/// <summary>
///
/// </summary>
/// <param name="input"></param>
/// <param name="innerGraph"></param>
/// <returns></returns>
public WeightMatrix Step(WeightMatrix input, ComputeGraph innerGraph)
{
var hidden_prev = ht;
var cell_prev = ct;
var cell = this;
var h0 = innerGraph.mul(input, cell.Wix);
var h1 = innerGraph.mul(hidden_prev, cell.Wih);
var input_gate = innerGraph.sigmoid(
innerGraph.add(
innerGraph.add(h0, h1),
cell.bi
)
);
var h2 = innerGraph.mul(input, cell.Wfx);
var h3 = innerGraph.mul(hidden_prev, cell.Wfh);
var forget_gate = innerGraph.sigmoid(
innerGraph.add(
innerGraph.add(h2, h3),
cell.bf
)
);
var h4 = innerGraph.mul(input, cell.Wox);
var h5 = innerGraph.mul(hidden_prev, cell.Woh);
var output_gate = innerGraph.sigmoid(
innerGraph.add(
innerGraph.add(h4, h5),
cell.bo
)
);
var h6 = innerGraph.mul(input, cell.Wcx);
var h7 = innerGraph.mul(hidden_prev, cell.Wch);
var cell_write = innerGraph.tanh(
innerGraph.add(
innerGraph.add(h6, h7),
cell.bc
)
);
// compute new cell activation
var retain_cell = innerGraph.eltmul(forget_gate, cell_prev); // what do we keep from cell
var write_cell = innerGraph.eltmul(input_gate, cell_write); // what do we write to cell
var cell_d = innerGraph.add(retain_cell, write_cell); // new cell contents
// compute hidden state as gated, saturated cell activations
var hidden_d = innerGraph.eltmul(output_gate, innerGraph.tanh(cell_d));
this.ht = hidden_d;
this.ct = cell_d;
return(ht);
}