Plotter Address Units (PAUs) and Metacode Units (MUs) are no
longer used in NCAR Graphics; thus, all functions with either an M or a P as
the second or third letter of the function name are considered obsolete.
The current recognized coordinate systems are GKS world
coordinates, GKS normalized device coordinates, NCAR Graphics fractional
coordinates, and NCAR Graphics user coordinates. See the NCAR Graphics
document "NCAR Graphics Fundamentals, UNIX Version" for
descriptions of these coordinate systems.
The following definitions of the PAU coordinate system and the MU
coordinate system are provided for the purpose of interpreting and
converting codes which use PAUs or MUs:
The plotter coordinates of a point are integers IPX and IPY, where
IPX is between 1 and 2**MX and IPY is between 1 and 2**MY. MX and MY are
internal parameters of SPPS; each has a default value of 10. Values of MX
and MY can be set by calling the routines SETI or SETUSV and retrieved by
calling the routines GETSI or GETUSV.
The metacode coordinates of a point are integers IMX and IMY
between 0 and 32767 inclusive. The area addressed is a square in a
"metacode space" that is usually mapped into a square subset of
the addressable area of the plotting device. Metacode coordinates were used
in calls to the routine PLOTIT and are returned in calls to FL2INT.
Current:
X = CFUX (RX), Y = CFUY(RY)
X = CUFX (RX), Y = CUFY(RY)
Obsolete:
X = CMUX (IX), Y = CMUY(IY)
X = CPUX (IX), Y = CPUY(IY)
X = CMFX (IX), Y = CMFY(IY)
X = CPFX (IX), Y = CPFY(IY)
I = KFMX (RX), J = KFMY(RY)
I = KUMX (RX), J = KUMY(RY)
I = KFPX (RX), J = KFPY(RY)
I = KUPX (RX), J = KUPY(RY)
I = KPMX (IX), J = KPMY(IY)
I = KMPX (IX), J = KMPY(IY)
#include <ncarg/ncargC.h>
float c_cfux (float rx)
float c_cfuy (float ry)
float c_cufx (float rx)
float c_cufy (float ry)
- RX
- (an input expression of type REAL) is an X coordinate in the coordinate
system specified by the second letter of the function name. In a reference
to CFUX, RX is a fractional X coordinate; in a reference to CUFX, RX is a
user X coordinate.
- RY
- (an input expression of type REAL) is a Y coordinate in the coordinate
system specified by the second letter of the function name. In a reference
to CFUY, RY is a fractional Y coordinate; in a reference to CUFY, RY is a
user Y coordinate.
IX and IY occur as arguments only in references to some of the
obsolete functions; they represent input expressions of type INTEGER,
specifying the X and Y coordinates of a point in either PAUs or MUs
(depending on the second letter of the function name).
The first letter of the function name is a C if the result is of
type REAL and a K if the result is of type INTEGER (the latter only happens
for some of the obsolete ones). This conforms to the usual FORTRAN
convention for implicit typing.
The second letter of the function name specifies the coordinate
system of the argument.
The third letter of the function name specifies the coordinate
system of the functional result. In references to CFUX and CFUY, the result
is in the user system; in references to CUFX and CUFY, the result is in the
fractional system.
The fourth letter of the function name is an X or a Y, depending
on whether an X or a Y coordinate is being converted.
The C-binding argument description is the same as the FORTRAN
argument description.
Use the ncargex command to see the following relevant examples
which use coordinate converters: mpex10, cbex01, sfex02, epltch.
The command "ncargex -n mpex10" will load the driver
mpex10.f into your current working directory where you can examine the file
using a local editor, or the UNIX more command.
There were 24 conversion functions in the original set. These
functions (12 for the X coordinate of a point, and 12 for the Y coordinate),
allowed one to convert between any combination of PAUs, MUs, fractional
coordinates, and user coordinates. PAUs and MUs are now obsolete; thus, only
four of the conversion functions are still pertinent: CFUX and CFUY allow
one to convert the X and Y coordinates of a point from the fractional system
to the user system, while CUFX and CUFY do the opposite.
To use one of these conversion routines, load the NCAR Graphics
libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order.
Online: cfux, cfuy, cmfx, cmfy, cmux, cmuy, cpfx, cpfy, cpux,
cpuy, cufx, cufy, kfmx, kfmy, kfpx, kfpy, kmpx, kmpy, kpmx, kpmy, kumx,
kumy, kupx, kupy, spps, ncarg_cbind
Hardcopy: NCAR Graphics Fundamentals, UNIX Version; User's Guide
for NCAR GKS-0A Graphics
Copyright (C) 1987-2009
University Corporation for Atmospheric Research
The use of this Software is governed by a License Agreement.