nb_vignettes = THLongTensor_size(labels, 0);
m = THLongTensor_storage(labels)->data + THLongTensor_storageOffset(labels);
st0 = THLongTensor_stride(labels, 0);
nb_vignettes = THLongTensor_size(labels, 0);
m = THLongTensor_storage(labels)->data + THLongTensor_storageOffset(labels);
st0 = THLongTensor_stride(labels, 0);