示例#1
0
        public WeightMatrix Dropout(WeightMatrix V, bool[] droppedMask)
        {
            var res = new WeightMatrix(V.Rows, V.Columns, 0);
            var N   = V.Weight.Length;
            var V2  = V.Clone();

            for (var i = 0; i < N; i++)
            {
                if (droppedMask[i])
                {
                    V2.Weight[i] = 0;
                }                                          // drop!
            }

            res = V2;


            if (this.needs_backprop)
            {
                Action backward = () =>
                {
                    var chain_grad = res;
                    V.Gradient = new double[N]; // zero out gradient wrt data
                    for (var i = 0; i < N; i++)
                    {
                        if (!(droppedMask[i]))
                        {
                            V.Gradient[i] += chain_grad.Gradient[i]; // copy over the gradient
                        }
                    }
                };
                this.backprop.Add(backward);
            }
            return(res);
        }
示例#2
0
        public WeightMatrix Dropout(WeightMatrix V, double drop_prob)
        {
            var res = new WeightMatrix(V.Rows, V.Columns, 0);
            var N   = V.Weight.Length;

            bool[] dropped = new bool[V.Rows * V.Columns];
            var    V2      = V.Clone();

            for (var i = 0; i < N; i++)
            {
                if (ra.NextDouble() < drop_prob)
                {
                    V2.Weight[i] = 0; dropped[i] = true;
                }                                                                             // drop!
                else
                {
                    dropped[i] = false;
                }
            }

            res = V2;


            if (this.needs_backprop)
            {
                Action backward = () =>
                {
                    var chain_grad = res;
                    V.Gradient = new double[N]; // zero out gradient wrt data
                    for (var i = 0; i < N; i++)
                    {
                        if (!(dropped[i]))
                        {
                            V.Gradient[i] += chain_grad.Gradient[i]; // copy over the gradient
                        }
                    }
                };
                this.backprop.Add(backward);
            }
            return(res);
        }