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

6       Dashpack_params - This document briefly describes all Dashpack
7       parameters.
8

DESCRIPTION

10       Dashpack has twenty internal parameters that affect what it does.  The
11       current value of a parameter may be retrieved by calling one of the
12       routines DPGETC, DPGETI or DPGETR.  A parameter may be given a new
13       value by calling one of the routines DPSETC, DPSETI, or DPSETR.
14
15       The Dashpack 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
19       'CRB' - Character
20
21              Character Representing a Break: the single character that is to
22              be used in a label string in a character dash pattern to
23              represent a break point in the label string. (Each piece of the
24              label string is written using a separate call to PLCHHQ, PLCHMQ,
25              or PLCHLQ; the effect is to make the label "bend" with the curve
26              that it labels.)
27
28              The default value of 'CRB' is a vertical bar.
29
30       'CRG' - Character
31
32              Character Representing a Gap: the single character that is to be
33              used in a character dash pattern to represent a gap (of width
34              'WOG') in the curve.
35
36              The default value of 'CRG' is an underscore.
37
38       'CRS' - Character
39
40              Character Representing a Solid: the single character that is to
41              be used in a character dash pattern to represent a solid section
42              (of width 'WOS') of the curve.
43
44              The default value of 'CRS' is a dollar sign.
45
46       'DPL' - Integer
47
48              Dash Pattern Length: the length of the character-string value of
49              the internal parameter 'DPT', as set by DPSETC or by a
50              subsequent call to DPSETI or DPSETR.  Calling DPSETC with first
51              argument 'DPT' sets both 'DPT', which is the character dash
52              pattern, and 'DPL', which is its length; 'DPL' can later be
53              reset (normally to a smaller value) by a subsequent call to
54              DPSETI or DPSETR with first argument 'DPL', thus requesting the
55              use of a different number of characters of the specified dash
56              pattern.
57
58              The value of 'DPL' must be between 1 and 256.
59
60              The default value is 16.
61
62       'DPS' - Integer
63
64              Dash Pattern Selector: selects the dash pattern to be used.
65
66              A negative value of 'DPS' says that the integer dash pattern (as
67              specified by a call to DPSETI or DPSETR with first argument
68              'DPT') is to be used.  If the absolute value is "n", then the
69              low-order "n" bits of the integer are used as the dash pattern.
70              No more than 32 bits of an integer dash pattern may be used;
71              using more than 24 may be a problem on some systems.
72
73              A positive value of 'DPS' says that the current character dash
74              pattern (as specified by a call to DPSETC with first argument
75              'DPT') is to be used; 'DPS' = 0 says to use the first 'DPL'
76              characters of the dash pattern, while 'DPS' > 0 says to use the
77              first 'DPS' characters of the dash pattern.  No more than 256
78              characters of a character dash pattern may be used.
79
80              The value of 'DPS' must be between -32 and +256.
81
82              The default value is 0.
83
84       'DPT' - Character or Integer
85
86              Dash PaTtern: one of the current dash patterns. (In a call to
87              DPSETC or DPGETC, the name 'DPT' refers to the current
88              character-string dash pattern, but in a call to DPSETI, DPGETI,
89              DPSETR, or DPGETR, it refers to the current integer dash
90              pattern.  Which of these is actually in use at a given time is
91              specified by the value of the internal parameter 'DPS'.)
92
93              In an integer dash pattern, 1 bits represent solids and 0 bits
94              represent gaps.  No more than 32 bits of an integer dash pattern
95              may be used; using more than 24 bits may be a problem on some
96              systems.
97
98              A character dash pattern is a string of 256 or fewer characters;
99              in such a string, occurrences of the characters specified by the
100              values of 'CRG' and 'CRS' specify gaps and solids, respectively.
101              Other characters in the dash pattern form label strings to be
102              written along a curve.  Within each complete label string of a
103              character dash pattern, the character specified by the value of
104              'CRB' may be used to specify "break points" at which the label
105              string may be broken into smaller substrings. Alternatively, the
106              single-character flag 'SCF' may be set non-zero to say that the
107              label string may be broken into single-character substrings.
