ncl_velvec(3)

1VELVEC(3NCARG)                   NCAR GRAPHICS                  VELVEC(3NCARG)
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NAME

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

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

15       VELVEC is obsolete, and is supported only to provide compatibility with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

23       #include <ncarg/ncargC.h>
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25       void c_velvec(float *u, int lu, float *v, int lv, int m,
26                     int n, float flo, float hi, int nset,
27                     int ispv, float *spv)
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DESCRIPTION

30       U           (REAL 2-dimensional array, dimensioned LU x n: n >= N,
31                   input): By default, assumed to contain the first
32                   dimensional Cartesian components of the vector field.
33                   However, if PLR is non-zero, it is treated as containing
34                   the vector magnitudes.
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36       LU          (INTEGER, input): Actual value of the first dimension of
37                   array U.
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39       V           (REAL 2-dimensional array, dimensioned LV x n: n >= N,
40                   input): By default, assumed to contain the second
41                   dimensional Cartesian components of the vector field.
42                   However, if PLR is non-zero, it is treated as containing
43                   the vector angles.
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45       LV          LV (INTEGER, input): Actual value of the first dimension of
46                   array V.
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48       M           (INTEGER, input): Number of contiguous elements along the
49                   first dimensional axis containing data to be processed in
50                   each of the arrays, U and V.
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52       N           (INTEGER, input): Number of contiguous elements along the
53                   second dimensional axis containing data to be processed in
54                   each of the arrays, U and V.
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56       FLO         (REAL, input): Minimum vector magnitude allowed to be
57                   displayed in the plot.
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59       HI          (REAL, input): Maximum vector magnitude allowed to be
60                   displayed in the plot. If set to 0.0 there is no upper
61                   limit imposed.
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63       NSET        (INTEGER, input): Flag that controls how and when the SET
64                   call is invoked. If NSET is 0, VELVEC makes a SET call to
65                   establish a standard viewport and window boundaries
66                   coincident with the array coordinate boundaries. PERIM is
67                   called to draw a border. If NSET is greater than zero,
68                   VELVEC does not call SET or PERIM. If NSET is less than
69                   zero, VELVEC calls SET to establish window boundaries
70                   coincident with the array grid coordinate boundaries but
71                   does not modify the viewport or call PERIM. Unlike the
72                   VVINIT/VVECTR interface, when VELVEC does a SET call, it
73                   always restores the original coordinate system state before
74                   returning.
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76       ISPV        (INTEGER, input): Flag to control the special value
77                   feature. 0 means that the feature is not in use. 1 means
78                   that if the value of U(I,J)=SPV(1) the vector will not be
79                   plotted.  2 means that if the value of V(I,J)=SPV(2) the
80                   vector will not be plotted. 3 means that if either
81                   U(I,J)=SPV(1) or V(I,J)=SPV(2) then the vector will not be
82                   plotted. 4 means that if U(I,J)=SPV(1) and V(I,J)=SPV(2),
83                   the vector will not be plotted.
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85       SPV         (REAL array, dimensioned 2, input): An array of length 2
86                   which gives the value in the U array and the value in the V
87                   array which denote special values. This argument is ignored
88                   if ISPV=0. The default values are 1.0E12.
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C-BINDING DESCRIPTION

91       The C-binding argument descriptions are the same as the FORTRAN
92       argument descriptions with the following exceptions:
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95       lu          The second dimension of u in the calling program.
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97       lv          The second dimension of v in the calling program.
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99       m           Number of contiguous elements along the second dimensional
100                   axis containing data to be processed in each of the arrays,
101                   u and v.
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103       n           Number of contiguous elements along the first dimensional
104                   axis containing data to be processed in each of the arrays,
105                   u and v.
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USAGE

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

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

121       Copyright (C) 1987-2009
122       University Corporation for Atmospheric Research
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124       The use of this Software is governed by a License Agreement.
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128UNIX                              April 1993                    VELVEC(3NCARG)