Conversion between sexagesimal and decimal coordinate representation¶
The routines below convert between sexagesimal and decimal coordinate representations.
Warning
Until (and including) version 0.11.0, the sign of declinations starting with ‘-00’ was not handled correctly.
Example: Convert between decimal and sexagesimal representation¶
from __future__ import print_function, division
from PyAstronomy import pyasl
# Coordinates of HD 1 from SIMBAD
hd1 = "00 05 08.83239 +67 50 24.0135"
print("Coordinates of HD 1 (SIMBAD): ", hd1)
# Obtain decimal representation
ra, dec = pyasl.coordsSexaToDeg(hd1)
print("Coordinates of HD 1 [deg]: %010.6f %+09.6f" % (ra, dec))
# Convert back into sexagesimal representation
sexa = pyasl.coordsDegToSexa(ra, dec)
print("Coordinates of HD 1 [sexa]: ", sexa)
Routines¶
- PyAstronomy.pyasl.coordsSexaToDeg(c, fullOut=False)¶
Convert sexagesimal coordinate string into degrees.
- Parameters
- cstring
The coordinate string. Valid formats are, e.g., “00 05 08.83239 +67 50 24.0135” or “00:05:08.83239 -67:50:24.0135”. Spaces or colons are allowed as separators for the individual components of the coordinates.
- fullOutboolean, optional
If True, two additional tuples holding the individual components of the right ascension and declination specification will be returned. The default is False.
- Returns
- ra, decfloat
Right ascension and declination in degrees.
- hms, dmstuples of three floats
If fullOut is True, two tuples of three numbers each will be returned, which hold the individual constituents making up the right ascension (hms) and declination (dms) specifiers in sexagesimal representation.
- PyAstronomy.pyasl.coordsDegToSexa(ra, dec, asString=True, fmt=('%02d %02d %06.3f ', '%s%02d %02d %06.3f'))¶
Convert right ascension and declination from degrees into sexagesimal representation.
- Parameters
- rafloat
Right ascension in degrees.
- decfloat
Declination in degrees.
- asStringboolean, optional
If True (default), the result will be a string formatted according to the rules specified by fmt.
- fmttuple of strings, optional
The output format used to create the output string (first ra, second dec). Only used if asString is True (default).
- Returns
- Coordinatesstring or tuple
If asString is True (default), a string holding the coordinates is returned, which is formatted according to the rules specified by the fmt parameter. If False, a tuple of two tuples is returned, of which the first holds three numbers representing the right ascension (hms) and the second three numbers representing the declination (dms, sign).
- PyAstronomy.pyasl.hmsToDeg(h, m, s)¶
Convert hour-minute-second specification into degrees.
- Parameters
- hfloat
Hours (0-24)
- mfloat
Minutes (time, 0-60)
- sfloat
Seconds (time, 0-60)
- Returns
- Anglefloat
The corresponding angle in degrees.
- PyAstronomy.pyasl.degToHMS(d)¶
Convert degrees into time units (hours-minutes-seconds)
- Parameters
- dfloat
Degrees (0-360)
- Returns
- h, m, s: float
Hours, minutes, and seconds
- PyAstronomy.pyasl.dmsToDeg(d, m, s, esign=0)¶
Convert degree-arcminute-arcsecond specification into degrees.
- Parameters
- dfloat
Degrees.
- mfloat
Arcminutes (0-60)
- sfloat
Arcseconds (0-60)
- esignint, optional, {-1,0,1}
Explicit sign with -1 representing negative sign, +1 representing positive sign, and 0 indicating no explicit sign specification. The explicit sign is necessary if negative southern coordinates are specified but d is 0 and, thus, cannot carry the sign.
- Returns
- Anglefloat
The corresponding angle in degrees.
- PyAstronomy.pyasl.degToDMS(g)¶
Convert degrees into arc units (degrees, (arc)minutes, (arc)seconds)
- Parameters
- gfloat
Value in degrees.
- Returns
- d, m, s, signfloat, int
Degrees, (arc)minutes, and (arc)seconds. Note that only the degree number is signed. The sign (+1/-1) is also returned to yield a complete result if the value of degree (d) is zero.