108              Since each such substring is written by a separate call to
109              PLCHHQ, PLCHMQ, or PLCHLQ, the effect of breaking up a label
110              string is to make the label "bend" with the curve.
111
112              The default character dash pattern consists of sixteen dollar
113              signs, and the default integer dash pattern is "65535", which
114              has sixteen low-order 1s.
115
116       'EPS' - Real
117
118              EPSilon: says how far apart two points have to be (in X or Y, in
119              the fractional coordinate system) in order to be considered
120              separate points by the smoothing routine DPSMTH.
121
122              The value of 'EPS' must be greater than or equal to zero.
123
124              The default value is .000001.
125
126       'LS1' - Real
127
128              Label Spacing parameter 1: specifies how much extra gap space to
129              leave at the beginning and end of a label. Giving 'LS1' a non-
130              zero value helps to ensure that there will be a sufficiently
131              large gap to (for example) prevent a leading minus sign from
132              appearing to be part of the line.
133
134              The value of 'LS1' is given as a multiple of the value of the
135              parameter 'WOC' (the width of a character); it must not be less
136              than zero nor greater than 10.
137
138              The default value is .5.
139
140       'LS2' - Real
141
142              Label Spacing parameter 2: specifies how much extra gap space to
143              leave for each piece of a broken label. When break characters
144              are used or the single-character flag 'SCF' is turned on, 'LS2'
145              determines the spacing of the characters along the line.
146
147              The value of 'LS2' is given as a multiple of the value of the
148              parameter 'WOC' (the width of a character); it must not be less
149              than zero nor greater than 10.
150
151              The default value is 0.
152
153       'LTL' - Integer
154
155              Line Through Label: a flag that says whether or not each label
156              substring specified by a character dash pattern is to be written
157              in a gap ('LTL' = 0) or just on top of the curve ('LTL' = 1).
158              The latter is most effective if the line is one color and the
159              labels are another color.
160
161              The value of 'LTL' must be either 0 or 1.
162
163              The default value is 0.
164
165       'MFS' - Real
166
167              Multiplier for First Solid: a real multiplier for the length of
168              an initial solid portion of a curve drawn by DASHPACK. The
169              object of using this is to make it possible to slightly offset
170              labels on curves that are very nearly parallel to one another
171              (as can happen, for example, when drawing contour lines).
172
173              The value of 'MFS' must be greater than or equal to zero.
174
175              The default value is 1.
176
177       'PCF' - Integer
178
179              PlotChar Flag: says which PLOTCHAR routine is to be called to
180              draw character strings. The value 0 says to call PLCHHQ, the
181              value 1 says to call PLCHMQ, and the value 2 says to call
182              PLCHLQ.
183
184              The value of 'PCF" must be either 0, 1, or 2.
185
186              The default value is 0.
187
188       'SAF' - Real
189
190              String Angle Flag: says how labels are to be oriented.
191
192              If 'SAF' = 0, labels are written along a curve in the direction
193              in which the curve is being drawn.
194
195              If 'SAF' is negative, labels are written in the direction
196              ABS('SAF') degrees, but this is done only if 'LTL' is non-zero;
197              otherwise, the code behaves as if 'SAF' were zero: labels are
198              written in the direction of the curve.
199
200              If 'SAF' is greater than zero, labels are written along the
201              curve, but the angle is adjusted by adding multiples of 180
202              degrees so that the resulting angle lies in the range from
203              'SAF'-90 to 'SAF'+90 degrees.
204
205              If a label string is broken into substrings (either because
206              there are "break" characters in it or because 'SCF' is non-
207              zero), a negative value of 'SAF' will be treated as a zero
208              value; a value greater than zero may cause the entire label to
209              be written in the opposite direction along the curve if that
210              ensures that more characters of the label will be written at
211              angles between 'SAF'-90 and 'SAF'+90 degrees.
212
213              Generally, when 'SAF' is non-zero, it is either -360 or +360,
214              which has the effect of making the labels as nearly upright as
215              possible on the frame.
216
217              The value of 'SAF" must be in the range from -360 to +360.
