1CPCNRC(3NCARG) NCAR GRAPHICS CPCNRC(3NCARG)
2
6 CPCNRC - Draws black and white contours with a single call. the
7 behavior of the old routine CONREC; it has the same arguments and
8 produces similar output.
9
11 CALL CPCNRC (ZDAT, KZDT, MZDT, NZDT, FLOW, FHGH, FINC,
12 + NSET, NHGH, NDSH)
13
15 #include <ncarg/ncargC.h>
16 void c_cpcnrc (float *zdat, int kzdt, int mzdt, int nzdt,
18 float flow, float fhgh, float finc, int nset, int nhgh,
19 int ndsh)
20
22 ZDAT (REAL array, dimensioned KZDT x n, where "n" is greater
23 than or equal to NZDT, input) is the array containing the
24 data to be contoured.
25 KZDT (INTEGER, input) is the first dimension of the FORTRAN
27 array ZDAT.
28 MZDT (INTEGER, input) is the first dimension of the array of
30 data in ZDAT. MZDT must be less than or equal to KZDT.
31 NZDT (INTEGER, input) is the second dimension of the array of
33 data in ZDAT. NZDT must be less than or equal to the
34 declared second dimension of the array ZDAT.
35 FLOW (REAL, input) is the desired lowest contour level. If FLOW
37 is equal to or greater than FHGH, Conpack will choose the
38 set of contour levels.
39 FHGH (REAL, input) is the desired highest contour level. If FHGH
41 is equal to or less than FLOW, Conpack will choose the set
42 of contour levels.
43 FINC (REAL, input) says how contour levels are to be chosen.
45 There are two possibilities:
46 · If FINC is greater than zero, it specifies the desired
48 contour interval to be used. In this case, if FLOW is
49 less than FHGH, the intervals used will be FLOW,
50 FLOW+FINC, FLOW+2*FINC, ... FLOW+n*FINC, where "n" is
51 the largest integer such that FLOW+n*FINC is less than
52 or equal to FHGH. If FLOW is greater than or equal to
53 FHGH, the contour levels will be those integer
54 multiples of FINC which fall between the minimum value
55 in ZDAT and the maximum value in ZDAT.
56 · If FINC is less than or equal to zero, Conpack will
58 choose the contour interval in such a way as to give at
59 least 16 contour levels (if FINC is zero) or
60 MAX(1,INT(-FINC)) contour levels (if FINC is less than
61 zero) between the minimum and maximum values in ZDAT.
62 All the contour levels will be integer multiples of the
63 chosen interval. If FLOW is less than FHGH, no contour
64 lines will be drawn for chosen contour levels which are
65 outside the range (FLOW,FHGH).
66 NSET (INTEGER, input) says how the contour plot is to be mapped
68 onto the plotter frame. There are three basic
69 possibilities:
70 · If the value of NSET, modulo three, is zero, the
72 "standard configuration" will be used. Conpack will be
73 directed to call SET. The portion of the plotter frame
74 bounded by the lines "X=.05", "X=.95", "Y=.05", and
75 "Y=.95" (in the "fractional" or "normalized-device-
76 coordinate" system) will be used. The shape of the plot
77 will be determined by the values of the internal
78 parameters 'WDL', 'WDR', 'WDB', and 'WDT'; by default,
79 the ratio of the plot's width to its height will be
80 MZDT/NZDT. If the ratio of the width to the height is
81 less than 1/4 or greater than 4, the plot will be made
82 square. CPBACK will be called to draw a perimeter.
83 · If the value of NSET, modulo three, is equivalent to
85 minus one, the contour plot will fill the current
86 viewport. Conpack will be directed to call SET. The
87 portion of the plotter frame used will be that bounded
88 by the lines "X=xl", "X=xr", "Y=yb", and "Y=yt", where
89 "xl", "xr", "yl", and "yr" are obtained by means of a
90 CALL GETSET (xl,xr,yl,yr,...)
92 The plot will fill this entire area. CPBACK will not be
94 called to draw a perimeter.
95 · If the value of NSET, modulo three, is equivalent to
97 plus one, Conpack will be directed not to call SET. It
98 will be assumed that the user has done the appropriate
99 call. CPBACK will not be called to draw a perimeter.
100 Use this option when overlaying CPCNRC output on an
101 existing background (one drawn by Ezmap, for example).
102 If the value of NSET is -1, 0, or 1, CPCNRC will, prior to
104 returning control to the caller, restore the SET call to
105 what it was on entry (which is how CONREC works). If the
106 value of NSET is less than -1 or greater than 1, CPCNRC
107 will not so restore the SET call; this may be useful if
108 other objects are to be drawn on the plot produced by
109 CPCNRC.
110 NHGH (INTEGER, input) says whether highs and lows or data points
112 are to be labeled. There are three possibilities:
113 · If NHGH is zero, each high is marked with an "H" and
115 each low is marked with an "L"; the value is written as
116 a subscript of the "H" or "L".
117 · If NHGH is greater than zero, each data point is marked
119 with the value at that point. No attempt is made to
120 cull overlapping values, so using this option when
121 there are too many data points may result in a mess.
122 The values of the Conpack parameters 'HLA' and 'HLS'
123 are retrieved and used to determine the angle at which
124 the values are written and the size of the characters
125 used. They may be used to reduce the clutter somewhat.
126 · If NHGH is less than zero, neither of the above is
128 done.
129 NDSH (INTEGER, input) may be used to specify a 10-bit dash
131 pattern to be used. (If ABS(NDSH) is 0, 1, or 1023, all
132 solid lines are used.) If NDSH is greater than zero, the
133 specified dash pattern is used for all contour lines; if
134 NDSH is less than zero, the dash pattern is used only for
135 negative-valued contour lines. Note: the 10-bit pattern is
136 actually made into a 16-bit pattern by appending a copy of
137 the high-order six bits.
