1CUFY(3NCARG) NCAR GRAPHICS CUFY(3NCARG)
2
6 CUFY - Converts from user coordinates to fractional coordinates.
7SPPS_converters(3NCARG) NCAR GRAPHICS SPPS_converters(3NCARG)
11
15 spps_converters - A set of functions, each of which transforms a
16 coordinate from one of the NCAR Graphics coordinate systems to another.
17 The complete list of functions is as follows: CFUX, CFUY, CMFX, CMFY,
18 CMUX, CMUY, CPFX, CPFY, CPUX, CPUY, CUFX, CUFY, KFMX, KFMY, KFPX, KFPY,
19 KMPX, KMPY, KPMX, KPMY, KUMX, KUMY, KUPX, and KUPY.
20
22 Plotter Address Units (PAUs) and Metacode Units (MUs) are no longer
23 used in NCAR Graphics; thus, all functions with either an M or a P as
24 the second or third letter of the function name are considered
25 obsolete.
26 The current recognized coordinate systems are GKS world coordinates,
28 GKS normalized device coordinates, NCAR Graphics fractional
29 coordinates, and NCAR Graphics user coordinates. See the NCAR Graphics
30 document "NCAR Graphics Fundamentals, UNIX Version" for descriptions of
31 these coordinate systems.
32 The following definitions of the PAU coordinate system and the MU
34 coordinate system are provided for the purpose of interpreting and
35 converting codes which use PAUs or MUs:
36 The plotter coordinates of a point are integers IPX and IPY, where IPX
38 is between 1 and 2**MX and IPY is between 1 and 2**MY. MX and MY are
39 internal parameters of SPPS; each has a default value of 10. Values of
40 MX and MY can be set by calling the routines SETI or SETUSV and
41 retrieved by calling the routines GETSI or GETUSV.
42 The metacode coordinates of a point are integers IMX and IMY between 0
44 and 32767 inclusive. The area addressed is a square in a "metacode
45 space" that is usually mapped into a square subset of the addressable
46 area of the plotting device. Metacode coordinates were used in calls
47 to the routine PLOTIT and are returned in calls to FL2INT.
48
50 Current:
51 X = CFUX (RX), Y = CFUY(RY)
52 X = CUFX (RX), Y = CUFY(RY)
53 Obsolete:
55 X = CMUX (IX), Y = CMUY(IY)
56 X = CPUX (IX), Y = CPUY(IY)
57 X = CMFX (IX), Y = CMFY(IY)
58 X = CPFX (IX), Y = CPFY(IY)
59 I = KFMX (RX), J = KFMY(RY)
60 I = KUMX (RX), J = KUMY(RY)
61 I = KFPX (RX), J = KFPY(RY)
62 I = KUPX (RX), J = KUPY(RY)
63 I = KPMX (IX), J = KPMY(IY)
64 I = KMPX (IX), J = KMPY(IY)
65
67 #include <ncarg/ncargC.h>
68 float c_cfux (float rx)
70 float c_cfuy (float ry)
72 float c_cufx (float rx)
74 float c_cufy (float ry)
76
78 RX (an input expression of type REAL) is an X coordinate in
79 the coordinate system specified by the second letter of the
80 function name. In a reference to CFUX, RX is a fractional
81 X coordinate; in a reference to CUFX, RX is a user X
82 coordinate.
83 RY (an input expression of type REAL) is a Y coordinate in the
85 coordinate system specified by the second letter of the
86 function name. In a reference to CFUY, RY is a fractional
87 Y coordinate; in a reference to CUFY, RY is a user Y
88 coordinate.
89 IX and IY occur as arguments only in references to some of the obsolete
91 functions; they represent input expressions of type INTEGER, specifying
92 the X and Y coordinates of a point in either PAUs or MUs (depending on
93 the second letter of the function name).
94 The first letter of the function name is a C if the result is of type
96 REAL and a K if the result is of type INTEGER (the latter only happens
97 for some of the obsolete ones). This conforms to the usual FORTRAN
98 convention for implicit typing.
99 The second letter of the function name specifies the coordinate system
101 of the argument.
102 The third letter of the function name specifies the coordinate system
104 of the functional result. In references to CFUX and CFUY, the result
105 is in the user system; in references to CUFX and CUFY, the result is in
106 the fractional system.
107 The fourth letter of the function name is an X or a Y, depending on
109 whether an X or a Y coordinate is being converted.
110
112 The C-binding argument description is the same as the FORTRAN argument
113 description.
114
116 Use the ncargex command to see the following relevant examples which
117 use coordinate converters: mpex10, cbex10, sfex02, epltch.
118 The command "ncargex -n mpex10" will load the driver mpex10.f into your
120 current working directory where you can examine the file using a local
121 editor, or the UNIX more command.
122
124 There were 24 conversion functions in the original set. These
125 functions (12 for the X coordinate of a point, and 12 for the Y
126 coordinate), allowed one to convert between any combination of PAUs,
127 MUs, fractional coordinates, and user coordinates. PAUs and MUs are
128 now obsolete; thus, only four of the conversion functions are still
129 pertinent: CFUX and CFUY allow one to convert the X and Y coordinates
130 of a point from the fractional system to the user system, while CUFX
131 and CUFY do the opposite.
132 To use any of the conversion routines, load the load the NCAR Graphics
134 libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order.
135
137 Online: cfux, cfuy, cmfx, cmfy, cmux, cmuy, cpfx, cpfy, cpux, cpuy,
138 cufx, cufy, kfmx, kfmy, kfpx, kfpy, kmpx, kmpy, kpmx, kpmy, kumx, kumy,
139 kupx, kupy, spps, ncarg_cbind
140 Hardcopy: NCAR Graphics Fundamentals, UNIX Version; User's Guide for
142 NCAR GKS-0A Graphics
143
145 Copyright (C) 1987-2009
146 University Corporation for Atmospheric Research
147 The use of this Software is governed by a License Agreement.
149UNIX March 1993 SPPS_converters(3NCARG)