敗消息
2)研究的參考手冊,上面說的最後一個參數之前的一個參數(AI有),應該是矩陣B存儲columnwised,但如果我使用「B」而不是「A」作爲參數,那麼我沒有得到正確的B矩陣。
你爲什麼不把B傳給SGELS電話?這*可能*如何工作? – talonmies
@talonmies:好的,謝謝!我錯過了理解。 – George