Hello everyone,

I am trying to copy convolutional layer weights to a std::vectorcv::Mat structure using this function:

```
void tensor2mat(torch::Tensor &t, std::vector<cv::Mat> &out)
{
caffe2::TypeMeta dtype;
dtype = t.dtype();
c10::ScalarType type;
type = t.scalar_type();
std::cout << "Tensor Format: {dims} ( depth - type)" << std::endl;
std::cout << t.sizes() << " ( " << dtype << " - " << type << " )" << std::endl;
int mattype = CV_8U;
int typesize;
if (dtype == torch::kInt64 || dtype == torch::kFloat64)
{
typesize = sizeof(int64);
mattype = CV_64F;
}
else if (dtype == torch::kFloat32)
{
typesize = sizeof(float);
mattype = CV_32F;
}
else if (dtype == torch::kByte || dtype == torch::kChar)
{
typesize = sizeof(char);
mattype = CV_8U;
}
if (t.dim() == 4)
{
// if number of dimensions is 4
// NBatch x NChannels x H x W
out.clear();
out.resize(t.size(0));
for (size_t i = 0; i < out.size(); i++) {
std::vector<cv::Mat> channels(t.size(1));
for (size_t j = 0; j < t.size(1); j++)
{
// Iterate through channels
torch::Tensor one_plane_tensor = t[i][j];
// one_plane_tensor shape is [ 11, 11 ]
std::cout << one_plane_tensor.sizes() << " depth: " << one_plane_tensor.dtype() << std::endl;
one_plane_tensor.to(torch::kCPU);
// one_mat is CV_32FC1
cv::Mat one_mat(one_plane_tensor.size(0), one_plane_tensor.size(1), CV_MAKETYPE(mattype,1));
// here I get an error
std::memcpy((void *)one_mat.data, one_plane_tensor.data_ptr(), typesize * one_plane_tensor.numel());
channels[j] = one_mat;
}
cv::merge(channels, out[i]);
}
// Create a grid with displaying all the images in the vector
cv::Mat output = ext::draw::composeLayerImage(std::pair < std::string, std::vector<cv::Mat> >("prueba", imgs), true);
}
}
```

Layer’s weight tensor shape is [64, 3, 11, 11] so the output vector should contain 64 11x11x3 images, so that I can display the content of the weights in a window.

ComposeLayer is just a function to visualize all the images in a grid.

I call the function in this way

```
cv::Mat prueba;
// tensor2mat(net->conv1.get()->weight, prueba);
tensor2mat(net->conv1.get()->named_parameters()["weight"], prueba);
```

When I call it, an error is produced in memcpy instruction. Could anyone give me a hint as to why this is happening?

Thank you very much.