[Tutor] class uncertainty

[Roeland Rengelink]

Roeland Rengelink wrote:
> 
> Christopher Smith wrote:
> >
> > I've created a class which keeps track of the uncertainty in a number and
> > subsequent calculations performed with that number.  It works like this:

[snip]

> >
> > def log(x):
> >         if type(x)==<the type of my class>:
> >                 return uncertain.log(x)
> >         return math.log(x)
> >
> > I would prefer the latter so the operation is as seamless as possible.
> > That's where I need the advise, though.
> >
> 
> I think this is a good solution.
> 

Where I was assuming you meant something like:

def log(x):
    if isinstance(x, uncertain):
        return x.log()
    else:
        return math.log(x)

with

class uncertain:
    ...
    def log(self):
        ...return uncertain log...
  
So that module uncertain provides  

- a log function that can take both exact and uncertain numbers as
argument
- an uncertain class that knows how to do a log of an uncertain number.

Hope this helps,

Roeland
-- 
r.b.rigilink@chello.nl

"Half of what I say is nonsense. Unfortunately I don't know which half"