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#### 10.6.4 CoordsDegrees

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.

  - Parameters:
    - `deg` (floating point): angle in degrees
  - Return value
    - (String): DMS-format string representing `deg`
`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.

  - Parameters:
    - `deg` (floating point): angle in degrees
    - `secFig` (integer): number of decimal places in the seconds field
  - Return value
    - (String): DMS-format string representing `deg`
`degreesToHms( deg )`
  Converts an angle in degrees to a formatted hours:minutes:seconds string. No fractional part of the seconds field is given.

  - Parameters:
    - `deg` (floating point): angle in degrees
  - Return value
    - (String): HMS-format string representing `deg`
`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.

  - Parameters:
    - `deg` (floating point): angle in degrees
    - `secFig` (integer): number of decimal places in the seconds field
  - Return value
    - (String): HMS-format string representing `deg`
`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.

  - Parameters:
    - `dms` (String): formatted DMS string
  - Return value
    - (floating point): angle in degrees specified by `dms`
`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.

  - Parameters:
    - `hms` (String): formatted HMS string
  - Return value
    - (floating point): angle in degrees specified by `hms`
`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.

  - Parameters:
    - `deg` (floating point): degrees part of angle
    - `min` (floating point): minutes part of angle
    - `sec` (floating point): seconds part of angle
  - Return value
    - (floating point): specified angle in degrees
`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).

  - Parameters:
    - `hour` (floating point): degrees part of angle
    - `min` (floating point): minutes part of angle
    - `sec` (floating point): seconds part of angle
  - Return value
    - (floating point): specified angle in degrees
`skyDistanceDegrees( ra1, dec1, ra2, dec2 )`
  Calculates the separation (distance around a great circle) of two points on the sky in degrees.

  - Parameters:
    - `ra1` (floating point): right ascension of point 1 in degrees
    - `dec1` (floating point): declination of point 1 in degrees
    - `ra2` (floating point): right ascension of point 2 in degrees
    - `dec2` (floating point): declination of point 2 in degrees
  - Return value
    - (floating point): angular distance between point 1 and point 2 in degrees
`posAngDegrees( ra1, dec1, ra2, dec2 )`
  Calculates the position angle between two points on the sky in degrees. The result is in the range +/-180. If point 2 is due east of point 1, the result is +90. Zero is returned if the points are coincident.

  - Parameters:
    - `ra1` (floating point): right ascension of point 1 in degrees
    - `dec1` (floating point): declination of point 1 in degrees
    - `ra2` (floating point): right ascension of point 2 in degrees
    - `dec2` (floating point): declination of point 2 in degrees
  - Return value
    - (floating point): bearing in degrees of point 2 from point 1.
`polarDistanceDegrees( ra1, dec1, radius1, ra2, dec2, radius2 )`
  Calculates the distance in three dimensional space between two points specified in spherical polar coordinates.

  - Parameters:
    - `ra1` (floating point): right ascension of point 1 in degrees
    - `dec1` (floating point): declination of point1 in degrees
    - `radius1` (floating point): distance from origin of point1
    - `ra2` (floating point): right ascension of point 2 in degrees
    - `dec2` (floating point): declination of point2 in degrees
    - `radius2` (floating point): distance from origin of point2
  - Return value
    - (floating point): the linear distance between point1 and point2; units are as for `radius1` and `radius2`

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STILTS - Starlink Tables Infrastructure Library Tool Set
Starlink User Note256
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