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Functions for angle transformations and manipulations, with angles
generally in degrees.
In particular, methods for translating between degrees and HH:MM:SS.S
or DDD:MM:SS.S type sexagesimal representations are provided.
-
degreesToDms( deg )
- Converts an angle in degrees to a formatted degrees:minutes:seconds
string. No fractional part of the seconds field is given.
-
degreesToDms( deg, secFig )
- Converts an angle in degrees to a formatted degrees:minutes:seconds
string with a given number of decimal places in the seconds field.
-
degreesToHms( deg )
- Converts an angle in degrees to a formatted hours:minutes:seconds
string. No fractional part of the seconds field is given.
-
degreesToHms( deg, secFig )
- Converts an angle in degrees to a formatted hours:minutes:seconds
string with a given number of decimal places in the seconds field.
-
dmsToDegrees( dms )
- Converts a formatted degrees:minutes:seconds string to an angle
in degrees. Delimiters may be colon, space, characters
dm[s]
, or some others.
Additional spaces and leading +/- are permitted.
The :seconds part is optional.
-
hmsToDegrees( hms )
- Converts a formatted hours:minutes:seconds string to an angle
in degrees. Delimiters may be colon, space, characters
hm[s]
, or some others.
Additional spaces and leading +/- are permitted.
The :seconds part is optional.
-
dmsToDegrees( deg, min, sec )
- Converts degrees, minutes, seconds to an angle in degrees.
In conversions of this type, one has to be careful to get the
sign right in converting angles which are between 0 and -1 degrees.
This routine uses the sign bit of the deg
argument,
taking care to distinguish between +0 and -0 (their internal
representations are different for floating point values).
It is illegal for the min
or sec
arguments
to be negative.
-
hmsToDegrees( hour, min, sec )
- Converts hours, minutes, seconds to an angle in degrees.
In conversions of this type, one has to be careful to get the
sign right in converting angles which are between 0 and -1 hours.
This routine uses the sign bit of the hour
argument,
taking care to distinguish between +0 and -0 (their internal
representations are different for floating point values).
-
skyDistanceDegrees( ra1, dec1, ra2, dec2 )
- Calculates the separation (distance around a great circle) of
two points on the sky in degrees.
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Next: Activation Functions
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TOPCAT - Tool for OPerations on Catalogues And Tables
Starlink User Note253
TOPCAT web page:
http://www.starlink.ac.uk/topcat/
Author email:
m.b.taylor@bristol.ac.uk
Mailing list:
topcat-user@bristol.ac.uk