GeographicLib  2.1.2
DMS.hpp
Go to the documentation of this file.
1 /**
2  * \file DMS.hpp
3  * \brief Header for GeographicLib::DMS class
4  *
5  * Copyright (c) Charles Karney (2008-2022) <charles@karney.com> and licensed
6  * under the MIT/X11 License. For more information, see
7  * https://geographiclib.sourceforge.io/
8  **********************************************************************/
9 
10 #if !defined(GEOGRAPHICLIB_DMS_HPP)
11 #define GEOGRAPHICLIB_DMS_HPP 1
12 
15 
16 #if defined(_MSC_VER)
17 // Squelch warnings about dll vs vector and constant conditional expressions
18 # pragma warning (push)
19 # pragma warning (disable: 4251 4127)
20 #endif
21 
22 namespace GeographicLib {
23 
24  /**
25  * \brief Convert between degrees and the %DMS representation
26  *
27  * Parse a string representing degree, minutes, and seconds and return the
28  * angle in degrees and format an angle in degrees as degree, minutes, and
29  * seconds. In addition, handle NANs and infinities on input and output.
30  *
31  * Example of use:
32  * \include example-DMS.cpp
33  **********************************************************************/
35  public:
36 
37  /**
38  * Indicator for presence of hemisphere indicator (N/S/E/W) on latitudes
39  * and longitudes.
40  **********************************************************************/
41  enum flag {
42  /**
43  * No indicator present.
44  * @hideinitializer
45  **********************************************************************/
46  NONE = 0,
47  /**
48  * Latitude indicator (N/S) present.
49  * @hideinitializer
50  **********************************************************************/
51  LATITUDE = 1,
52  /**
53  * Longitude indicator (E/W) present.
54  * @hideinitializer
55  **********************************************************************/
56  LONGITUDE = 2,
57  /**
58  * Used in Encode to indicate output of an azimuth in [000, 360) with no
59  * letter indicator.
60  * @hideinitializer
61  **********************************************************************/
62  AZIMUTH = 3,
63  /**
64  * Used in Encode to indicate output of a plain number.
65  * @hideinitializer
66  **********************************************************************/
67  NUMBER = 4,
68  };
69 
70  /**
71  * Indicator for trailing units on an angle.
72  **********************************************************************/
73  enum component {
74  /**
75  * Trailing unit is degrees.
76  * @hideinitializer
77  **********************************************************************/
78  DEGREE = 0,
79  /**
80  * Trailing unit is arc minutes.
81  * @hideinitializer
82  **********************************************************************/
83  MINUTE = 1,
84  /**
85  * Trailing unit is arc seconds.
86  * @hideinitializer
87  **********************************************************************/
88  SECOND = 2,
89  };
90 
91  private:
92  typedef Math::real real;
93  // Replace all occurrences of pat by c. If c is NULL remove pat.
94  static void replace(std::string& s, const std::string& pat, char c);
95  static const char* const hemispheres_;
96  static const char* const signs_;
97  static const char* const digits_;
98  static const char* const dmsindicators_;
99  static const char* const components_[3];
100  static Math::real NumMatch(const std::string& s);
101  static Math::real InternalDecode(const std::string& dmsa, flag& ind);
102  DMS() = delete; // Disable constructor
103 
104  public:
105 
106  /**
107  * Convert a string in DMS to an angle.
108  *
109  * @param[in] dms string input.
110  * @param[out] ind a DMS::flag value signaling the presence of a
111  * hemisphere indicator.
112  * @exception GeographicErr if \e dms is malformed (see below).
113  * @return angle (degrees).
114  *
115  * Degrees, minutes, and seconds are indicated by the characters d, '
116  * (single quote), &quot; (double quote), and these components may only be
117  * given in this order. Any (but not all) components may be omitted and
118  * other symbols (e.g., the &deg; symbol for degrees and the unicode prime
119  * and double prime symbols for minutes and seconds) may be substituted;
120  * two single quotes can be used instead of &quot;. The last component
121  * indicator may be omitted and is assumed to be the next smallest unit
122  * (thus 33d10 is interpreted as 33d10'). The final component may be a
123  * decimal fraction but the non-final components must be integers. Instead
124  * of using d, ', and &quot; to indicate degrees, minutes, and seconds, :
125  * (colon) may be used to <i>separate</i> these components (numbers must
126  * appear before and after each colon); thus 50d30'10.3&quot; may be
127  * written as 50:30:10.3, 5.5' may be written 0:5.5, and so on. The
128  * integer parts of the minutes and seconds components must be less
129  * than 60. A single leading sign is permitted. A hemisphere designator
130  * (N, E, W, S) may be added to the beginning or end of the string. The
131  * result is multiplied by the implied sign of the hemisphere designator
132  * (negative for S and W). In addition \e ind is set to DMS::LATITUDE if N
133  * or S is present, to DMS::LONGITUDE if E or W is present, and to
134  * DMS::NONE otherwise. Leading and trailing whitespace is removed from
135  * the string before processing. This routine throws an error on a
136  * malformed string. No check is performed on the range of the result.
