1 /*
2 *+
3 * Name:
4 * palDafin
5
6 * Purpose:
7 * Sexagesimal character string to angle
8
9 * Language:
10 * Starlink ANSI C
11
12 * Type of Module:
13 * Library routine
14
15 * Invocation:
16 * void palDafin ( const char *string, int *ipos, double *a, int *j );
17
18 * Arguments:
19 * string = const char * (Given)
20 * String containing deg, arcmin, arcsec fields
21 * ipos = int * (Given & Returned)
22 * Position to start decoding "string". First character
23 * is position 1 for compatibility with SLA. After
24 * calling this routine "iptr" will be positioned after
25 * the sexagesimal string.
26 * a = double * (Returned)
27 * Angle in radians.
28 * j = int * (Returned)
29 * status: 0 = OK
30 * +1 = default, A unchanged
31 * -1 = bad degrees )
32 * -2 = bad arcminutes ) (note 3)
33 * -3 = bad arcseconds )
34
35 * Description:
36 * Extracts an angle from a sexagesimal string with degrees, arcmin,
37 * arcsec fields using space or comma delimiters.
38
39 * Authors:
40 * TIMJ: Tim Jenness (JAC, Hawaii)
41 * PTW: Patrick T. Wallace
42 * {enter_new_authors_here}
43
44 * Example:
45 * argument before after
46 *
47 * STRING '-57 17 44.806 12 34 56.7' unchanged
48 * IPTR 1 16 (points to 12...)
49 * A ? -1.00000D0
50 * J ? 0
51
52 * Notes:
53 * - The first three "fields" in STRING are degrees, arcminutes,
54 * arcseconds, separated by spaces or commas. The degrees field
55 * may be signed, but not the others. The decoding is carried
56 * out by the palDfltin routine and is free-format.
57 * - Successive fields may be absent, defaulting to zero. For
58 * zero status, the only combinations allowed are degrees alone,
59 * degrees and arcminutes, and all three fields present. If all
60 * three fields are omitted, a status of +1 is returned and A is
61 * unchanged. In all other cases A is changed.
62 * - Range checking:
63 *
64 * The degrees field is not range checked. However, it is
65 * expected to be integral unless the other two fields are absent.
66 *
67 * The arcminutes field is expected to be 0-59, and integral if
68 * the arcseconds field is present. If the arcseconds field
69 * is absent, the arcminutes is expected to be 0-59.9999...
70 *
71 * The arcseconds field is expected to be 0-59.9999...
72 *
73 * - Decoding continues even when a check has failed. Under these
74 * circumstances the field takes the supplied value, defaulting
75 * to zero, and the result A is computed and returned.
76 * - Further fields after the three expected ones are not treated
77 * as an error. The pointer IPOS is left in the correct state
78 * for further decoding with the present routine or with palDfltin
79 * etc. See the example, above.
80 * - If STRING contains hours, minutes, seconds instead of degrees
81 * etc, or if the required units are turns (or days) instead of
82 * radians, the result A should be multiplied as follows:
83 *
84 * for to obtain multiply
85 * STRING A in A by
86 *
87 * d ' " radians 1 = 1.0
88 * d ' " turns 1/2pi = 0.1591549430918953358
89 * h m s radians 15 = 15.0
90 * h m s days 15/2pi = 2.3873241463784300365
91
92 * History:
93 * 2012-03-08 (TIMJ):
94 * Initial version from SLA/F using Fortran documentation
95 * Adapted with permission from the Fortran SLALIB library.
96 * 2012-10-17 (TIMJ):
97 * Fix range check on arcminute value.
98 * {enter_further_changes_here}
99
100 * Copyright:
101 * Copyright (C) 1996 Rutherford Appleton Laboratory
102 * Copyright (C) 2012 Science and Technology Facilities Council.
103 * All Rights Reserved.
104
105 * Licence:
106 * This program is free software; you can redistribute it and/or
107 * modify it under the terms of the GNU General Public License as
108 * published by the Free Software Foundation; either version 3 of
109 * the License, or (at your option) any later version.
110 *
111 * This program is distributed in the hope that it will be
112 * useful, but WITHOUT ANY WARRANTY; without even the implied
113 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
114 * PURPOSE. See the GNU General Public License for more details.
115 *
116 * You should have received a copy of the GNU General Public License
117 * along with this program; if not, write to the Free Software
118 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
119 * MA 02110-1301, USA.
120
121 * Bugs:
122 * {note_any_bugs_here}
123 *-
124 */
125
126 #include "pal.h"
127 #include "palmac.h"
128 #include "pal1sofa.h"
129
130 #include <math.h>
131
palDafin(const char * string,int * ipos,double * a,int * j)132 void palDafin ( const char *string, int *ipos, double *a, int *j ) {
133
134 int jd = 0; /* Status for degree parsing */
135 int jm = 0; /* Status for arcmin parsing */
136 int js = 0; /* Status for arcsec parsing */
137 int jf = 0; /* Internal copy of status */
138 double deg = 0.0;
139 double arcmin = 0.0;
140 double arcsec = 0.0;
141
142 /* Decode degrees, arcminutes, arcseconds */
143 palDfltin( string, ipos, °, &jd );
144 if (jd > 1) {
145 jf = -1;
146 } else {
147
148 palDfltin( string, ipos, &arcmin, &jm );
149 if ( jm < 0 || jm > 1 ) {
150 jf = -2;
151 } else {
152
153 palDfltin( string, ipos, &arcsec, &js );
154 if (js < 0 || js > 1) {
155 jf = -3;
156
157 } else if (jd > 0) { /* See if combination of fields is credible */
158 /* No degrees: arcmin, arcsec ought also to be absent */
159 if (jm == 0) {
160 /* Suspect arcmin */
161 jf = -2;
162 } else if (js == 0) {
163 /* Suspect arcsec */
164 jf = -3;
165 } else {
166 /* All three fields absent */
167 jf = 1;
168 }
169
170 } else if (jm != 0 && js == 0) { /* Deg present: if arcsec present should have arcmin */
171 jf = -3;
172
173 /* Tests for range and integrality */
174 } else if (jm == 0 && DINT(deg) != deg) { /* Degrees */
175 jf = -1;
176
177 } else if ( (js == 0 && DINT(arcmin) != arcmin) || arcmin >= 60.0 ) { /* Arcmin */
178 jf = -2;
179
180 } else if (arcsec >= 60.0) { /* Arcsec */
181 jf = -3;
182 }
183 }
184 }
185
186 /* Unless all three fields absent, compute angle value */
187 if (jf <= 0) {
188 *a = PAL__DAS2R * ( 60.0 * ( 60.0 * fabs(deg) + arcmin) + arcsec );
189 if ( jd < 0 ) *a *= -1.;
190 }
191
192 *j = jf;
193
194 }
195