NAME

       VELVEC - A older version of the Vectors utility, now a front-end to VELVCT. It is identical to the VELVCT
       call except that there is no LENGTH parameter to allow adjustment of the realized length of the maximum
       vector magnitude.

SYNOPSIS

       VELVEC (U,LU,V,LV,M,N,FLO,HI,NSET,ISPV,SPV)

STATUS

       VELVEC is obsolete, and is supported only to provide compatibility with old NCAR Graphics codes. However,
       the compatibility mode parameter, CPM, offers a number of options to help ease the the transition to the
       new version of the utility. When writing new code you are encouraged not to use this entry point, since
       it provides less capability than the standard Vectors interface, and may eventually be phased out.

C-BINDING SYNOPSIS

       #include <ncarg/ncargC.h>

       void c_velvec(float *u, int lu, float *v, int lv, int m,
                     int n, float flo, float hi, int nset,
                     int ispv, float *spv)

DESCRIPTION

       U           (REAL 2-dimensional array, dimensioned LU x n: n >= N, input): By default, assumed to contain
                   the  first dimensional Cartesian components of the vector field. However, if PLR is non-zero,
                   it is treated as containing the vector magnitudes.

       LU          (INTEGER, input): Actual value of the first dimension of array U.

       V           (REAL 2-dimensional array, dimensioned LV x n: n >= N, input): By default, assumed to contain
                   the second dimensional Cartesian components of the vector field. However, if PLR is non-zero,
                   it is treated as containing the vector angles.

       LV          LV (INTEGER, input): Actual value of the first dimension of array V.

       M           (INTEGER, input): Number of contiguous elements along the first dimensional  axis  containing
                   data to be processed in each of the arrays, U and V.

       N           (INTEGER,  input): Number of contiguous elements along the second dimensional axis containing
                   data to be processed in each of the arrays, U and V.

       FLO         (REAL, input): Minimum vector magnitude allowed to be displayed in the plot.

       HI          (REAL, input): Maximum vector magnitude allowed to be displayed in the plot. If  set  to  0.0
                   there is no upper limit imposed.

       NSET        (INTEGER,  input):  Flag  that  controls  how and when the SET call is invoked. If NSET is 0,
                   VELVEC makes a SET call to establish a standard viewport  and  window  boundaries  coincident
                   with  the  array  coordinate boundaries. PERIM is called to draw a border. If NSET is greater
                   than zero, VELVEC does not call SET or PERIM. If NSET is less than zero, VELVEC calls SET  to
                   establish window boundaries coincident with the array grid coordinate boundaries but does not
                   modify the viewport or call PERIM. Unlike the VVINIT/VVECTR interface, when VELVEC does a SET
                   call, it always restores the original coordinate system state before returning.

       ISPV        (INTEGER,  input): Flag to control the special value feature. 0 means that the feature is not
                   in use. 1 means that if the value of U(I,J)=SPV(1) the vector will not be plotted.   2  means
                   that  if  the  value  of V(I,J)=SPV(2) the vector will not be plotted. 3 means that if either
                   U(I,J)=SPV(1) or V(I,J)=SPV(2) then  the  vector  will  not  be  plotted.  4  means  that  if
                   U(I,J)=SPV(1) and V(I,J)=SPV(2), the vector will not be plotted.

       SPV         (REAL array, dimensioned 2, input): An array of length 2 which gives the value in the U array
                   and the value in the V array which denote special values. This argument is ignored if ISPV=0.
                   The default values are 1.0E12.

C-BINDING DESCRIPTION

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

       lu          The second dimension of u in the calling program.

       lv          The second dimension of v in the calling program.

       m           Number of contiguous elements along  the  second  dimensional  axis  containing  data  to  be
                   processed in each of the arrays, u and v.

       n           Number  of  contiguous  elements  along  the  first  dimensional  axis  containing data to be
                   processed in each of the arrays, u and v.

USAGE

       VELVEC is used identically to VELVCT except that there is no provision for adjusting the realized  length
       of the maximum vector magnitude. See the velvct man page for more information.

ACCESS

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

SEE ALSO

       Online: vectors, vectors_params, fx, vvectr, vvgetc, vvgeti,  vvgetr,  vvinit,  vvrset,  vvsetc,  vvseti,
       vvsetr, vvudmv, vvumxy, ncarg_cbind.

COPYRIGHT

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research

       The use of this Software is governed by a License Agreement.

UNIX                                               April 1993                                     VELVEC(3NCARG)