code: public DMatrixRMaj next( DMatrixRMaj x )
  	{
  		for( int i = 0; i < r.numRows; i++ ) {
  			r.set(i,0,rand.nextGaussian());
  		}
  		x.set(mean);
  
  		multAdd(A,r,x);
  
  		return x;
  	}
docs: Makes a draw on the distribution and stores the results in parameter 'x'