GeographicLib::DMS Class Reference

Convert between degrees and the DMS representation. More...

#include <DMS.hpp>

Public Types
enum	component { DEGREE, MINUTE, SECOND }
enum	flag {   NONE, LATITUDE, LONGITUDE, AZIMUTH,   NUMBER }

Static Public Member Functions
static Math::real	Decode (const std::string &dms, flag &ind)
static Math::real	Decode (real d, real m=0, real s=0)
static Math::real	DecodeAngle (const std::string &angstr)
static Math::real	DecodeAzimuth (const std::string &azistr)
static void	DecodeLatLon (const std::string &dmsa, const std::string &dmsb, real &lat, real &lon, bool longfirst=false)
static std::string	Encode (real angle, component trailing, unsigned prec, flag ind=NONE, char dmssep=char(0))
static std::string	Encode (real angle, unsigned prec, flag ind=NONE, char dmssep=char(0))
static void	Encode (real ang, real &d, real &m)
static void	Encode (real ang, real &d, real &m, real &s)

Private Types
typedef Math::real	real

Private Member Functions
	DMS ()

Static Private Member Functions
static Math::real	InternalDecode (const std::string &dmsa, flag &ind)
static Math::real	NumMatch (const std::string &s)
static void	replace (std::string &s, const std::string &pat, char c)

Static Private Attributes
static const char *const	components_ [3] = {"degrees", "minutes", "seconds"}
static const char *const	digits_ = "0123456789"
static const char *const	dmsindicators_ = "D'\":"
static const char *const	hemispheres_ = "SNWE"
static const char *const	signs_ = "-+"

Detailed Description

Convert between degrees and the DMS representation.

Parse a string representing degree, minutes, and seconds and return the angle in degrees and format an angle in degrees as degree, minutes, and seconds. In addition, handle NANs and infinities on input and output.

Example of use:

// Example of using the GeographicLib::DMS class

#include <iostream>
#include <string>
#include <exception>
#include <GeographicLib/DMS.hpp>

using namespace std;
using namespace GeographicLib;

int main() {
  try {
    {
      string dms = "30d14'45.6\"S";
      DMS::flag type;
      double ang = DMS::Decode(dms, type);
      cout << type << " " << ang << "\n";
    }
    {
      double ang = -30.245715;
      string dms = DMS::Encode(ang, 6, DMS::LATITUDE);
      cout << dms << "\n";
    }
  }
  catch (const exception& e) {
    cerr << "Caught exception: " << e.what() << "\n";
    return 1;
  }
}

Definition at line 34 of file DMS.hpp.

Member Typedef Documentation

typedef Math::real GeographicLib::DMS::real

private

Definition at line 92 of file DMS.hpp.

Member Enumeration Documentation

enum GeographicLib::DMS::component

Indicator for trailing units on an angle.

Enumerator
DEGREE	Trailing unit is degrees.
MINUTE	Trailing unit is arc minutes.
SECOND	Trailing unit is arc seconds.

Definition at line 73 of file DMS.hpp.

enum GeographicLib::DMS::flag

Indicator for presence of hemisphere indicator (N/S/E/W) on latitudes and longitudes.

Enumerator
NONE	No indicator present.
LATITUDE	Latitude indicator (N/S) present.
LONGITUDE	Longitude indicator (E/W) present.
AZIMUTH	Used in Encode to indicate output of an azimuth in [000, 360) with no letter indicator.
NUMBER	Used in Encode to indicate output of a plain number.

Definition at line 41 of file DMS.hpp.

Constructor & Destructor Documentation

GeographicLib::DMS::DMS ( )

private

Member Function Documentation

Math::real GeographicLib::DMS::Decode ( const std::string &  dms, flag &  ind  )

static

Convert a string in DMS to an angle.

Parameters

[in]	dms	string input.
[out]	ind	a DMS::flag value signaling the presence of a hemisphere indicator.

Exceptions

GeographicErr

if dms is malformed (see below).

Returns

angle (degrees).

Degrees, minutes, and seconds are indicated by the characters d, ' (single quote), " (double quote), and these components may only be given in this order. Any (but not all) components may be omitted and other symbols (e.g., the ° symbol for degrees and the unicode prime and double prime symbols for minutes and seconds) may be substituted; two single quotes can be used instead of ". The last component indicator may be omitted and is assumed to be the next smallest unit (thus 33d10 is interpreted as 33d10'). The final component may be a decimal fraction but the non-final components must be integers. Instead of using d, ', and " to indicate degrees, minutes, and seconds, : (colon) may be used to separate these components (numbers must appear before and after each colon); thus 50d30'10.3" may be written as 50:30:10.3, 5.5' may be written 0:5.5, and so on. The integer parts of the minutes and seconds components must be less than 60. A single leading sign is permitted. A hemisphere designator (N, E, W, S) may be added to the beginning or end of the string. The result is multiplied by the implied sign of the hemisphere designator (negative for S and W). In addition ind is set to DMS::LATITUDE if N or S is present, to DMS::LONGITUDE if E or W is present, and to DMS::NONE otherwise. Throws an error on a malformed string. No check is performed on the range of the result. Examples of legal and illegal strings are

