init
========

.. js:function:: ConvolutionalLayer.init(prev_layer) 

    初期処理

    :param Layer prev_layer: 直前のレイヤー 

ソース
^^^^^^

.. code-block:: js

            init(prev_layer) {
                super.init(prev_layer);
    
                this.numRows = this.prevLayer.numRows - this.filterSize + 1;
                this.numCols = this.prevLayer.numCols - this.filterSize + 1;
                this.unitSize = this.numChannels * this.numRows * this.numCols;
    
                this.bias = new ArrayView(this.numChannels);
                for (var i = 0; i < this.bias.dt.length; i++) {
                    this.bias.dt[i] = random.randn();
                }
    
                this.weight = new ArrayView(this.numChannels, prev_layer.numChannels, this.filterSize, this.filterSize);
                for (var i = 0; i < this.weight.dt.length; i++) {
                    this.weight.dt[i] = random.randn();
                }
    
                if(this.activationFunction == ActivationFunction.ReLU){
                    var sd = Math.sqrt(2.0 / prev_layer.unitSize);
                    for(var i = 0; i < this.weight.dt.length; i++){
                        this.weight.dt[i] *= sd;
                    }
                }
    
                this.deltaBias    = new ArrayView(this.numChannels);
                this.deltaWeight   = new ArrayView(this.numChannels, prev_layer.numChannels, this.filterSize, this.filterSize);
            }