public static double[] getCol(double[][] m1, int col) {
    double[] ret = new double[m1.length];
    for(int i = 0; i < ret.length; i++) {
      ret[i] = m1[i][col];
    }
    return ret;
  }
public static double [ ] getCol ( double [ ] [ ] m1 , int col ) { double [ ] ret = new double [ m1 . length ] ; for ( int i = 0 ; i < ret . length ; i ++ ) { ret [ i ] = m1 [ i ] [ col ] ; } return ret ; }
Get a column from a matrix as vector.

@param m1 Matrix to extract the column from
@param col Column number
@return Column