ncl_conran man page

CONRAN — draws a two dimensional contour map from irregularly distributed data. The contour lines may be smoothed.

Status

CONRAN is approaching obsolescence. If you have available an interpolation package which can do a random to gridded interpolation equal to that built into the Conran_family, then we recommend that you grid your dataset and use the Conpack utility instead. Refer to the conpack and conpack_params man pages as well as the NCAR Graphics Contouring and Mapping Tutorial.

Utility

This routine is part of the Conran_family in NCAR Graphics. To see the overview man page for this utility, type "man conran_family".

Synopsis

CONRAN (XD,YD,ZD,NDP,WK,IWK,SCRARR)

Description

XD
Input, real array -- of dimension NDP containing the X coordinates of the data points.
YD
Input, real array -- of dimension NDP containing the Y coordinates of the data points.
ZD
Input, real array -- of dimension NDP containing the data values at the points.
NDP
Input, integer -- is the number of data points to be contoured. NDP must be 4 or larger.
WK
Input, real array -- workspace of dimension 15*NDP.
IWK
Input, integer array -- workspace which must be dimensioned at least IWK((27+NCP)*NDP).

The parameter NCP controls the number of data points to be used in the interpolation. Increasing NCP causes more of the surrounding data to influence the point of interpolation. In the case of linear interpolation NCP is always 4. In the case of C1 interpolation, NCP can vary from 2 to 25 with 4 as the default.

The interpolation option is selected using parameter ITP. See the conran_family_params man page for a description of all internal parameters.
SCRARR
Real work array of dimension at least (RESOLUTION**2) where RESOLUTION is 40 by default.

Alternate resolutions are set using parameter SSZ. See the conran_family_params man page.

Usage

The contours will be drawn as smoothed dashed or solid lines using splines under tension. There may be characters along the lines. Many other options are available through the use of internal parameters. See the conran_family_params man page.

Quick and super versions of the Conran_family are also available through entries CONRAQ and CONRAS, respectively.

Examples

Use the ncargex command to see the relevant example tconan.

Access

CONRAN can be invoked in two different ways. The standard version produces contour plots which connect interpolated values on the boundary of the interpolation triangles. The smooth version produces contours which are smoothed using splines under tension.

To use standard CONRAN, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order. To run the smooth option an additional library, dashsmth is needed. It can be loaded by the user directly, along with the above three standard libraries, or loaded implicitly through the use of the -smooth option of the ncargf77 command. To run a code called mycode.f which has one or more calls to entry CONRAN, issue one of the commands:

NORMAL
Command: "ncargf77 mycode.f"

The contours will be drawn as unsmoothed dashed or solid lines that can include characters along the lines.
SMOOTH
Command: "ncargf77 -smooth mycode.f"

The contours will be drawn as smoothed dashed or solid lines that can include characters along the lines.

Messages

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

See Also

Online: conraq, conras, conran_family_params, conran_family, conop1, conop2, conop3, conop4, conpack, conpack_params, bivar, dashline_family, ncargf77

Hardcopy: NCAR Graphics Contouring and Mapping Tutorial; NCAR Graphics Fundamentals, UNIX Version; User's Guide for NCAR GKS-0A Graphics

Info

March 1993 UNIX NCAR GRAPHICS