由于sort函数和sortId函数是对一行或一列进行排序的，所以对整个需要reshape一下，还要指定是行还是列。
 
	Mat c1 = (Mat_<uchar>(3, 3) << 1, 5, 6, 2, 4, 3, 8, 9, 7);
	Mat c3 = c1.reshape(1, 9);
	cv::sort(c3, c3, SORT_EVERY_COLUMN + CV_SORT_ASCENDING);
 
sortid返回是大小的索引
 
	Mat c1 = (Mat_<uchar>(3, 3) << 1, 5, 6, 2, 4, 3, 8, 9, 7);
	Mat c2(c1);
	//sort(c2, c2, CV_SORT_EVERY_ROW + CV_SORT_ASCENDING);
	sortIdx(c1, c2, SORT_EVERY_COLUMN + SORT_ASCENDING);
 
 
 
 
 
 
 
 

代码：
 
Mat mat_dst; //mat_src：需要排序的Mat类型的矩阵变量
mat_src.reshape(1,1).copyTo(mat_dst);
cv::sort(mat_dst, mat_dst, CV_SORT_EVERY_ROW + CV_SORT_ASCENDING);
cout << mat_dst << endl; 
 
分析：
 
reshape()函数 
 a. Mat cv::Mat::reshape( int cn, int rows = 0 ) 
 OpenCV官方讲解得非常清楚：
 
 
b. Mat cv::Mat::reshape( int cn, int newndims, const int * newsz ) 
  
 c. Examples 
 可参考：http://docs.opencv.org/3.2.0/d2/dc0/pca_8cpp-example.html#a17
sort()函数 
 OpenCV官方介绍：
 
 
相关函数： 
 void cv::sortIdx( InputArray src, OutputArray dst, int flags )； 

void sortMat(Mat &stats, int colId){
    //根据指定列以行为单位排序
    
    Mat sorted_index;
    cv::sortIdx(stats, sorted_index, cv::SORT_EVERY_COLUMN + cv::SORT_DESCENDING);
    // 注意此处是DESCENDING 如果要升序需要改成ASCENDING
    
    sorted_index = sorted_index.col(colId);
    Mat sorted_stats = stats.clone();
    int row_num = sorted_index.rows;
    for(int i = 0; i < row_num; i++){
        int _idx = sorted_index.at<int>(i, 0);
        sorted_stats.row(i) = stats.row(_idx) + 0;//必须加0否则会出很难debug的错误
    }
    stats = sorted_stats;
    return;
}

 
原文：http://blog.csdn.net/qing101hua/article/details/52817373
 

 
 
sortIdx 函数 对元素进行排序， 返回对应的排序索引
 
 
 
 
 
  

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Mat c1 = (Mat_<double>(3,3) << 1, 5 , 6 , 2 , 4, 2, 5, 9, 4);  
Mat c2(c1);  
sortIdx(c1, c2, SORT_EVERY_COLUMN + SORT_ASCENDING);  
cout << "c1: \n" << c1 << endl;  
cout << "c2: \n" << c2 << endl;  
 
 
  Mat c1 = (Mat_<double>(3,3) << 1, 5 , 6 , 2 , 4, 2, 5, 9, 4);
  Mat c2(c1);
  sortIdx(c1, c2, SORT_EVERY_COLUMN + SORT_ASCENDING);
  cout << "c1: \n" << c1 << endl;
  cout << "c2: \n" << c2 << endl;

 


 
 

 
 
sort 排序函数， C++中sort函数 详细介绍参见 ：  http://blog.csdn.net/qing101hua/article/details/52822060
 

 
 
 
 
 
 
  

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// sort  Mat(3,3)  
int* c1begin = c1.ptr<int>(0);  
int* c1end = c1.ptr<int>(2);  
sort(c1begin[0], c1end[2]); // 该行代码 编译报错  
cout << "c1: \n " << c1 << endl;  
 
 
  // sort  Mat(3,3)
  int* c1begin = c1.ptr<int>(0);
  int* c1end = c1.ptr<int>(2);
  sort(c1begin[0], c1end[2]); // 该行代码 编译报错
  cout << "c1: \n " << c1 << endl;

 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(3093): error : operand of "*" must be a pointer

 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(3093): error : operand of "*" must be a pointer

 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(3093): error : no instance of function template "std::less<void>::operator()" matches the argument list

 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(2288): error : operand of "*" must be a pointer

 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(2288): error : operand of "*" must be a pointer

 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(2292): error : operand of "*" must be a pointer

 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(2292): error : operand of "*" must be a pointer

