code: public static void fill(DMatrixD1 a, double value)
      {
          Arrays.fill(a.data, 0, a.getNumElements(), value);
      }
docs: <p>
  Sets every element in the matrix to the specified value.<br>
  <br>
  a<sub>ij</sub> = value
  <p>
  
  @param a A matrix whose elements are about to be set. Modified.
  @param value The value each element will have.