On Sep 20, 12:36 am, Stan Schymanski <schym...@gmail.com> wrote: > Since this is done in the units package already, is there a way to > formally save the units of e.g. T_a as units.temperature.Kelvin and then > have something like: > sage: T_a = 300 > sage: T_a > 300 Kelvin
You can of course write T_a=300*units.temperature.kelvin and essentially get this, see the doc. Otherwise: python semantics get in the way. What you propose would require T_a to be statically typed to be a temperature, but that is not how python works. The instruction "T_a=300" rebinds the identifier T_a to the object 300 (which, thanks to sage's preparser, really is Integer(300)). Once you execute a new assignment, T_a is bound to a fresh object and all type info hangs off that object, not T_a. T_a=300*units.temperature.kelvin T_a=10*units.length.meter If you want a separate type that denotes temperatures in kelvin, you could define the appropriate (sub)class and get something like: sage: T_a=temperature_in_kelvin(300) #just special printing sage: T_a 300 Kelvin or sage: T_a=temperature_in_kelvin(300) #construct unit expression sage: T_a 300*kelvin but that probably has virtually no benefits for you above what you can already do by just multiplying with the right unit. [Thank you, William, for pointing out that units already subclass symbolic expressions to set docs] [apologies the empty reply before] -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