138
140 The C-binding argument descriptions are the same as the FORTRAN
141 argument descriptions with the following exceptions:
142 zdat Dimensioned n by kzdt, where n is greater than or equal to
145 nzdt.
146 kzdt The second dimension of the array zdat.
148 mzdt The second dimension of the array of data in zdat. mzdt
150 must be less than or equal to kzdt.
151 nzdt The first dimension of the array of data in zdat. nzdt must
153 be less than or equal to the declared first dimension of
154 the array zdat.
155
157 The appearance of the plot produced by CPCNRC may vary, depending on
158 the setting of internal parameters of Conpack. The following should be
159 noted:
160 · By default, contour lines will be labeled using the old CONREC
162 scheme of appending the label for a line to the dash pattern for
163 the line. To use one of the new schemes, place a
164 CALL CPSETI ('LLP - LINE LABEL POSITIONING',n)
166 where n has the value 2 or 3, before the call to CPCNRC. CPCNRC
168 retrieves the value of 'LLP' and, if the value is a 2 or a 3,
169 modifies the calls that it performs so as to properly shield labels
170 from having contour lines drawn through them.
171 · By default, high-quality characters will be used in the
173 informational label, in high/low labels, in point-value labels, and
174 in contour-line labels written when 'LLP' is 2 or 3. To use lower-
175 quality characters, place a
176 CALL PCSETI ('QUALITY',1)
178 or a
180 CALL PCSETI ('QUALITY',2)
182 prior to the call to CPCNRC.
184 Note that these calls are to subroutines that start with the
186 letters PC, because the routine you are calling is in the utility
187 Plotchar. (Conpack uses Plotchar to plot characters.)
188 · If the output from CPCNRC is to be overlaid on an Ezmap background
190 and longitude is a linear function of the first subscript of the
191 data array and latitude is a linear function of the second
192 subscript of the data array, you can
193 Call Ezmap to draw the background.
195 Set the parameter 'MAP' to 1.
197 Set the parameters 'XC1', 'XCM', 'YC1', and 'YCN' to specify
199 the longitude and latitude ranges. Note: 'XCM' must be
200 numerically larger than 'XC1'. If, for example, your data
201 run from 175 degrees east of Greenwich at the left edge to
202 160 degrees west of Greenwich at the right edge (which is
203 -160 degrees east), then you should set 'XC1' = 175 and 'XCM'
204 = 200 to achieve the proper mapping.
205 Call CPCNRC to draw the contour plot.
207 · To smooth the contour lines in the same way that they would have
209 been smoothed by the "smooth" or "super" versions of CONREC, insert
210 CALL CPSETR ('T2D - TENSION ON THE 2D SPLINES',t),
212 where t is the desired tension, to turn on the smoother.
214 · By default, no scale factor is used. (Because Conpack can write
216 contour line labels in scientific notation, it was considered less
217 important to use a scale factor.) If you want to use a scale
218 factor, the value of the internal parameter 'SFS' should be set
219 prior to calling CPCNRC.
220 · CPCNRC contains a real workspace array, an integer workspace array,
222 and an area map, which is used to prevent contour lines from
223 passing through labels when 'LLP' has the value 2 or 3. The lengths
224 of these arrays are 5000, 2000, and 12000, respectively. If this
225 proves insufficient, you must obtain a copy of the code for CPCNRC,
226 adjust the dimensions as required, and compile it in place of the
227 default version.
228 · Certain internal parameters are used by CPCNRC; user calls to reset
230 them prior to the call to CPCNRC will therefore have no effect.
231 These parameters are as follows:
232 'AIA' 'AIB' 'CIS' 'CIU' 'CLC' 'CLD' 'CLL' 'CLS' 'CLV' 'CLU' 'CMN'
234 'CMX' 'HLT' 'HIT' 'LOT' 'LLC' 'LLT' 'NCL' 'SET' 'VPB' 'VPL' 'VPR'
235 'VPS' 'VPT'
236 · Subroutines with names of the form CPCHxx (the change subroutines)
238 will be of more value when used in conjunction with CPCNRC than
239 when used in conjunction with the more basic Conpack subroutines.
240 For example, the only way to change the color of the zero contour
241 line drawn by a call to CPCNRC is to supply your own version of the
242 routine CPCHCL; there is no way, short of modifying the code of
243 CPCNRC, to use the internal parameter that controls the color of
244 the zero contour line.
245 · Like CONREC, CPCNRC does no call to FRAME. To advance the frame,
247 put a CALL FRAME after the call to CPCNRC.
248
250 Use the ncargex command to see the following relevant examples:
251 ccpcnrc, cpex09, tconpa.
252
254 To use CPCNRC or c_cpcnrc, load the NCAR Graphics libraries ncarg,
255 ncarg_gks, and ncarg_c, preferably in that order.
256
258 Online: conpack, cpback, cpchcf, cpchcl, cpchhl, cpchil, cpchll,
259 cpcica, cpclam, cpcldm, cpcldr, cpcltr, cpdrpl, cpezct, cpgetc, cpgeti,
260 cpgetr, cplbam, cplbdr, cpmpxy, cpmviw, cpmvrw, cppkcl, cppklb, cprect,
261 cprset, cpscae, cpsetc, cpseti, cpsetr, cpsps1, cpsps2, ncarg_cbind
262 Hardcopy: NCAR Graphics Contouring and Mapping Tutorial
264
266 Copyright (C) 1987-2009
267 University Corporation for Atmospheric Research
268 The use of this Software is governed by a License Agreement.
270UNIX March 1993 CPCNRC(3NCARG)