install.packages('keras')x in train phase, and alt otherwise.axis.indices in the tensor reference.x in test phase, and alt otherwise.axis.R tensors into a rank R+1 tensor.targets are in the top k predictions.x to zero at random, while scaling the entire tensor.x is a Keras tensor.x is a placeholder.variables w.r.t. loss.message and the tensor value when evaluated.x to new_x.x by adding increment.variables but with zero gradient w.r.t. every other variable.x by subtracting decrement.x by n.