NAME

       SRFACE - Draws a perspective picture of a function of two variables with hidden lines removed. The
       function is approximated by a two-dimensional array of heights.

SYNOPSIS

       CALL SRFACE (X,Y,Z,M,MX,NX,NY,S,STEREO)

C-BINDING SYNOPSIS

       #include <ncarg/ncargC.h>

       void c_srface (float *x, float *y, float *z, int *m,
       int mx, int nx, int ny, float s[6], float stereo)

DESCRIPTION

       X           A  linear  array  NX  long  containing  the  X  coordinates  of  the  points  in  the surface
                   approximation.  See "USAGE" below.

       Y           The linear array NY  long  containing  the  Y  coordinates  of  the  points  in  the  surface
                   approximation.  See "USAGE" below.

       Z           An  array  MX  by  NY  containing  the  surface  to  be  drawn  in  NX  by NY cells. Z(I,J) =
                   F(X(I),Y(J)).  See "USAGE" below.

       M           Scratch array at least 2*NX*NY words long.

       MX          First dimension of Z.

       NX          Number of data values in the X direction (the first subscript direction) in Z to be  plotted.
                   When plotting an entire array, MX=NX.

       NY          Number of data values in the Y direction (the second subscript direction) to be plotted.

       S           S  defines  the line of sight. The viewer's eye is at (S(1), S(2), S(3)) and the point looked
                   at is at (S(4), S(5), S(6)). The eye should be outside the block with opposite corners (X(1),
                   Y(1), ZMIN) and (X(NX), Y(NY), ZMAX) and the point looked at should be inside it. For a  nice
                   perspective  effect,  the  distance between the eye and the point looked at should be 5 to 10
                   times the size of the block.

       STEREO      Flag to indicate if stereo pairs are to be drawn.  0.0 means no stereo  pair  (one  picture).
                   Non-zero  means  put  out two pictures. The value of STEREO is the relative angle between the
                   eyes. A value of 1.0 produces standard separation. Negative  STEREO  reverses  the  left  and
                   right figures.

C-BINDING DESCRIPTION

       The C-binding argument descriptions are the same as the FORTRAN argument descriptions, with the following
       exceptions:

       z           An array ny by mx.

       mx          Second dimension of z.

       nx          Number of data values in the y direction (the second subscript direction) in z to be plotted.
                   When plotting an entire array, mx=nx.

       ny          Number of data values in the x direction (the first subscript direction) to be plotted.

USAGE

       • The range of Z compared with the range of X and Y determines the shape of the picture. They are assumed
         to  be in the same units and not wildly different in magnitude. S is assumed to be in the same units as
         X, Y, and Z.

       • Picture size can be made relative to distance.

       • TRN32S can be used to translate from 3 space to 2 space.

       • Data with extreme discontinuities may cause visibility errors. If this problem occurs,  use  a  distant
         eye position away from the +Z axis.

       • The  default line color is set to color index 1. If the user wishes to change the line color, he can do
         so by defining color index 1 before calling SRFACE, or by  putting  the  common  block  SRFINT  in  his
         calling program and defining and using color index ISRFMJ (defaulted to 1 in BLOCKDATA).

EXAMPLES

       Use  the  ncargex  command  to  see  the  following  relevant examples: srex01, tpwrzs, tsrfac, fsrpwrzs,
       fsrsrfac.

ACCESS

       To use SRFACE or c_srface, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably  in
       that order.

SEE ALSO

       Online: surface, surface_params, ezsrfc, pwrzs, setr, ncarg_cbind.

       Hardcopy: NCAR Graphics Fundamentals, UNIX Version

COPYRIGHT

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research
       The use of this Software is governed by a License Agreement.

UNIX                                               March 1993                                     SRFACE(3NCARG)