get_partial_conv2d_input Function

  function get_partial_conv2d_input(this, upstream_grad) result(output)
    !! Get partial derivative wrt input for 2D convolution
    implicit none

    class(array_type), intent(inout) :: this
    type(array_type), intent(in) :: upstream_grad
    type(array_type) :: output

    call output%allocate(array_shape = [ this%left_operand%shape, &
         size(this%left_operand%val, dim=2) ])
    call this%get_partial_left_val(upstream_grad%val, output%val)

  end function get_partial_conv2d_input