从MATLAB访问在MEX中创建的稀疏矩阵
|
我按照此处显示的示例在MEX文件中创建了一个稀疏矩阵。现在，我如何从MATLAB整体访问此矩阵。
#define NZMAX 4
#define ROWS 4
#define COLS 2
int rows=ROWS, cols=COLS;
mxArray *ptr_array; /* Pointer to created sparse array. */
static double static_pr_data[NZMAX] = {5.8, 6.2, 5.9, 6.1};
static int static_ir_data[NZMAX] = {0, 2, 1, 3};
static int static_jc_data[COLS+1] = {0, 2, 4};
double *start_of_pr;
int *start_of_ir, *start_of_jc;
mxArray *array_ptr;
/* Create a sparse array. */
array_ptr = mxCreateSparse(rows, cols, NZMAX, mxREAL);
/* Place pr data into the newly created sparse array. */
start_of_pr = (double *)mxGetPr(array_ptr);
memcpy(start_of_pr, static_pr_data, NZMAX*sizeof(double));
/* Place ir data into the newly created sparse array. */
start_of_ir = (int *)mxGetIr(array_ptr);
memcpy(start_of_ir, static_ir_data, NZMAX*sizeof(int));
/* Place jc data into the newly created sparse array. */
start_of_jc = (int *)mxGetJc(array_ptr);
memcpy(start_of_jc, static_jc_data, NZMAX*sizeof(int));
/* ... Use the sparse array in some fashion. */
/* When finished with the mxArray, deallocate it. */
mxDestroyArray(array_ptr);
static_pr_data
ic_data
jc_data
没有找到相关结果
已邀请:
2 个回复
抵浮细
而不是破坏数组，您需要将其作为MEX函数的输出返回。您的MEX函数C / C ++源代码应具有一个名为（MEX函数的入口）的函数，如下所示：要从MEX函数返回输出，请将其分配到数组中，如下所示：将代码编译成MEX函数（我们称之为）。像这样从MATLAB调用它：现在，ѭ11是一个MATLAB变量，其中包含您在MEX函数中创建的稀疏矩阵。 至于以行为主的格式存储数据，这是不可能的。 MATLAB仅处理列为主的稀疏矩阵。娠频摩
// Fetch struct field using a temp variable std::string tempName = std::string(field_name) + \"_temp\"; std::string fetchField = tempName + \" = \" + std::string(struct_name) + \".\" + std::string(field_name) + \"; \"; matlabExecute(ep, fetchField); mxArray *matlabArray = engGetVariable(ep, tempName.c_str()); // Get variable elements const int count = mxGetNumberOfElements(matlabArray); T *data = (T*) mxGetData(matlabArray); for (int i = 0; i < count; i++) vector[i] = _isnan(data[i]) ? (T) (int) -9999 : (T) data[i]; // Clear temp variable std::string clearTempVar = \"clear \" + tempName + \"; \"; matlabExecute(ep, clearTempVar); // Destroy mx object mxDestroyArray(matlabArray);