## SYNOPSIS

- 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.
- IDSFFT
- Performs smooth surface fitting when the projections of the data points in the X-Y plane are irregularly distributed in the plane.
- IDPLTR
- Plots the triangulation of the data points.
- IDGETI
- Retrieves the integer value of a Bivar parameter.
- IDGETR
- Retrieves the real value of a Bivar parameter.
- IDSETI
- Provides a new integer value for a Bivar parameter.
- IDSETR
- Provides a new real value for a Bivar parameter.

## C-BINDING SYNOPSIS

c_idbvip,c_idsfft

c_idpltr

c_idgeti

c_idgetr

c_idseti

c_idsetr

## EXAMPLES

See the example "cbex01".## ACCESS

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

## MESSAGES

When error conditions are detected, the support routine SETER is called. By default, SETER writes a message to the standard error file (as defined by I1MACH(4)) and then terminates execution. It is possible to put SETER into recovery mode and regain control after a recoverable error (which includes all of the possible errors).The possible error messages are listed below. All errors are recoverable in the sense that a user program which has called ENTSR to set recovery mode will get control back after one of these errors occurs.

IDBVIP (BIVAR) - UNCLEARED PRIOR ERROR

IDBVIP (BIVAR) - INPUT VARIABLE MD IS OUT OF RANGE

IDBVIP (BIVAR) - INPUT VARIABLE NDP IS OUT OF RANGE

IDBVIP (BIVAR) - INPUT VARIABLE NIP IS OUT OF RANGE

IDBVIP (BIVAR) - MD = 2 OR 3 BUT NDP WAS CHANGED SINCE LAST CALL

IDBVIP (BIVAR) - MD = 3 BUT ITY WAS CHANGED SINCE LAST CALL

IDBVIP (BIVAR) - MD = 3 BUT NIP WAS CHANGED SINCE LAST CALL

IDGETI (BIVAR) - UNCLEARED PRIOR ERROR

IDGETR (BIVAR) - UNCLEARED PRIOR ERROR

IDGETR (BIVAR) - INVALID KEYWORD: xxx

IDGRID (BIVAR) - INTERNAL ERROR - SEE CONSULTANT

IDPLTR (BIVAR) - UNCLEARED PRIOR ERROR

IDSETI (BIVAR) - UNCLEARED PRIOR ERROR

IDSETR (BIVAR) - UNCLEARED PRIOR ERROR

IDSETR (BIVAR) - INVALID KEYWORD: xxx

IDSFFT (BIVAR) - UNCLEARED PRIOR ERROR

IDSFFT (BIVAR) - INPUT VARIABLE MD IS OUT OF RANGE

IDSFFT (BIVAR) - INPUT VARIABLE NDP IS OUT OF RANGE

IDSFFT (BIVAR) - INPUT VARIABLE NXI OR NYI IS OUT OF RANGE

IDSFFT (BIVAR) - INPUT VARIABLE NZI IS LESS THAN NXI

IDSFFT (BIVAR) - MD = 2 OR 3 BUT NDP WAS CHANGED SINCE LAST CALL

IDSFFT (BIVAR) - MD = 3 BUT ITY WAS CHANGED SINCE LAST CALL

IDSFFT (BIVAR) - MD = 3 BUT NXI WAS CHANGED SINCE LAST CALL

IDSFFT (BIVAR) - MD = 3 BUT NYI WAS CHANGED SINCE LAST CALL

IDTANG (BIVAR) - INPUT PARAMETER NDP OUT OF RANGE

IDTANG (BIVAR) - TWO OF THE INPUT DATA POINTS ARE IDENTICAL

IDTANG (BIVAR) - ALL COLLINEAR DATA POINTS

## 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) 1987-2009University Corporation for Atmospheric Research

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