1Dashline_params(3NCARG)          NCAR GRAPHICS         Dashline_params(3NCARG)
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NAME

6       Dashline_params - Brief descriptions of all internal parameters of
7       Dashline.
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DESCRIPTION

10       No parameter-access routines are available for the utility Dashline.
11       Parameters are set through the common blocks SMFLAG, INTPR, and DASHD1.
12
13       There are four different versions of Dashline: normal, quick, smooth,
14       and super.  Which version is used depends on options used on the
15       ncargf77 command line.  The lines drawn by the different versions can
16       vary considerably in appearance.
17
18       The following set of common blocks may be used to access any of the
19       internal parameters of the Dashline utility:
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21
22          COMMON /SMFLAG/ IOFFS
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24          COMMON /INTPR / IPAU,FPART,TENSN,NP,SMALL,L1,ADDLR,ADDTB,MLLINE,
25         +                ICLOSE
26
27          COMMON /DASHD1/ ISL,L,ISIZE,IP(100),NWDSM1,IPFLAG(100),MNCSTR,IGP
28
29       The following table indicates which of the internal parameters affect
30       the behavior of the various versions of Dashline ("Y" indicates an
31       effect, "N" indicates no effect):
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35         Parameter   QUICK   NORMAL   SMOOTH   SUPER
36         ---------   -----   ------   ------   -----
37         ADDLR         N       N        N        Y
38         ADDTB         N       N        N        Y
39         FPART         N       Y        Y        Y
40         ICLOSE        Y       Y        Y        Y
41         IGP           N       Y        Y        Y
42         IOFFS         N       N        Y        Y
43         IPAU          Y       Y        Y        Y
44         L1            N       N        Y        Y
45         MLLINE        N       N        N        Y
46         NP            N       N        Y        Y
47         SMALL         N       N        Y        Y
48         TENSN         N       N        Y        Y
49
50       PARAMETER DESCRIPTIONS
51
52       ADDLR       The amount of free space to be left on the left and on the
53                   right of each character string, stated as the desired
54                   number of NDCs (Normalized Device Coordinates) times 1023.
55                   This only affects the "super" version of Dashline; it
56                   changes the size of the area marked around a label in the
57                   bit map that is used for culling crowded lines.  [Default =
58                   2. (2./1023. NDCs)]
59
60       ADDTB       The amount of free space to be left on the top and on the
61                   bottom of each character string, stated as the desired
62                   number of NDCs (Normalized Device Coordinates) times 1023.
63                   This only affects the "super" version of Dashline; it
64                   changes the size of the area marked around a label in the
65                   bit map that is used for culling crowded lines.  [Default =
66                   2. (2./1023. NDCs)]
67
68       FPART       A multiplication factor for the length of the first solid
69                   line segment on any curve.  This can be used to offset
70                   labels.  For example, if FPART = .5, the first solid line
71                   segment is only one-half as long as the other solid line
72                   segments.  This will move all labels on the current curve
73                   towards the beginning of the curve and thereby reduce the
74                   probability of a label being written on top of a label on a
75                   nearby curve drawn with FPART = 1.  [Default = 1.]
76
77       ICLOSE      An internal or external call to move the "drawing pen"
78                   (pen-up) to a specific position is executed only if the
79                   position is more than ICLOSE units away from the current
80                   pen position (the distance is measured as the absolute
81                   difference in X-coordinates plus the absolute difference in
82                   Y-coordinates).  The unit of measurement is 32767 integer
83                   units in each of the X and Y dimensions.  [Default = 6]
84
85       IGP         Flag to control whether gaps are left for labels along a
86                   curve.  If no gaps are left, the labels don't look as good,
87                   but you can be sure of what the curve is doing in the
88                   regions occupied by the labels.
89
90                   9  A gap is left.
91
92                   0  No gap is left.
93
94                   [Default = 9]
95
96       IOFFS       Flag used to turn smoothing off.
97
98                   0  Smoothing.
99
100                   1  No smoothing.
101
102                   [Default = 0]
103
104       IPAU        The length of the gap or solid line associated with each
105                   element of a dash pattern defined by a call to DASHDB,
106                   given as the desired value in NDCs (Normalized Device
107                   Coordinates) times 1023.  Such a dash pattern is repeated
108                   approximately every REAL(IPAU)/64. NDC units along the
109                   length of a curve.  [Default = 3 (3./1023. NDCs)]
110
111       L1          The maximum number of points to be saved at one time.  If
112                   there are more than L1 points on a given line, L1 points
113                   are processed, then the next L1, and so on, until the
114                   entire line is processed.  Smoothness between segments is
115                   maintained automatically.  If L1 is increased, the
116                   dimensions of XSAVE, YSAVE, XP, YP, TEMP, and SLEN in the
117                   routine FDVDLD must be increased to the new value of L1.
118                   [Default = 70]
119
120       MLLINE      The maximum length in either coordinate of a single line
121                   segment to be processed by the crowded line algorithm.
122                   Line segments longer than MLLINE units in either coordinate
123                   are broken into smaller segments, each of which is
124                   processed separately.  This is done to prevent anomalies in
125                   the removal of long line segments, since only the starting
126                   point and end point of each line segment is checked in that
127                   process.  The unit of measurement is 32767 integer units in
128                   each of the X and Y dimensions.  [Default = 384]
129
130       NP          Determines how many points are used to draw each smoothed
131                   curve.  The value of NP is twice the maximum number of
132                   interpolated points on a horizontal curve with length equal
133                   to that of the width of the grid.  More points per unit
134                   length are interpolated for short lines than for long
135                   lines.  [Default = 150]
136
137       SMALL       When the points on a line are being processed, only the
138                   first of two consecutive points is saved if the points are
139                   less than SMALL units apart.  This procedure is to prevent
140                   cusps.  The unit of measurement is 32767 integer units in
141                   each of the X and Y dimensions.  [Default = 128.]
142
143       TENSN       Tension factor.  Must be greater than 0.  A large tension
144                   factor (30.) would essentially turn off smoothing.
145                   [Default = 2.5]
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SEE ALSO

148       Online: dashline, curved, dashdb, dashdc, frstd, lastd, lined, reset,
149       vectd, ncarg_cbind
150
151       Hardcopy: NCAR Graphics Contouring and Mapping Tutorial; NCAR Graphics
152       Fundamentals, UNIX Version; User's Guide for NCAR GKS-0A Graphics
153
155       Copyright (C) 1987-2009
156       University Corporation for Atmospheric Research
157       The use of this Software is governed by a License Agreement.
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161UNIX                              March 1993           Dashline_params(3NCARG)
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