program volatile_doctest use vecfor_R4P type(vector_R4P) :: pt(0:3) pt(0) = 1 * ex_R4P + 2 * ey_R4P + 5.3 * ez_R4P pt(1) = ex_R4P pt(2) = ey_R4P pt(3) = ex_R4P - ey_R4P pt(0) = projection_onto_plane_R4P(pt(0), pt1=pt(1), pt2=pt(2), pt3=pt(3)) print "(3(F3.1,1X))", pt(0)%x, pt(0)%y, pt(0)%z endprogram volatile_doctest