[Jprogramming] Overflow, underflow, floats

[Erling Hellenäs]

Hi all!

Programs which acted on arrays containing missing data would need 
definitions which accounted for this missing data.  Take a look at R. I 
think most languages have ways of handling missing data, even if 
calculations do not always work directly on arrays containing missing 
data, like they do in R.

We could possibly have arrays of floats containing missing data without 
being able to do all our calculations on these arrays? We already have 
arrays of floats containing NaN, infinity and negative infinity? Would 
it be possible to have some of these NaN floats signal missing data? 
Could arrays with such NaN floats be used in some calculations which 
accounted for this missing data?

Typically when you create report programs, you take care of missing 
data? The user might fill a form, he does not answer to some questions, 
the mean value of an answer for all users is the mean of the values 
filled, but how many and how big percentage are not filled is an 
important part of the result?

Cheers,

Erling

Den 2017-09-20 kl. 16:40, skrev Henry Rich:
> If a list (a) can contain 'missing' entries, what does (# a) mean?  What
> happens to
>
> mean =: +/ % #
>
> ?
>
> How is u/\. a defined?
>
> Henry Rich
>
> On Wed, Sep 20, 2017 at 10:25 AM, Erling Hellenäs <erling at erlinghellenas.se>
> wrote:
>
>> Because you possibly have an array where some cells have missing data and
>> you want to run your functions directly against this array without caring
>> about the possibly missing data. Thats how I think R works. All functions
>> work with cells where the data is missing. Correct me if I'm wrong. R might
>> become the mostly used tool for statistics any day. It might well be worth
>> the effort to look at their solutions if you ask me. /Erling
>>
>> Den 2017-09-20 kl. 12:27, skrev Raul Miller:
>>
>>> Why not just use another number? Many more bits that way...
>>>
>>> Thanks,
>>>
>>>
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