137  * Examples of legal and illegal strings are
138  * - <i>LEGAL</i> (all the entries on each line are equivalent)
139  * - -20.51125, 20d30'40.5&quot;S, -20&deg;30'40.5, -20d30.675,
140  * N-20d30'40.5&quot;, -20:30:40.5
141  * - 4d0'9, 4d9&quot;, 4d9'', 4:0:9, 004:00:09, 4.0025, 4.0025d, 4d0.15,
142  * 04:.15
143  * - 4:59.99999999999999, 4:60.0, 4:59:59.9999999999999, 4:59:60.0, 5
144  * - <i>ILLEGAL</i> (the exception thrown explains the problem)
145  * - 4d5&quot;4', 4::5, 4:5:, :4:5, 4d4.5'4&quot;, -N20.5, 1.8e2d, 4:60,
146  * 4:59:60
147  *
148  * The decoding operation can also perform addition and subtraction
149  * operations. If the string includes <i>internal</i> signs (i.e., not at
150  * the beginning nor immediately after an initial hemisphere designator),
151  * then the string is split immediately before such signs and each piece is
152  * decoded according to the above rules and the results added; thus
153  * <code>S3-2.5+4.1N</code> is parsed as the sum of <code>S3</code>,
154  * <code>-2.5</code>, <code>+4.1N</code>. Any piece can include a
155  * hemisphere designator; however, if multiple designators are given, they
156  * must compatible; e.g., you cannot mix N and E. In addition, the
157  * designator can appear at the beginning or end of the first piece, but
158  * must be at the end of all subsequent pieces (a hemisphere designator is
159  * not allowed after the initial sign). Examples of legal and illegal
160  * combinations are
161  * - <i>LEGAL</i> (these are all equivalent)
162  * - -070:00:45, 70:01:15W+0:0.5, 70:01:15W-0:0:30W, W70:01:15+0:0:30E
163  * - <i>ILLEGAL</i> (the exception thrown explains the problem)
164  * - 70:01:15W+0:0:15N, W70:01:15+W0:0:15
165  *
166  * \warning The "exponential" notation is not recognized. Thus
167  * <code>7.0E1</code> is illegal, while <code>7.0E+1</code> is parsed as
168  * <code>(7.0E) + (+1)</code>, yielding the same result as
169  * <code>8.0E</code>.
170  *
171  * \note At present, all the string handling in the C++ implementation of
172  * %GeographicLib is with 8-bit characters. The support for unicode
173  * symbols for degrees, minutes, and seconds is therefore via the
174  * <a href="https://en.wikipedia.org/wiki/UTF-8">UTF-8</a> encoding. (The
175  * JavaScript implementation of this class uses unicode natively, of
176  * course.)
177  *
178  * Here is the list of Unicode symbols supported for degrees, minutes,
179  * seconds, and the plus and minus signs; various symbols denoting variants
180  * of a space, which may separate the components of a DMS string, are
181  * removed:
182  * - degrees:
183  * - d, D lower and upper case letters
184  * - U+00b0 degree symbol (&deg;)
185  * - U+00ba masculine ordinal indicator (&ordm;)
186  * - U+2070 superscript zero (⁰)
187  * - U+02da ring above (˚)
188  * - U+2218 compose function (∘)
189  * - * the <a href="https://grid.nga.mil">GRiD</a> symbol for degrees
190  * - minutes:
191  * - ' apostrophe
192  * - ` grave accent
193  * - U+2032 prime (&prime;)
194  * - U+2035 back prime (‵)
195  * - U+00b4 acute accent (&acute;)
196  * - U+2018 left single quote (&lsquo;)
197  * - U+2019 right single quote (&rsquo;)
198  * - U+201b reversed-9 single quote (‛)
199  * - U+02b9 modifier letter prime (ʹ)
200  * - U+02ca modifier letter acute accent (ˊ)
201  * - U+02cb modifier letter grave accent (ˋ)
202  * - seconds:
203  * - &quot; quotation mark
204  * - U+2033 double prime (&Prime;)
205  * - U+2036 reversed double prime (‶)
206  * + U+02dd double acute accent (˝)
207  * - U+201c left double quote (&ldquo;)
208  * - U+201d right double quote (&rdquo;)
209  * - U+201f reversed-9 double quote (‟)
210  * - U+02ba modifier letter double prime (ʺ)
211  * - '&nbsp;' any two consecutive symbols for minutes
212  * - plus sign:
213  * - + plus
214  * - U+2795 heavy plus (➕)
215  * - U+2064 invisible plus (|⁤|)
216  * - minus sign:
217  * - - hyphen
218  * - U+2010 dash (‐)
219  * - U+2011 non-breaking hyphen (‑)
220  * - U+2013 en dash (&ndash;)
221  * - U+2014 em dash (&mdash;)
222  * - U+2212 minus sign (&minus;)
223  * - U+2796 heavy minus (➖)
224  * - ignored spaces:
225  * - U+00a0 non-breaking space
226  * - U+2007 figure space (| |)
227  * - U+2009 thin space (|&thinsp;|)
228  * - U+200a hair space ( | |)
229  * - U+200b invisible space (|​|)
230  * - U+202f narrow space ( | |)
231  * - U+2063 invisible separator (|⁣|)
232  * .