218
219              The default value is 360.
220
221       'SBF' - Integer
222
223              String Buffering Flag: a flag that says whether output of labels
224              is to be buffered or not.
225
226              When 'SBF' is non-zero, buffering is done.  This ensures that,
227              if the end of a curve occurs anywhere within a particular label,
228              no part of the label is written; instead, that part of the curve
229              is drawn using only the gap and solid elements of the dash
230              pattern.  Buffering is also important when 'SCF' is non-zero or
231              there are "break" characters in a label string and 'SAF' is
232              greater than zero; in this case, the buffering makes it possible
233              to reorient the label as needed to make most of it upright.
234
235              When 'SBF' is zero, buffering is turned off. There may be gaps
236              at the ends of curves.  If, in addition, 'SCF' is non-zero or
237              there are "break" characters in label strings, there may be
238              partial labels at the ends of curves.
239
240              The value of 'SBF' must be either 0 or 1.
241
242              The default value is 1.
243
244       'SCF' - Integer
245
246              Single Character Flag: When 'SCF' is non-zero, it says that the
247              label-string portions of character dash patterns are to be
248              broken into single-character pieces, each of which is to be
249              written by a separate call to PLCHHQ, PLCHMQ, or PLCHLQ.
250
251              If 'SCF' = 0, label strings are broken into pieces only at the
252              break points indicated by the use of "break" characters in the
253              strings.
254
255              It is not appropriate to use 'SCF' non-zero when PLCHHQ is being
256              used and a label string in the dash pattern contains function
257              codes that are meaningful to PLCHHQ; in that case, one should
258              leave 'SCF' = 0 and use the "break" character 'CRB' in the label
259              string to tell DASHPACK where it can be broken.
260
261              The value of 'SCF" must be either 0 or 1.
262
263              The default value is 0.
264
265       'SSL' - Real
266
267              Smoothed Segment Length: specifies how far apart the points used
268              to draw a smoothed curve should be.
269
270              The value of 'SSL' is given in the fractional coordinate system
271              and must be in the range from .000001 to 1.
272
273              The default value is .01.
274
275       'TCS' - Real
276
277              Tension on Cubic Splines: a value which, if negative, turns
278              smoothing off, and which, if non-negative, turns smoothing on
279              and, if greater than zero, specifies the desired tension to be
280              used on the cubic splines used to do the smoothing.
281
282              Note that only the routines DPCURV, DPFRST, DPVECT, DPLAST, and
283              DPSMTH are affected by the value of 'TCS'; the routines DPLINE
284              and DPDRAW never smooth. The routine DPSMTH always smooths: if
285              'TCS' is less than or equal to zero, simple cubic splines are
286              used, and, if 'TCS' is greater than zero, splines under tension
287              are used, in which case 'TCS' specifies the desired tension.
288
289              It's a bad idea to use values of 'TCS' much bigger than about
290              15, as this can cause overflows in the smoothing routines.
291
292              The default value is -1.
293
294       'WOC' - Real
295
296              Width Of Character: the character width to be used in writing
297              labels.
298
299              The value of 'WOC' is given in the fractional coordinate system
300              and must be in the range from .000001 to 1.
301
302              The default value is .01.
303
304       'WOG' - Real
305
306              Width of Gap: the width of each gap in the dashed line.
307
308              The value of 'WOG' is given in the fractional coordinate system
309              and must be in the range from .000001 to 1.
310
311              The default value is .005.
312
313       'WOS' - Real
314
315              Width of Solid: the width of each solid in the dashed line.
316
317              The value of 'WOS' is given in the fractional coordinate system
318              and must be in the range from .000001 to 1.
319
320              The default value is .005.
321

SEE ALSO

323       Online: dashpack, dpcurv, dpdraw, dpfrst, dpgetc, dpgeti, dpgetr,
324       dplast, dpline, dpsetc, dpseti, dpsetr, dpsmth, dpvect,
325
326       Hardcopy: None.
327
329       Copyright (C) 1987-2009
330       University Corporation for Atmospheric Research
331       The use of this Software is governed by a License Agreement.
332
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335UNIX                              March 1995           Dashpack_params(3NCARG)
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