NAME

       IDBVIP - produces interpolated values at points (XI(I), YI(I)), I=1,...,NIP.  This is useful for filling
       in missing data points on a grid.

SYNOPSIS

       CALL IDBVIP (MD,NDP,XD,YD,ZD,NIP,XI,YI,ZI,IWK,WK)

C-BINDING SYNOPSIS

       #include <ncarg/ncargC.h>

       void c_idbvip (int md, int ndp, float *xd, float *yd,
       float *zd, int nip, float *xi, float *yi, float *zi,
       int *iwk, float *wk)

DESCRIPTION

       MD          Mode of computation (must be 1, 2, or 3, else an error return occurs.)

                   1      If  this is the first call to this subroutine, or if the value of NDP has been changed
                          from the previous call, or if the contents of the XD or YD arrays  have  been  changed
                          from the previous call.

                   2      If  the  values  of NDP and the XD and YD arrays are unchanged from the previous call,
                          but new values for XI, YI are being used.  If MD = 2 and NDP has  been  changed  since
                          the previous call to IDBVIP, an error return occurs.

                   3      If  the  values of NDP, NIP, XD, YD, XI, YI are unchanged from the previous call, i.e.
                          if the only change on input to IDBVIP is in the ZD array.  If MD=3 and NDP or NIP  has
                          been changed since the previous call to IDBVIP, an error return occurs.

                   Between  the call with MD=2 or MD=3 and the preceding call, the IWK and WK work arrays should
                   not be disturbed.

       NDP         Number of data points (must be 4 or greater, else an error return occurs).

       XD          Array of dimension NDP containing the X coordinates of the data points.

       YD          Array of dimension NDP containing the Y coordinates of the data points.

       ZD          Array of dimension NDP containing the Z coordinates of the data points.

       NIP         The number of output points at which interpolation is to be performed (must be 1 or  greater,
                   else an error return occurs).

       XI          Array of dimension NIP containing the X coordinates of the output points.

       YI          Array of dimension NIP containing the Y coordinates of the output points.

       IWK         Integer work array of dimension at least 31*NDP + NIP.

       WK          Real work array of dimension at least 8*NDP.

       ZI          Array of dimension NIP where interpolated Z values are to be stored.

       Inadequate work space IWK and WK may may cause incorrect results.

       The  data points must be distinct and their projections in the X-Y plane must not be collinear, otherwise
       an error return occurs.

C-BINDING DESCRIPTION

       The C-binding argument descriptions are the same as the FORTRAN argument descriptions.

EXAMPLES

       To use Bivar routines, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in that
       order.

ACCESS

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

MESSAGES

       See the bivar man page for a description of all Bivar error messages and/or informational messages.

SEE ALSO

       Online: bivar, bivar_params, idsfft, idpltr, idgeti, idgetr, idseti, idsetr, ncarg_cbind

ACKNOWLEDGMENTS

       Bivar  was  written  by  Hiroshi  Akima in August 1975 and rewritten by him in late 1976.  In 1989, a new
       version of Bivar, incorporating changes described in a Rocky Mountain Journal of Mathematics was obtained
       from Dr. Akima, and included in NCAR Graphics with his permission.  In 1995, Dave  Kennison  incorporated
       the  capability  of  doing linear interpolation and a different kind of triangulation, put in a parameter
       access interface, and wrote a routine to allow the triangulation to be plotted.

COPYRIGHT

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

UNIX                                              November 1995                                   IDBVIP(3NCARG)