OpenCV学习——矩阵的单点读取与存储

/*
* =====================================================================================
*
* Filename: array1.c
*
* Description: To show how to set and get a Array
*
* Version: 1.0
* Created: 01/08/2009 09:17:17 PM
* Revision: none
* Compiler: gcc
*
* Author: Futuredaemon (BUPT), [e-mail]
* Company: BUPT_UNITED
*
* =====================================================================================
*/

#pragma comment( lib, "cxcore.lib" )
#include "cv.h"
#include <stdio.h>
int main()
{
CvMat* mat = cvCreateMat(3,3,CV_32FC1);
cvZero(mat);//将矩阵置0
//为矩阵元素赋值
CV_MAT_ELEM( *mat, float, 0, 0 ) = 1.f;
CV_MAT_ELEM( *mat, float, 0, 1 ) = 2.f;
CV_MAT_ELEM( *mat, float, 0, 2 ) = 3.f;
CV_MAT_ELEM( *mat, float, 1, 0 ) = 4.f;
CV_MAT_ELEM( *mat, float, 1, 1 ) = 5.f;
CV_MAT_ELEM( *mat, float, 1, 2 ) = 6.f;
CV_MAT_ELEM( *mat, float, 2, 0 ) = 7.f;
CV_MAT_ELEM( *mat, float, 2, 1 ) = 8.f;
CV_MAT_ELEM( *mat, float, 2, 2 ) = 9.f;
//获得矩阵元素(0,2)的值
float *p = (float*)cvPtr2D(mat, 0, 2);
printf("%f\n",*p);
return 0;
}