UnitConverter

astropy.wcs.UnitConverter(*args, **kwargs) [edit on github]

Deprecated since version 0.2: Use astropy.units instead.

UnitConverter(have, want, translate_units=’‘)

An object for converting from one system of units to another.

Use the returned object’s convert method to convert values from have to want.

This function is permissive in accepting whitespace in all contexts in a units specification where it does not create ambiguity (e.g. not between a metric prefix and a basic unit string), including in strings like "log (m ** 2)" which is formally disallowed.

Note

Deprecated in Astropy 0.2

UnitConverter will be removed in a future version of astropy. The astropy.units package should be used instead.

Parameters :

have : string

FITS unit string to convert from, with or without surrounding square brackets (for inline specifications); text following the closing bracket is ignored.

want : string

FITS unit string to convert to, with or without surrounding square brackets (for inline specifications); text following the closing bracket is ignored.

ctrl : string, optional

Do potentially unsafe translations of non-standard unit strings.

Although "S" is commonly used to represent seconds, its recognizes "S" formally as Siemens, however rarely that may be translation to "s" is potentially unsafe since the standard used. The same applies to "H" for hours (Henry), and "D" for days (Debye).

This string controls what to do in such cases, and is case-insensitive.

  • If the string contains "s", translate "S" to "s".
  • If the string contains "h", translate "H" to "h".
  • If the string contains "d", translate "D" to "d".

Thus '' doesn’t do any unsafe translations, whereas 'shd' does all of them.

Raises :

ValueError :

Invalid numeric multiplier.

SyntaxError :

Dangling binary operator.

SyntaxError :

Invalid symbol in INITIAL context.

SyntaxError :

Function in invalid context.

SyntaxError :

Invalid symbol in EXPON context.

SyntaxError :

Unbalanced bracket.

SyntaxError :

Unbalanced parenthesis.

SyntaxError :

Consecutive binary operators.

SyntaxError :

Internal parser error.

SyntaxError :

Non-conformant unit specifications.

SyntaxError :

Non-conformant functions.

ValueError :

Potentially unsafe translation.

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