• LEGAL (all the entries on each line are equivalent)
  • -20.51125, 20d30'40.5"S, -20°30'40.5, -20d30.675, N-20d30'40.5", -20:30:40.5
  • 4d0'9, 4d9", 4d9'', 4:0:9, 004:00:09, 4.0025, 4.0025d, 4d0.15, 04:.15
  • 4:59.99999999999999, 4:60.0, 4:59:59.9999999999999, 4:59:60.0, 5
• ILLEGAL (the exception thrown explains the problem)
  • 4d5"4', 4::5, 4:5:, :4:5, 4d4.5'4", -N20.5, 1.8e2d, 4:60, 4:59:60

The decoding operation can also perform addition and subtraction operations. If the string includes internal signs (i.e., not at the beginning nor immediately after an initial hemisphere designator), then the string is split immediately before such signs and each piece is decoded according to the above rules and the results added; thus S3-2.5+4.1N is parsed as the sum of S3, -2.5, +4.1N. Any piece can include a hemisphere designator; however, if multiple designators are given, they must compatible; e.g., you cannot mix N and E. In addition, the designator can appear at the beginning or end of the first piece, but must be at the end of all subsequent pieces (a hemisphere designator is not allowed after the initial sign). Examples of legal and illegal combinations are

• LEGAL (these are all equivalent)
  • 070:00:45, 70:01:15W+0:0.5, 70:01:15W-0:0:30W, W70:01:15+0:0:30E
• ILLEGAL (the exception thrown explains the problem)
  • 70:01:15W+0:0:15N, W70:01:15+W0:0:15

Warning

The "exponential" notation is not recognized. Thus 7.0E1 is illegal, while 7.0E+1 is parsed as (7.0E) + (+1), yielding the same result as 8.0E.

Note

At present, all the string handling in the C++ implementation GeographicLib is with 8-bit characters. The support for unicode symbols for degrees, minutes, and seconds is therefore via the UTF-8 encoding. (The JavaScript implementation of this class uses unicode natively, of course.)

Here is the list of Unicode symbols supported for degrees, minutes, seconds, and the sign:

• degrees:
  • d, D lower and upper case letters
  • U+00b0 degree symbol (°)
  • U+00ba masculine ordinal indicator
  • U+2070 superscript zero
  • U+02da ring above
• minutes:
  • ' apostrophe
  • U+2032 prime (′)
  • U+00b4 acute accent
  • U+2019 right single quote (’)
• seconds:
  • " quotation mark
  • U+2033 double prime (″)
  • U+201d right double quote (”)
  • ' ' any two consecutive symbols for minutes
• leading sign:
  • U+2212 minus sign (−)

The codes with a leading zero byte, e.g., U+00b0, are accepted in their UTF-8 coded form 0xc2 0xb0 and as a single byte 0xb0.

Definition at line 28 of file src/DMS.cpp.

static Math::real GeographicLib::DMS::Decode ( real  d, real  m = 0, real  s = 0  )

inlinestatic

Convert DMS to an angle.

Parameters

[in]	d	degrees.
[in]	m	arc minutes.
[in]	s	arc seconds.

Returns

angle (degrees)

This does not propagate the sign on d to the other components, so -3d20' would need to be represented as - DMS::Decode(3.0, 20.0) or DMS::Decode(-3.0, -20.0).

Definition at line 223 of file DMS.hpp.

Math::real GeographicLib::DMS::DecodeAngle ( const std::string &  angstr )

static

Convert a string to an angle in degrees.

Parameters

[in]

angstr

input string.

Exceptions

GeographicErr	if angstr is malformed.
GeographicErr	if angstr includes a hemisphere designator.

Returns

angle (degrees)

No hemisphere designator is allowed and no check is done on the range of the result.

Definition at line 281 of file src/DMS.cpp.

Math::real GeographicLib::DMS::DecodeAzimuth ( const std::string &  azistr )

static

Convert a string to an azimuth in degrees.

Parameters

[in]

azistr

input string.

Exceptions

GeographicErr	if azistr is malformed.
GeographicErr	if azistr includes a N/S designator.

Returns

azimuth (degrees) reduced to the range [−180°, 180°].

A hemisphere designator E/W can be used; the result is multiplied by −1 if W is present.

Definition at line 290 of file src/DMS.cpp.

void GeographicLib::DMS::DecodeLatLon ( const std::string &  dmsa, const std::string &  dmsb, real &  lat, real &  lon, bool  longfirst = false  )

static

Convert a pair of strings to latitude and longitude.

Parameters

[in]	dmsa	first string.
[in]	dmsb	second string.
[out]	lat	latitude (degrees).
[out]	lon	longitude (degrees).
[in]	longfirst	if true assume longitude is given before latitude in the absence of hemisphere designators (default false).

