Best method to save and load data in a file for opencv 3.1 version

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Have you checked this? https://docs.opencv.org/3.0-beta/doc/...

link in master is better https://docs.opencv.org/master/dd/d74... or in 3.1 https://docs.opencv.org/3.1.0/dd/d74/...

I have checked this link. But it make confuse me. Can you tell me that how can i save data to .xml file from "vector<mat> preprocessedFaces" variable and how can load data from file to this variable.

I have tried for .txt file.But did not used filestorage class.

If you can provide steps,it will great for me.

I have used these Miki's line of codes. But it gives error when try to read data from the file.

 //variable
  vector<Mat> preprocessedFaces;

  //write data in a file, its working fine
  for( int face_index = 0; face_index < preprocessedFaces.size(); face_index++ ) 
  {
    matwrite("train_data.txt",preprocessedFaces[face_index]);
  }

  //got error when tried to read data...here i got 10,because written data for 10 times 
  for(int index=0; index<10; index++)
  {
    preprocessedFaces[index] = matread("train_data.txt");   
  }

@kishan patel if you've got problem wuth miki code's you should ask to miki.

About xml it's in tutorial :

    fs << "R" << R;                                      // cv::Mat
    fs << "T" << T;

Okay LBerger. But i could not contact with him. If you got any correction from above lines of codes.Let me inform.

you cannot save a vector<mat> in one file using matwrite. To read it is preprocessedFaces.push_back(matread("train_data.txt")); you will get 10 images preprocessedFaces but always same image

Okay. So how can i save that type of data and load it after to that type of data-variable.