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SUBROUTINE CONOR (Z1,ZE,Z2, MX,MY, NX,NY, NZ, PL2OR3)
C$ (Orthogonal Relief)
C$ The technique of orthogonal relief requires some
C$ explanation. It was introduced into map-making by K.
C$ Tanaka whose articles below may be consulted for further
C$ information. The basic idea is to give contour plots
C$ shading as if from side lighting to improve the impression
C$ of depth in a map. The use of this routine must be
C$ combined with an ordinary contour map, as produced by CONCA
C$ for example.
C$
C$ Best results are obtained if the orthogonal relief contours
C$ are plotted densely (100-200, depending on the surface),
C$ and in a different color than the ordinary contours. The
C$ large number of contours required make this routine rather
C$ expensive to use.
C$
C$ The arguments are:
C$
C$ (MX,MY)........Actual declared dimension of ZE(*,*).
C$ ZE(NX,NY)......Array to be contoured.
C$ (Z1,Z2)........Contouring interval.
C$ NZ.............Number of contour levels for the interval
C$ Z1..Z2. The number actually drawn is
C$ 3*(NZ-1) + 1, and contours are drawn at
C$ equal intervals from Z1 - DELTA(Z) to Z2 +
C$ DELTA(Z), where DELTA(Z) = Z2 - Z1, for a
C$ total interval of 3*DELTA(Z). The larger
C$ interval is essential, since the surface is
C$ tilted.
C$ PL2OR3.........2-D or 3-D pen movement subroutine, perhaps
C$ PL2CA or PL3CA. If 3-D plotting is in
C$ effect (set via CALL SET3D (.TRUE.)), the
C$ 3-D version must be used. Otherwise the 2-D
C$ version is required.
C$
C$ References: K. Tanaka, Geographical Review, 40, 444-456 (1950),
C$ Geographical Journal,79, 213-219 (1932).
C$ T.M. Oberlander, Annals of the Association of
C$ American Cartographers, 58, 802-813 (1968).
C$
C$ (13-FEB-85)