233  * The codes with a leading zero byte, e.g., U+00b0, are accepted in their
234  * UTF-8 coded form 0xc2 0xb0 and as a single byte 0xb0.
235  **********************************************************************/
236  static Math::real Decode(const std::string& dms, flag& ind);
237 
238  /**
239  * Convert DMS to an angle.
240  *
241  * @param[in] d degrees.
242  * @param[in] m arc minutes.
243  * @param[in] s arc seconds.
244  * @return angle (degrees)
245  *
246  * This does not propagate the sign on \e d to the other components,
247  * so -3d20' would need to be represented as - DMS::Decode(3.0, 20.0) or
248  * DMS::Decode(-3.0, -20.0).
249  **********************************************************************/
250  static Math::real Decode(real d, real m = 0, real s = 0)
251  { return d + (m + s / real(Math::ms)) / real(Math::dm); }
252 
253  /**
254  * Convert a pair of strings to latitude and longitude.
255  *
256  * @param[in] dmsa first string.
257  * @param[in] dmsb second string.
258  * @param[out] lat latitude (degrees).
259  * @param[out] lon longitude (degrees).
260  * @param[in] longfirst if true assume longitude is given before latitude
261  * in the absence of hemisphere designators (default false).
262  * @exception GeographicErr if \e dmsa or \e dmsb is malformed.
263  * @exception GeographicErr if \e dmsa and \e dmsb are both interpreted as
264  * latitudes.
265  * @exception GeographicErr if \e dmsa and \e dmsb are both interpreted as
266  * longitudes.
267  * @exception GeographicErr if decoded latitude is not in [&minus;90&deg;,
268  * 90&deg;].
269  *
270  * By default, the \e lat (resp., \e lon) is assigned to the results of
271  * decoding \e dmsa (resp., \e dmsb). However this is overridden if either
272  * \e dmsa or \e dmsb contain a latitude or longitude hemisphere designator
273  * (N, S, E, W). If an exception is thrown, \e lat and \e lon are
274  * unchanged.
275  **********************************************************************/
276  static void DecodeLatLon(const std::string& dmsa, const std::string& dmsb,
277  real& lat, real& lon,
278  bool longfirst = false);
279 
280  /**
281  * Convert a string to an angle in degrees.
282  *
283  * @param[in] angstr input string.
284  * @exception GeographicErr if \e angstr is malformed.
285  * @exception GeographicErr if \e angstr includes a hemisphere designator.
286  * @return angle (degrees)
287  *
288  * No hemisphere designator is allowed and no check is done on the range of
289  * the result.
290  **********************************************************************/
291  static Math::real DecodeAngle(const std::string& angstr);
292 
293  /**
294  * Convert a string to an azimuth in degrees.
295  *
296  * @param[in] azistr input string.
297  * @exception GeographicErr if \e azistr is malformed.
298  * @exception GeographicErr if \e azistr includes a N/S designator.
299  * @return azimuth (degrees) reduced to the range [&minus;180&deg;,
300  * 180&deg;].
301  *
302  * A hemisphere designator E/W can be used; the result is multiplied by
303  * &minus;1 if W is present.
304  **********************************************************************/
305  static Math::real DecodeAzimuth(const std::string& azistr);
306 
307  /**
308  * Convert angle (in degrees) into a DMS string (using d, ', and &quot;).
309  *
310  * @param[in] angle input angle (degrees)
311  * @param[in] trailing DMS::component value indicating the trailing units
312  * of the string (this component is given as a decimal number if
313  * necessary).
314  * @param[in] prec the number of digits after the decimal point for the
315  * trailing component.
316  * @param[in] ind DMS::flag value indicating additional formatting.
