CONREC(3NCARG)

NAME
CONREC - draws a two dimensional contour map from data stored in a rectangular array. The contour lines are labeled.

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

STATUS
CONREC is obsolete. It has been superseded by the contouring package, Conpack. See the Conpack entry CPCNRC for a simple CONREC replacement. For more complex examples refer to the conpack and conpack_params man pages as well as the NCAR Graphics Contouring and Mapping Tutorial.

CONREC continues to be provided for compatibility of early NCAR Graphics codes. If you are writing new code, we suggest that you use the more general and rigorous Conpack contouring package. All CONREC options can be duplicated by the proper selection of Conpack parameters.

SYNOPSIS
CALL CONREC(Z,L,M,N,FLO,HI,FINC,NSET,NHI,NDOT) - draws a contour map using options specified as input arguments.

DESCRIPTION

Z   (an input array of type REAL) defining a two-dimensional field to be contoured. A subset of Z of extent M by N can be contoured.

L   (an input parameter of type INTEGER) which is the first dimension of the Z array.

M   (an input parameter of type INTEGER) which is the extent of the first dimension of array Z to be contoured. This allows for a sub-array of Z to be contoured. M must be less than or equal to L.

N   (an input parameter of type INTEGER) which is the extent of the second dimension of array Z to be contoured. This allows for a sub-array of Z to be contoured. N must be less than or equal to the second dimension of Z.

FLO (an input parameter of type REAL) defining a lowest level for contouring. If FLO = HI = 0., a value rounded up from the minimum value of Z will be generated by CONREC.

HI  (an input parameter of type REAL) defining a highest level for contouring. If HI = FLO = 0., a value rounded down from the maximum value of Z will be generated by CONREC.

FINC
    (an input parameter of type REAL) which defines how the contour levels are to be selected.

    > 0., use this value for the increment between contour levels. There will be (HI-FLO)/FINC contour lines generated.

    = 0., causes CONREC to generate a value which will result in between 10 and 30 contours.

    < 0., the number of contour levels is the integer absolute value of this number (FINC.)

NSET
    (an input parameter of type INTEGER) which controls plot scaling according to:

    = 0, CONREC automatically sets the window and viewport sizes. The viewport becomes by default .05 to .95 in the larger dimension (M or N), and .05 to a proportionately smaller number in the smaller dimension. The window becomes 1. to FLOAT(M) in X, and 1. to FLOAT(N) in Y. The PERIM entry of the Gridall utility is called to generate a plot boundary with tick marks placed at the data grid points.

    > 0, CONREC assumes the window and viewport have been set by the user. No plot boundary is drawn.

    < 0, CONREC uses the existing viewport and sets the window to 1. to FLOAT(M) in X, and 1. to FLOAT(N) in Y. No plot boundary is drawn.

NHI (an input parameter of type INTEGER) which controls the printing of extra information on the plot.

    = 0, Symbols H and L are written where highs and lows occur and the value of the high or low is written under the symbol.

    > 0, The Z data values are printed, centered at each grid point.

    < 0, Neither of the above is done.

NDOT
    (an input parameter of type INTEGER) which specifies the line patterns to be used in drawing the contours. Only the last 10 binary bits of NDOT are used in creating a binary pattern is which 0's are no-line and 1's are line segments. If the absolute value of NDOT is 0, 1, or 1023 a solid line is drawn. 1023 in decimal converts to 1777 octal, or 1111111111 in binary.

    > 0, The NDOT pattern is used to draw all contours.

    < 0, The absolute value of NDOT is used for negative-valued contours and solid lines are drawn for positive contours.

EXAMPLES
Use the ncargex command to see the relevant examples tconre, tcnqck, tcnsmt, and tcnsup.

ACCESS
CONREC can be invoked in four different ways to create contour plots which vary considerably in appearance. The four variations include quick, normal, smooth, and super contour lines. This progression represents a tradeoff between speed of computation and the appearance of the contour plots. These variations are specified through selected command line options of the ncargf77 command.

To use CONREC, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order. Other optional libraries to create the quick, smooth, and super contours will automatically be linked by the ncargf77 command. To run a code called mycode.f which has one or more calls to entry CONREC, 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.

QUICK
    Command: "ncargf77 -quick mycode.f"

    The contours will be drawn as unsmoothed dashed or solid lines without characters along the lines. The QUICK drawing algorithm is faster and cruder than that used for NORMAL contour lines. QUICK uses a cell-by-cell analysis rather than following each contour line to completion in sequence as is done in the NORMAL algorithm.

SMOOTH
    Command: "ncargf77 -smooth mycode.f"

    The contours will be drawn as smoothed dashed or solid lines using splines under tension. There may be characters along the lines.

SUPER
    Command: "ncargf77 -super mycode.f"

    The contours will be drawn as smoothed dashed or solid lines using splines under tension. There may be characters along the lines. Crowded lines can be thinned.

MESSAGES
When error conditions are detected, the support routine SETER is called in such a way that it writes a message to the standard error file (as defined by I1MACH(4)) and then terminates execution. The possible error messages are as follows:

CONREC - DIMENSION ERROR - M*N .GT. (2**IARTH)
The array to be contoured is dimensioned M by N. This is larger than the address space on this computer (2**IARTH) where IARTH is the size of an address integer. Check your dimension sizes.

SEE ALSO
Online: ezcntr, conrec_family_params, conrec_family, conpack, conpack_params, cpcnrc, gridall, dashline_family, ncargf77

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

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