# svm predict function always return a large number

Hi all,

I trying to implement a simple sample, the purpose is tranning and detect a number. Source as following:

**Step 1: Initial data for tranning:**
I used a collect of images number for traning data,

```
Mat vectorMatToMat(vector<Mat> list) {
if (list.empty()) {
return Mat();
}
int row = list.size();
int col = list.at(0).rows * list.at(0).cols;
Mat data(row, col, CV_32FC1);
int i = 0;
for (i = 0; i < row; i++) {
Mat rowMat = list.at(i).reshape(1, 1);
rowMat.copyTo(data.row(i));
}
return data;
}
Mat vectorIntToMat(vector<int> list) {
int row = list.size();
Mat data(row, 1, CV_32SC1, &list[0]);
return data;
}
Mat dataMat = vectorMatToMat(listImageForTraining);
Mat dataLabel = vectorIntToMat(listLabel);
```

**Step 2: Init SVM:**

```
Ptr<TrainData> trainData = TrainData::create(dataMat, ROW_SAMPLE, dataLabel);
Ptr<SVM> model = SVM::create();
model->setType(SVM::C_SVC);
model->setKernel(SVM::LINEAR);
model->setC(7);
model->setNu(SVM::NU_SVC);
model->setP(0);
model->setDegree(0);
model->setGamma(20);
model->setCoef0(0);
TermCriteria term(CV_TERMCRIT_ITER +CV_TERMCRIT_EPS, 1000, 1e-6);
model->setTermCriteria(term);
model->train(trainData);
```

**Step 3: trying using SVM for predict:**

```
int i = 0;
for (i = 0; i < 15; i++) {
Mat check = dataMat.row(i);
ostringstream oss;
oss << i;
imshow(oss.str(), check.reshape(1, 128));
check = check.reshape(1, 1);
int lable = model->predict(check);
cout << "Result: " << lable << endl;
}
```

**Step 4: Result:**

```
Result: -1237234688
Result: 159407376
Result: 159407376
Result: 167908848
Result: 1065353216
Result: 1065353216
Result: 1065353216
Result: 1065353216
Result: 1065353216
Result: 1065353216
Result: 1065353216
Result: 1065353216
Result: 1065353216
Result: 1065353216
Result: 1065353216
```

As we can see, my result are very large number, although my labels are numbers in 0 to 10. I can not understand why, i think i have a mistake when I init SVM model.

But i dont know how to fix this issue, If there is any idea, please help me.

Thanks & Best Regards,

Thiep

`model`

, what do you do? Do you save your trained SVM and later load it or what? You have skipped that part. In fact, when you use`int lable = svm.predict(check);`

I see two problems: 1) I don't know where/how the`svm`

variable has been created/initialized and 2) that`svm`

is not a pointer (because you're using . instead of ->), and since you're clearly using OpenCV 3.0, something is wrong there. Please, add the initialization part that is missingI can see that some results are 1065353216. These value could be 1.0f.

Check these posts:

http://stackoverflow.com/questions/24...

http://stackoverflow.com/questions/68...