Exceptions

GeographicErr	if dmsa or dmsb is malformed.
GeographicErr	if dmsa and dmsb are both interpreted as latitudes.
GeographicErr	if dmsa and dmsb are both interpreted as longitudes.
GeographicErr	if decoded latitude is not in [−90°, 90°].

By default, the lat (resp., lon) is assigned to the results of decoding dmsa (resp., dmsb). However this is overridden if either dmsa or dmsb contain a latitude or longitude hemisphere designator (N, S, E, W). If an exception is thrown, lat and lon are unchanged.

Definition at line 252 of file src/DMS.cpp.

string GeographicLib::DMS::Encode ( real  angle, component  trailing, unsigned  prec, flag  ind = NONE, char  dmssep = char(0)  )

static

Convert angle (in degrees) into a DMS string (using d, ', and ").

Parameters

[in]	angle	input angle (degrees)
[in]	trailing	DMS::component value indicating the trailing units of the string (this component is given as a decimal number if necessary).
[in]	prec	the number of digits after the decimal point for the trailing component.
[in]	ind	DMS::flag value indicating additional formatting.
[in]	dmssep	if non-null, use as the DMS separator character (instead of d, ', " delimiters).

Exceptions

std::bad_alloc

if memory for the string can't be allocated.

Returns

formatted string

The interpretation of ind is as follows:

• ind == DMS::NONE, signed result no leading zeros on degrees except in the units place, e.g., -8d03'.
• ind == DMS::LATITUDE, trailing N or S hemisphere designator, no sign, pad degrees to 2 digits, e.g., 08d03'S.
• ind == DMS::LONGITUDE, trailing E or W hemisphere designator, no sign, pad degrees to 3 digits, e.g., 008d03'W.
• ind == DMS::AZIMUTH, convert to the range [0, 360°), no sign, pad degrees to 3 digits, e.g., 351d57'.

The integer parts of the minutes and seconds components are always given with 2 digits.

Definition at line 299 of file src/DMS.cpp.

static std::string GeographicLib::DMS::Encode ( real  angle, unsigned  prec, flag  ind = NONE, char  dmssep = char(0)  )

inlinestatic

Convert angle into a DMS string (using d, ', and ") selecting the trailing component based on the precision.

Parameters

[in]	angle	input angle (degrees)
[in]	prec	the precision relative to 1 degree.
[in]	ind	DMS::flag value indicated additional formatting.
[in]	dmssep	if non-null, use as the DMS separator character (instead of d, ', " delimiters).

Exceptions

std::bad_alloc

if memory for the string can't be allocated.

Returns

formatted string

prec indicates the precision relative to 1 degree, e.g., prec = 3 gives a result accurate to 0.1' and prec = 4 gives a result accurate to 1". ind is interpreted as in DMS::Encode with the additional facility that DMS::NUMBER represents angle as a number in fixed format with precision prec.

Definition at line 329 of file DMS.hpp.

static void GeographicLib::DMS::Encode ( real  ang, real &  d, real &  m  )

inlinestatic

Split angle into degrees and minutes

Parameters

[in]	ang	angle (degrees)
[out]	d	degrees (an integer returned as a real)
[out]	m	arc minutes.

Definition at line 345 of file DMS.hpp.

static void GeographicLib::DMS::Encode ( real  ang, real &  d, real &  m, real &  s  )

inlinestatic

Split angle into degrees and minutes and seconds.

Parameters

[in]	ang	angle (degrees)
[out]	d	degrees (an integer returned as a real)
[out]	m	arc minutes (an integer returned as a real)
[out]	s	arc seconds.

Definition at line 357 of file DMS.hpp.

Math::real GeographicLib::DMS::InternalDecode ( const std::string &  dmsa, flag &  ind  )

staticprivate

Definition at line 81 of file src/DMS.cpp.

static Math::real GeographicLib::DMS::NumMatch ( const std::string &  s )

staticprivate

static void GeographicLib::DMS::replace ( std::string &  s, const std::string &  pat, char  c  )

inlinestaticprivate

Definition at line 94 of file DMS.hpp.

Member Data Documentation

const char *const GeographicLib::DMS::components_ = {"degrees", "minutes", "seconds"}

staticprivate

Definition at line 107 of file DMS.hpp.

const char *const GeographicLib::DMS::digits_ = "0123456789"

staticprivate

Definition at line 105 of file DMS.hpp.

const char *const GeographicLib::DMS::dmsindicators_ = "D'\":"

staticprivate

Definition at line 106 of file DMS.hpp.

const char *const GeographicLib::DMS::hemispheres_ = "SNWE"

staticprivate

Definition at line 103 of file DMS.hpp.

const char *const GeographicLib::DMS::signs_ = "-+"

staticprivate

Definition at line 104 of file DMS.hpp.

---

The documentation for this class was generated from the following files:

• DMS.hpp
• src/DMS.cpp