1Areas_params(3NCARG) NCAR GRAPHICS Areas_params(3NCARG)
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6 Areas_params - This document briefly describes all Areas parameters.
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9 Areas currently supports nine parameters. These parameters are useful
10 mostly for debugging Areas problems. The current values may be
11 retrieved using one of the routines ARGETI or ARGETR. Parameter values
12 may be reset using the routine ARSETI or ARSETR; the parameter 'DI' is
13 for retrieval only and may not be given a new value by the user.
14 The Areas parameter descriptions appear below in alphabetical order.
16 Each description begins with a line giving the parameter name and the
17 intrinsic FORTRAN type of the parameter.
18 'AL' - Real
20 Arrowhead Length. AL specifies the length of each arrowhead
21 used on a debug plot produced by ARDBPA. The value is
22 interpreted as a fraction of the width of the plotter frame.
23 Using a value which is less than or equal to zero causes
24 arrowheads to be omitted. The default value is .008.
25 'AT' - Integer
27 Arithmetic Type flag. AT allows the user to specify the type of
28 arithmetic Areas is to use or to find out what type it decided
29 to use. A call to set the value of AT should precede any other
30 call to an Areas routine (except, possibly, one to set the value
31 of LC) and it should only be done once. A call to get the value
32 of AT will either return the value you set or a value picked by
33 Areas.
34 < 1 Areas decides what sort of arithmetic to use.
36 1 Real arithmetic is to be used.
38 2 Double-precision arithmetic is to be used.
40 3 Multiple-precision arithmetic is to be used and Areas is to
42 choose the base value.
43 > 3 Multiple-precision arithmetic is to be used and AT
45 specifies the base value. (For example, the value 100
46 specifies the use of base-100 multiple-precision integer
47 arithmetic.)
48 Default: 0
50 Note: You should use a nonzero value of AT only on the
52 recommendation of an NCAR consultant.
53 'AW' - Real
55 Arrowhead Width. AL specifies the half-width of each arrowhead
56 used on a debug plot produced by ARDBPA. The value is
57 interpreted as a fraction of the width of the plotter frame.
58 Using a value which is less than or equal to zero causes
59 arrowheads to be omitted. The default value is .002.
60 'DB' - Integer
62 DeBug-plots flag. DB allows the user to study the area map.
63 0 Debugging turned off. This is the default.
65 > 0 Debugging is on. At selected break points, ARPRAM produces
67 plots showing all edge segments in the area map that belong
68 to the edge group with group identifier DB.
69 'DC' - Integer
71 Debug Colors index. ARDBPA uses color indices DC+1 through DC+5
72 for debug-plot colors.
73 By default, DC=100, so ARDBPA defines and uses color indices 101
75 through 105.
76 'DI' - Integer
78 Direction Indicator flag. The value of DI is for retrieval only
79 and cannot be set by the user. A value returned for DI is
80 meaningful only when the call to ARGETI that retrieves it
81 originates from the user-written routine (dummy argument "APR")
82 that is called by ARSCAM. It then gives you information about
83 the area whose polygonal boundary is defined by the values of
84 APR's arguments. The two possible values of DI are:
85 1 Edge of the area is given in counterclockwise order (with
87 the interior to the left).
88 2 Edge of the area is given in clockwise order (with the
90 interior to the right).
91 'ID' - Real
94 Identifier Distance. ID specifies the distance from an arrow to
95 a left or right area identifier on a debug plot produced by
96 ARDBPA. The value is interpreted as a fraction of the width of
97 the plotter frame. Using a value which is less than or equal to
98 zero causes area identifiers to be omitted. The default value
99 is .004.
100 'IS' - Real
102 Identifier Size. IS specifies the size of the characters used
103 to write an area identifier on a debug plot produced by ARDBPA.
104 The value is interpreted as a fraction of the width of the
105 plotter frame. Using a value which is less than or equal to zero
106 causes area identifiers to be omitted. The default value is
107 .001.
108 'LC' - Integer
110 Largest Coordinate. LC lets you specify the largest coordinate
111 allowed in an area map. X and Y coordinates in an area map are
112 represented by integers in the range from 0 to LC, inclusive;
113 the default value of LC is 1000000.
114 The minimum value allowed for LC is 1000; attempting to set
116 LC<1000 gives it the value 1000. The value of LC must not be
117 greater than the largest integer on the machine on which Areas
118 is running; its value must also be exactly representable as a
119 real number on that machine.
120 A call to set the value of LC should precede any other call to
122 an Areas routine and should only be done once.
123 'RC' - Integer
125 Reconciling Conflicts in area-identifier information.
126 This is an array of 16 values, indexed by group identifier. To
128 set all values in the array to the same value "n", use "CALL
129 ARSETI('RC',n)"; to set just the first value in the array, use
130 "CALL ARSETI('RC(1)',n)"; to set just the second value, use
131 "CALL ARSETI('RC(2)',n)"; and so on. You can call ARGETI to get
132 the value of RC(1) or RC(2) or RC(3), etc.; if you ask for the
133 value of just RC, you will get the value of RC(1).
134 RC(1) is associated with edge group 1, RC(2) with edge group 2,
136 and so on. An edge group with a group identifier greater than
137 16 is associated with RC(16).
138 When the set of possible area identifiers for a given area in a
140 given group is contradictory, some algorithm must be used to
141 choose an identifier for the area. The value of that element of
142 RC that is associated with the group determines what algorithm
143 will be used, as follows:
144 0 The default scheme: If any of the possible area identifiers
146 is negative, use -1 as the identifier for the area.
147 Otherwise, if none of the possible values is non-zero, use
148 a zero identifier. Otherwise, from among the non-zero
149 possibilities, use the one most recently seen by AREAS.
150 1 The set of possible identifiers is examined: Zeroes are
152 ignored, negatives are treated as -1's, and the value that
153 occurs most frequently in the resulting set is used as the
154 identifier for the area.
155 2 Using RC = 2 is just like using RC = 1 except that zeroes
157 are not ignored: the area identifier used is simply the one
158 that occurs most frequently in the set of possibilities
159 (all negatives being treated as -1's).
160 -1 Using RC = -1 is just like using RC = 1 except that, if
162 there are any negatives in the set of possible identifiers,
163 a -1 is used.
164 -2 Using RC = -2 is just like using RC = 2 except that, if
166 there are any negatives in the set of possible identifiers,
167 a -1 is used.
168
170 Online: argeti, argetr, arseti, arsetr
171 Hardcopy: NCAR Graphics Contouring and Mapping Tutorial
173
175 Copyright (C) 1987-2009
176 University Corporation for Atmospheric Research
177 The use of this Software is governed by a License Agreement.
178UNIX April 1995 Areas_params(3NCARG)