我不明白计算线性方程组时的错误是什么。我需要使用 C 中的 Scilab API 来求解线性方程组，但我得到的值太小了。
我不明白计算线性方程组时的错误是什么。我需要使用 C ，但我得到的值太小了。检查了解决方案，答案应该是： [0;1] .Free 被特别注释，因为程序会立即崩溃。
我以为错误出在 dgesv_ ，但这很奇怪，因为它是一个 Scilab 函数，为什么它解析不正确。也许输出有问题？
代码：
#include "api_scilab.h"
#include "Scierror.h"
#include "BOOL.h"
#include "localization.h"
extern void dgesv_(int* n, int* nrhs, double* A, int* lda, int* ipiv, double* b, int* ldb, int* info);
static const char fname[] = "foo6";
int sci_foo6(scilabEnv env, int nin, scilabVar* in, int nopt, scilabOpt* opt, int nout, scilabVar* out)
{
int i = 0;
int n = 0; // System dimension
double* A = NULL; // Coefficient matrix
double* b = NULL; // Right-hand side vector
double* x = NULL; // Solution
int info = 0;
/* Check the number of input and output arguments */
if (nin != 2 || nout != 1) {
Scierror(77, _("%s: Wrong number of input or output arguments: 2 inputs and 1 output expected.\n"), fname);
return 1;
}
/* Check the types of input arguments */
if (scilab_isDouble(env, in[0]) == 0 || scilab_isMatrix2d(env, in[0]) == 0 ||
scilab_isComplex(env, in[0]) == 1 || scilab_isDouble(env, in[1]) == 0 ||
scilab_isMatrix2d(env, in[1]) == 0 || scilab_isComplex(env, in[1]) == 1) {
Scierror(999, _("%s: Wrong type for input arguments. Double matrices expected.\n"), fname);
return 1;
}
/* Get the dimension of the coefficient matrix */
int rowA = 0, colA = 0, rowB = 0, colB = 0;
scilab_getDim2d(env, in[0], &rowA, &colA);
scilab_getDim2d(env, in[1], &rowB, &colB);
if (rowA != colA || rowB != rowA || colB != 1) {
Scierror(999, _("%s: Incorrect dimensions. Coefficient matrix should be square and vector should be a column vector of the same size.\n"), fname);
return 1;
}
n = rowA;
/* Get data from input arguments */
scilab_getDoubleArray(env, in[0], &A);
scilab_getDoubleArray(env, in[1], &b);
/* Solve the system of linear equations */
x = (double*)malloc(n * sizeof(double));
dgesv_(&n, &n, A, &n, b, x, &n, &info);
if (info != 0) {
Scierror(999, _("%s: LAPACK dgesv function failed with error code %d.\n"), fname, info);
free(x);
return 1;
}
/* Create the output argument and copy the result */
out[0] = scilab_createDoubleMatrix2d(env, 1, n, 0);
double* xPtr = NULL;
scilab_getDoubleArray(env, out[0], &xPtr);
for (i = 0; i < n; i++) {
xPtr[i] = x[i];
}
//free(x);
return 0;
}
结论：
--> A = [2, 1; -1, 2];
--> b = [1; 2];
--> x = foo6(A, b);
--> disp(x);
5.27D-314 2.64D-314
尝试通过 Scilab API 解决 SLAU，但收效甚微。我不确定我做得对不对。
