code: public static DMatrixRMaj symmetric(int length, double min, double max, Random rand) {
          DMatrixRMaj A = new DMatrixRMaj(length,length);
  
          symmetric(A,min,max,rand);
  
          return A;
      }
docs: Creates a random symmetric matrix whose values are selected from an uniform distribution
  from min to max, inclusive.
  
  @param length Width and height of the matrix.
  @param min Minimum value an element can have.
  @param max Maximum value an element can have.
  @param rand Random number generator.
  @return A symmetric matrix.