317  * @param[in] dmssep if non-null, use as the DMS separator character
318  * (instead of d, ', &quot; delimiters).
319  * @exception std::bad_alloc if memory for the string can't be allocated.
320  * @return formatted string
321  *
322  * The interpretation of \e ind is as follows:
323  * - ind == DMS::NONE, signed result no leading zeros on degrees except in
324  * the units place, e.g., -8d03'.
325  * - ind == DMS::LATITUDE, trailing N or S hemisphere designator, no sign,
326  * pad degrees to 2 digits, e.g., 08d03'S.
327  * - ind == DMS::LONGITUDE, trailing E or W hemisphere designator, no
328  * sign, pad degrees to 3 digits, e.g., 008d03'W.
329  * - ind == DMS::AZIMUTH, convert to the range [0, 360&deg;), no
330  * sign, pad degrees to 3 digits, e.g., 351d57'.
331  * .
332  * The integer parts of the minutes and seconds components are always given
333  * with 2 digits.
334  **********************************************************************/
335  static std::string Encode(real angle, component trailing, unsigned prec,
336  flag ind = NONE, char dmssep = char(0));
337 
338  /**
339  * Convert angle into a DMS string (using d, ', and &quot;) selecting the
340  * trailing component based on the precision.
341  *
342  * @param[in] angle input angle (degrees)
343  * @param[in] prec the precision relative to 1 degree.
344  * @param[in] ind DMS::flag value indicated additional formatting.
345  * @param[in] dmssep if non-null, use as the DMS separator character
346  * (instead of d, ', &quot; delimiters).
347  * @exception std::bad_alloc if memory for the string can't be allocated.
348  * @return formatted string
349  *
350  * \e prec indicates the precision relative to 1 degree, e.g., \e prec = 3
351  * gives a result accurate to 0.1' and \e prec = 4 gives a result accurate
352  * to 1&quot;. \e ind is interpreted as in DMS::Encode with the additional
353  * facility that DMS::NUMBER represents \e angle as a number in fixed
354  * format with precision \e prec.
355  **********************************************************************/
356  static std::string Encode(real angle, unsigned prec, flag ind = NONE,
357  char dmssep = char(0)) {
358  return ind == NUMBER ? Utility::str(angle, int(prec)) :
359  Encode(angle,
360  prec < 2 ? DEGREE : (prec < 4 ? MINUTE : SECOND),
361  prec < 2 ? prec : (prec < 4 ? prec - 2 : prec - 4),
362  ind, dmssep);
363  }
364 
365  /**
366  * Split angle into degrees and minutes
367  *
368  * @param[in] ang angle (degrees)
369  * @param[out] d degrees (an integer returned as a real)
370  * @param[out] m arc minutes.
371  **********************************************************************/
372  static void Encode(real ang, real& d, real& m) {
373  d = int(ang); m = real(Math::dm) * (ang - d);
374  }
375 
376  /**
377  * Split angle into degrees and minutes and seconds.
378  *
379  * @param[in] ang angle (degrees)
380  * @param[out] d degrees (an integer returned as a real)
381  * @param[out] m arc minutes (an integer returned as a real)
382  * @param[out] s arc seconds.
383  **********************************************************************/
384  static void Encode(real ang, real& d, real& m, real& s) {
385  d = int(ang); ang = real(Math::dm) * (ang - d);
386  m = int(ang); s = real(Math::ms) * (ang - m);
387  }
388 
389  };
390 
391 } // namespace GeographicLib
392 
393 #if defined(_MSC_VER)
394 # pragma warning (pop)
395 #endif
396 
397 #endif // GEOGRAPHICLIB_DMS_HPP
Header for GeographicLib::Constants class.
#define GEOGRAPHICLIB_EXPORT
Definition: Constants.hpp:67
GeographicLib::Math::real real
Definition: GeodSolve.cpp:31
Header for GeographicLib::Utility class.
Convert between degrees and the DMS representation.
Definition: DMS.hpp:34
static void Encode(real ang, real &d, real &m)
Definition: DMS.hpp:372
static Math::real Decode(real d, real m=0, real s=0)
Definition: DMS.hpp:250
static std::string Encode(real angle, unsigned prec, flag ind=NONE, char dmssep=char(0))
Definition: DMS.hpp:356
static void Encode(real ang, real &d, real &m, real &s)
Definition: DMS.hpp:384
@ dm
minutes per degree
Definition: Math.hpp:142
@ ms
seconds per minute
Definition: Math.hpp:143
static std::string str(T x, int p=-1)
Definition: Utility.hpp:161
Namespace for GeographicLib.
Definition: Accumulator.cpp:12