subtract output of two layers

[Peter Neher]

Hi everyone,

I was wondering if this is the right way to get the difference-vector of the output vectors of two fully connected layers:

layer
{
  name: "eltwise_layer"
  type: "Eltwise"
  bottom: "ip1"
  bottom: "ip2"
  top: "diff"
  eltwise_param {
    operation: SUM
    coeff: -1
  }
}

Cheers,
Peter

[Evan Shelhamer]

​That's almost it, but you need to set a coefficient for each bottom. Try

layer 
{
  name: "eltwise_layer"
  type: "Eltwise"
  bottom: "ip1"
  bottom: "ip2"
  top: "diff"
  eltwise_param {
    operation: SUM

    coeff: 1
    coeff: -1
  }

}​

to compute ip1 - ip2.

Evan Shelhamer

[Peter Neher]

Seems to work, thank you!