Previous: hidpv Up: ../plot79_h.html Next: hidrvs


HIDRV

       SUBROUTINE  HIDRV (Z0, Z1,ZE,Z2, MX,MY, NX,NY, LX,LY, S, ROT, PL2)
 C$    (Rotated View)
 C$    Produce a parallel  projection drawing  of a  single-valued
 C$    function defined in Cartesian coordinates, exhibiting  arcs
 C$    on the  surface  parallel  to  the  coordinate  axes.   For
 C$    greater variety in presentation,  the entire figure may  be
 C$    rotated through  an angle,  which  should be  specified  in
 C$    degrees.   The  scale  of   the  drawing  is  adjusted   to
 C$    approximately fill  the frame,  and thus  depends upon  the
 C$    rotation angle chosen.  The arguments are:
 C$
 C$    Z0......Cutoff value.  Only function values, ZE(I,J), above
 C$            (S .GT. 0.0) or below (S .LT. 0) Z0 are visible.
 C$    ZE......Array containing the surface.  ZE(I,J) =
 C$            F(X(I),Y(J)).
 C$    Z1,Z2...Span of surface values.
 C$    MX,MY...Actual declared dimensions of the array ZE(*,*).
 C$    NX,NY...Sections of ZE(*,*) actually used.
 C$    LX,LY...Increments in X and Y directions (.GT. 0).  Values
 C$            of LX and LY larger  than 1 produce a coarser  mesh
 C$            on the drawing without losing the smoothness of the
 C$            complete surface.  LX should be an integral divisor
 C$            of NX-1, and LY of NY-1.  If this is not the  case,
 C$            the  next  smallest  value  which  satisfies   this
 C$            requirement is used internally.
 C$    S.......=+1.0, graph positive part of function,
 C$            =-1.0, graph negative part of function,
 C$            = 0.0, graph both positive and negative parts.
 C$            If S = 0.0, the cutoff value Z0 has no effect.
 C$    ROT.....Angle  of  rotation  in  degrees.   Positive angles
 C$            correspond to looking down the positive Z axis in a
 C$            right-handed   coordinate   system   and   rotating
 C$            counterclockwise.   Rotation   angles   which   are
 C$            multiples of 90 degrees, or  within a degree or  so
 C$            of such a number, should be avoided, since drawings
 C$            then  deteriorate  because  of  the  way  the  scan
 C$            algorithm in the hidden line routine works.
 C$    PL2.....2-D pen movement subroutine, usually PL2CA
 C$
 C$    (04-FEB-82)