Assign different learning rate for a layer

lr_per_layer.lua

-- suppose you have a model called model
lrs_model = model:clone()
lrs = lrs_model:getParameters()
lrs:fill(1) -- setting the base learning rate to 1

-- now lets set the learning rate factor of the bias of module 5 to 2
lrs_model:get(5).bias:fill(2)
-- same thing for the weights of module 2, let's set them to 3
lrs_model:get(2).weight:fill(3)

-- now pass lrs_model to optimState, which was created previously
optimState.learningRates = lrs