DCL:GRPH2:UDPACK: Contour Routines: Explanation of Subroutines
Specifies all of the attributes for a contour line and sets a single contour level.
zlev (R) The value of a contour level. indx (I) The line index of a contour line. ityp (I) The line type of a contour line. clv (C*(*)) The label for the contour line. hl (R) The height of the label. (Units in VC). When hl≤0, no labels are drawn.
nlev = NumRu::DCL.udqcln().
zlev, indx, ityp, clv, hl = NumRu::DCL.udqclv(nlev).Information concerning the contour level is added as they are set by udsclv, so the values of the contour levels inquired by udqclv are not necessarily in ascending order.