You are sure you will never get _ and __ as result of calculations? /Erling
Den 2017-09-20 kl. 17:43, skrev Joe Bogner:
I've used _ and __ as placeholders for missing or invalid data. I then
filter them out as needed in calculations. It's simple and has worked out
fine for me.
On Wed, Sep 20, 2017 at 11:22 AM, Erling Hellenäs <[email protected]>
wrote:
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 <
[email protected]>
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,
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
