about the negative node selection in triplets samples

[Junsong-Wang]

In your triplets sampling layer, you will firstly select the <anchor, positive>, when to find the best negative to form the triplets, but I see in your code(https://github.com/tyandzx/caffe/blob/master/src/caffe/layers/sample_triplet_layer.cpp#L48), you will select the negative node that is most far from the anchor, not the closest one (hardest negative) or using semi-hardest negative proposed in FaceNet, like

What is your considerations? thanks.

[Junsong-Wang]

I see, the author use cosine distance, not the Euler distance.