Changes between Version 5 and Version 6 of adherelinux/mex

Timestamp:

Jul 17, 2010, 9:17:32 PM (14 years ago)

Author:

adherelinux

Comment:

--

adherelinux/mex

@@ -4 +4 @@
 
 進入mexfunction我們就可以寫C、Fortran程式了。然而若可以寫C程式，這樣的話我們也可以利用GPU來做運算。[[br]]
-以下舉例一個範例。利用Matlab輸入兩個方陣，作相加。
+
 mexFunction的框架如下:
 void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
@@ -19 +19 @@
 prhs(Type = const array of pointers to mxArrays): all of the pointers to the mxArrays of input data for instance (呼叫函式時，等號右邊之變數本體[[br]]
 
+以下舉例一個範例。利用Matlab輸入兩個向量作相加。
+
+程式碼如下:檔名為add.c
+
+#include "mex.h"
+void mexFunction(int nlhs, mxArray *plhs[],int nrhs, const mxArray *prhs[])
+{
+  int i, j, mA, nA, mB, nB, nMatSize;
+  double *A, *B, *C;
+  /*input_check */
+  if (nrhs != 2)
+    mexErrMsgTxt("The input must 2");
+  if (nlhs != 1)
+    mexErrMsgTxt("The input must 1");
+  mA = mxGetM(prhs[0]);
+  nA = mxGetN(prhs[0]);
+  mB = mxGetM(prhs[1]);
+  nB = mxGetN(prhs[1]);
+
+  printf("mA= %d\n",mA);
+  if (mA != mB ||nA != nB)
+    mexErrMsgTxt("The size must identical") ;
+
+  /*output to buffer*/
+  plhs[0]=mxCreateDoubleMatrix(mA,nA,mxREAL);
+  /*get value*/
+  A = mxGetPr(prhs[0]);
+  B = mxGetPr(prhs[1]);
+  C = mxGetPr(plhs[0]);
+  /*sum*/
+  nMatSize = mA * nA;
+  for (i=0; i<nMatSize; i++)
+    {
+      C[i] = A[i] + B[i];
+    }
+  /*result*/
+  mexPrintf("ending");
+}
+
+how to compile and run
+>mex add.c
+>a = [1 2 3 4];
+>b = [1 2 3 4];
+>c = add(a,d)
+mA=1
+ending
+c =
+2 4 6 8 
+
+