Random forest - RTrees - getSplits - type mismatch

asked 2016-03-03 12:06:31 -0500

mask2007 gravatar image

updated 2016-03-09 13:56:09 -0500

Hello,

I'm trying to access RTrees's nodes and trees. Having the following code: ``` #include <iostream>

#include <opencv2\core\core.hpp>
#include <opencv2\highgui\highgui.hpp>
#include <opencv2\ml\ml.hpp>

using namespace std;
using namespace cv;
using namespace cv::ml;

static Ptr<TrainData> prepareTrainData(Mat& pts, Mat& classes)
{
    Mat samples;
    Mat(pts).reshape(1, (int)pts.rows).convertTo(samples, CV_32F);
    Ptr<TrainData> a = TrainData::create(samples, ROW_SAMPLE, classes);
    return a;
}

int main()
{
    Mat training = (Mat_<float>(7, 2) << 1, 1, 2, 2, 3, 3, 1, 2, 3, 4, 5, 4, 3, 2);
    Mat classes = (Mat_<int>(7, 1) << 0, 0, 0, 1, 1, 2, 2);

    cout << "training data" << endl;
    cout << endl << training << " " << endl << endl;
    cout << "classes" << endl;
    cout << endl << classes << " " << endl << endl;

    Ptr<RTrees> rtrees = RTrees::create();

    rtrees->setMaxDepth(14);
    rtrees->setMinSampleCount(2);
    rtrees->setRegressionAccuracy(0.f);
    rtrees->setUseSurrogates(false);
    rtrees->setMaxCategories(3);
    rtrees->setPriors(Mat());
    rtrees->setCalculateVarImportance(false);

    rtrees->setActiveVarCount(1);
    rtrees->setTermCriteria(TermCriteria(TermCriteria::MAX_ITER, 5, 0));
    Ptr<TrainData> a = prepareTrainData(training, classes);
    rtrees->train(a);

    // my own prediction
    vector<int> roots = rtrees->getRoots();             // runtime error
    vector<DTrees::Node> nodes = rtrees->getNodes();    // runtime error
    vector<DTrees::Split> splits = rtrees->getSplits();  // runtime error

    Range range = Range(0, (int)roots.size());
    Mat sample = training.row(0);

    int nclasses = 2;
    vector<int> votes(nclasses, 0);
    Mat varIdx0 = a->getVarIdx();
    vector<int> varIdx;
    varIdx0.copyTo(varIdx);                                                        // wrong copy

    getchar();
    return 0;
}

```

I keep getting the memory access violation. Note that rt->getSplits() works by itself and I guess the problem is with the data type of splits.

Also, when I read training data information and want to copy it into a variable:

std::vector<int> catMap;
 data->getCapMap().copyTo(catMap);

it copies garbage into the carMap and I have to copy it element by element instead of using copyTo method. Do you have any idea about these two questions?

Thanks,

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Comments

which os / opencv version is it ? did you build it locally ?

(i can't reproduce any of your problems with ocv3.1 on win)

how do you setup your traindata ?

berak gravatar imageberak ( 2016-03-03 14:58:23 -0500 )edit

@berak it's Windows 10 and OpenCV 3.1. I'll put the whole code up there.

mask2007 gravatar imagemask2007 ( 2016-03-09 13:53:01 -0500 )edit