question: public static Complex [ ] convolve ( Complex [ ] x , Complex [ ] y ) { Complex [ ] a = new Complex [ 2 * x . length ] ; for ( int i = 0 ; i < x . length ; i ++ ) a [ i ] = x [ i ] ; for ( int i = x . length ; i < 2 * x . length ; i ++ ) a [ i ] = ZERO ; Complex [ ] b = new Complex [ 2 * y . length ] ; for ( int i = 0 ; i < y . length ; i ++ ) b [ i ] = y [ i ] ; for ( int i = y . length ; i < 2 * y . length ; i ++ ) b [ i ] = ZERO ; return cconvolve ( a , b ) ; }
target:  Returns the linear convolution of the two specified complex arrays.