pascal_row_2D Function

  pure function pascal_row_2D(N, x, y) result(row)
      !*
      ! Generates a row of Pascal's triangle in 2D
      !
      ! Pascal's triangle in 2D looks like this:
      !   \[ [1] \]
      !   \[ [x,~ y] \]
      !   \[ [x^2,~ x y,~ y^2] \]
      !   \[ [x^3,~ x^2y,~ xy^2,~ y^3] \]
      !   \[ [x^4,~ x^3y,~ x^2y^2,~ xy^3, y^4] \]
      !   \[ \vdots \]
      !   \[ [x^N,~ x^{N-1}y,~ \cdots,~ xy^{N-1},~ y^N] \]
      !
      ! The rows are zero-indexed, therefore, the third row (index=2)
      ! would be \[x^2, x\cdot y, y^2\]

      integer,  intent(in)      :: N    !! Row number of pascal's 2D triange (0-indexed)
      real(wp), intent(in)      :: x    !! X-value used in triange
      real(wp), intent(in)      :: y    !! Y-Value used in triange
      real(wp), dimension(N+1)  :: row  !! Output row of triange

      integer :: ii

      ! Produces the elements of an array: [x^N, x^(N-1)*y, x^(N-2)*y^2, ..., y^N]
      row = [( x**(N-ii) * y**(ii), ii = 0, N )]

      return
  end function pascal_row_2D