cpuDeltaX
==================

.. js:function:: ConvolutionalLayer.cpuDeltaX() 

    CPUによるδxの計算

ソース
^^^^^^

.. code-block:: js

            cpuDeltaX() {
                var prev_layer = this.prevLayer;
                var num_rows_cols = this.numRows * this.numCols;
    
                var prev_y_idx = 0;
    
                // バッチ内のデータに対し
                for (var batch_idx = 0; batch_idx < miniBatchSize; batch_idx++) {
    
                    // 入力のチャネルに対し
                    for(var prev_channel_idx = 0; prev_channel_idx < prev_layer.numChannels; prev_channel_idx++){
    
                        // 入力の行に対し
                        for (var r3 = 0; r3 < prev_layer.numRows; r3++) {
    
                            // 入力の列に対し
                            for (var c3 = 0; c3 < prev_layer.numCols; c3++) {
    
                                var sum = 0.0;
    
                                // 出力のチャネルに対し
                                for(var channel_idx = 0; channel_idx < this.numChannels; channel_idx++){
                                    var delta_z_base = batch_idx * this.unitSize + channel_idx * num_rows_cols;
                                    var weight_base = (channel_idx * prev_layer.numChannels + prev_channel_idx) * this.filterSize * this.filterSize;
    
                                    // フィルターの行に対し
                                    for (var r2 = 0; r2 < this.filterSize; r2++) {
    
                                        // 出力の行
                                        var r1 = r3 - r2;
    
                                        if(0 <= r1 && r1 < this.numRows){
    
                                            // フィルターの列に対し
                                            for (var c2 = 0; c2 < this.filterSize; c2++) {
    
                                                // 出力の列
                                                var c1 = c3 - c2;
    
                                                if(0 <= c1 && c1 < this.numCols){
    
                                                    var delta_z_idx = delta_z_base + r1 * this.numCols + c1;
                                                    var weight_idx = weight_base + r2 * this.filterSize + c2;
                                                    sum += this.deltaZ.dt[delta_z_idx] * this.weight.dt[weight_idx];
                                                }
                                            }
                                        }
                                    }
                                }
    
                                this.deltaX.dt[prev_y_idx] = sum;
                                prev_y_idx++;
                            }
                        }
                    }
                }
                Assert(prev_y_idx == miniBatchSize * prev_layer.unitSize);
            }