What is the sigmoid function , and what is its use in machine learning 's neural networks ?
In machine learning algorithms , why is sigmoid function used primarily and not functions like tanh -LRB- x -RRB- ? In tanhx for eg . seem to split y-axis evenly and flatten out fast as x approaches + / - infinity . The range being : sigmoid -LSB- 0-1 -RSB- and tanh -LRB- x -RRB- -LSB- -1,1 -RSB- .