 1>  main.cu

 1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\BuildCustomizations\CUDA 7.5.targets(604,9): error MSB3721: 命令“"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v7.5\bin\nvcc.exe" -gencode=arch=compute_20,code=\"sm_20,compute_20\" --use-local-env --cl-version 2013 -ccbin "C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin\x86_amd64"  -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v7.5\include" -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v7.5\include"  -G   --keep-dir x64\Debug -maxrregcount=0  --machine 64 --compile -cudart static  -g   -DWIN32 -DWIN64 -D_DEBUG -D_CONSOLE -D_MBCS -Xcompiler "/EHsc /W3 /nologo /Od /Zi /RTC1 /MDd " -o x64\Debug\main.cu.obj "D:\work\test\wb\wb\main.cu"”已退出，返回代码为 2。

 ========== 全部重新生成:  成功 0 个，失败 1 个，跳过 0 个 ==========

 
 

 
 
 
 
 
 
  

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//sort int[9];  
int d1[] = { 2, 4, 5, 2, 1, 8, 6, 7, 9 };  
sort(d1[0], d1[7]);   // 报错 ，编译不过去  
//cout << "d1: \n" << d1 << endl;  
 
 
  //sort int[9];
  int d1[] = { 2, 4, 5, 2, 1, 8, 6, 7, 9 };
  sort(d1[0], d1[7]);   // 报错 ，编译不过去
  //cout << "d1: \n" << d1 << endl;

 报错： 
 
1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(3093): error : no instance of function template "std::less<void>::operator()" matches the argument list
 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(2288): error : operand of "*" must be a pointer
 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(2288): error : operand of "*" must be a pointer
 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(2292): error : operand of "*" must be a pointer
 1>C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\algorithm(2292): error : operand of "*" must be a pointer
 1>  main.cu
 1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\BuildCustomizations\CUDA 7.5.targets(604,9): error MSB3721: 命令“"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v7.5\bin\nvcc.exe" -gencode=arch=compute_20,code=\"sm_20,compute_20\" --use-local-env --cl-version 2013 -ccbin "C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin\x86_amd64"  -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v7.5\include" -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v7.5\include"  -G   --keep-dir x64\Debug -maxrregcount=0  --machine 64 --compile -cudart static  -g   -DWIN32 -DWIN64 -D_DEBUG -D_CONSOLE -D_MBCS -Xcompiler "/EHsc /W3 /nologo /Od /Zi /RTC1 /MDd " -o x64\Debug\main.cu.obj "D:\work\test\wb\wb\main.cu"”已退出，返回代码为 2。
 ========== 生成:  成功 0 个，失败 1 个，最新 0 个，跳过 0 个 ==========
 
 

 
 
解决：
 
将sort输入参数 改成数据索引的指针
 
1、对int[9] 进行测试， 对int[9]的前6个元素进行排序
 
 
 
 
 
  

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//sort int[9];  
int d1[9] = { 2, 4, 5, 2, 1, 8, 6, 7, 9 };  
cout << "d1[]: " << endl;  
for (int i = 0; i < 9; i++)  
 cout << d1[i] << endl;  
  
sort(d1, d1+5);   // 注意： 参数如果不是指针变量的话 会报错 ，编译不过去  
cout << "d1[]: " << endl;  
for (int i = 0; i < 6; i++)  
 cout << d1[i] << endl;  
 
 
  //sort int[9];
  int d1[9] = { 2, 4, 5, 2, 1, 8, 6, 7, 9 };
  cout << "d1[]: " << endl;
  for (int i = 0; i < 9; i++)
	  cout << d1[i] << endl;

  sort(d1, d1+5);   // 注意： 参数如果不是指针变量的话 会报错 ，编译不过去
  cout << "d1[]: " << endl;
  for (int i = 0; i < 6; i++)
	  cout << d1[i] << endl;

 


 
 
2、对Mat（3,3）的元素进行排序：
 
 
 
 
 
  

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int* c1begin = c1.ptr<int>(0);  
int* c1end = c1.ptr<int>(2);  
sort(c1begin, c1end+2);  
cout << endl<<"sort(c1begin, c1end+2)" << endl;  
cout << "c1: \n " << c1 << endl;  
  
sort(c1begin, c1end + 3);  
cout <<endl << "sort(c1begin, c1end+3)" << endl;  
cout << "c1: \n " << c1 << endl;  
 
 
  int* c1begin = c1.ptr<int>(0);
  int* c1end = c1.ptr<int>(2);
  sort(c1begin, c1end+2);
  cout << endl<<"sort(c1begin, c1end+2)" << endl;
  cout << "c1: \n " << c1 << endl;
  
  sort(c1begin, c1end + 3);
  cout <<endl << "sort(c1begin, c1end+3)" << endl;
  cout << "c1: \n " << c1 << endl;
 
 
 
 
  

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sort(c1begin, c1end);  
cout << endl << "sort(c1begin, c1end)" << endl;  
cout << "c1: \n " << c1 << endl;  
 
 
  sort(c1begin, c1end);
  cout << endl << "sort(c1begin, c1end)" << endl;
  cout << "c1: \n " << c1 << endl;