[Numpy-discussion] Missing/accumulating data

[Mark Wiebe]

On Tue, Jul 5, 2011 at 11:34 AM, Chris Barker <Chris.Barker at noaa.gov> wrote:

> On 7/3/11 9:03 PM, Joe Harrington wrote:
> > Christopher Barker, Ph.D. wrote
> >> quick note on this: I like the "FALSE == good" way, because:
> >
> > So, you like to have multiple different kinds of masked, but I need
> > multiple good values for counts.
>
> fair enough, maybe there isn't a consensus about what is best, or most
> common, interpretation.
>
> However, I was thinking less "different kinds of masks" than, "something
> special" -- so if there is ANY additional information about a given
> element, it has a non-zero value.
>
> so less "FALSE == good", then "FALSE == raw_value"
>
> seems like the cleanest way to do it.
>
> That having been said, I generally DON'T like the "zero is false"
> convention -- I wish that Python actually required a Boolean where one
> was called, for, rather that being able to pass in zero or any-other-value.
>
> Speaking of which, would we make the NA value be false?
>

For booleans, it works out like this:

http://en.wikipedia.org/wiki/Ternary_logic#Kleene_logic

In R, trying to test the truth value of NA ("if (NA) ...") raises an
exception. Adopting this behavior seems reasonable to me.

-Mark



> -Chris
>
>
> --
> Christopher Barker, Ph.D.
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>
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