python-quantities-developers team mailing list archive

[Tony S Yu <tonyyu@xxxxxxx>]

I'm surprised I didn't notice this before: temperature conversions  
between Celsius and Kelvin don't work correctly.

>>> T = 20 * pq.degC
>>> T.units = pq.K
>>> print T
20.0 K

I'm not sure how to fix this conversion problem, since it requires an  
offset during conversion (which is not yet possible, as far as I can  
tell). In any case, I don't think the above error should pass  
silently. Until, this conversion error is fixed, it'd be nice to  
remove the capability of converting between temperatures (except  
between Rankine and Kelvin, which works fine). Below is a patch that  
does this.

Also, I wanted to follow up on my suggestion for a known issues page.  
I've attached a rough draft of what I had in mind. (Side note: I  
emailed the numpy list about the interpolation issue with zero-rank  
arrays, but it hasn't shown up on the list yet; I'll try again at some  
latter point).

Best,
-Tony

Attachment: issues.rst
Description: Binary data

=== modified file 'quantities/units/temperature.py'
--- quantities/units/temperature.py	2009-06-20 14:21:23 +0000
+++ quantities/units/temperature.py	2009-07-10 19:58:35 +0000
@@ -20,7 +20,6 @@
 )
 degC = celsius = Celsius = UnitTemperature(
     'Celsius',
-    K,
     symbol='degC',
     u_symbol='°C',
     aliases=['degC', 'celsius'],
@@ -31,7 +30,6 @@
 )
 degF = fahrenheit = Fahrenheit = UnitTemperature(
     'Fahrenheit',
-    degR,
     symbol='degF',
     u_symbol='°F',
     aliases=['degF', 'fahrenheit'],