public double calculateStochasticUpdate(double[] x, double xscale, int batchSize, double gain) {
    getBatch(batchSize);
    return calculateStochasticUpdate(x, xscale, thisBatch, gain);
  }
public double calculateStochasticUpdate ( double [ ] x , double xscale , int batchSize , double gain ) { getBatch ( batchSize ) ; return calculateStochasticUpdate ( x , xscale , thisBatch , gain ) ; }
Performs stochastic update of weights x (scaled by xscale) based
on next batch of batchSize
@param x - unscaled weights
@param xscale - how much to scale x by when performing calculations
@param batchSize - number of samples to pick next
@param gain - how much to scale adjustments to x
@return value of function at specified x (scaled by xscale) for samples