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CONREC is obsolete. It has been superseded by the contouring package, Conpack.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.