[RkWard-devel] length() and na.rm

[Stefan Rödiger]

Am Donnerstag, 17. August 2006 08:47 schrieb Thomas Friedrichsmeier:
> This points to the underlying problem, that maybe different users expect a
> different answer when they check "length". Probably the safest way out of
> this is this:
>
> - Remove the "NA count" option again.
> - Instead, when user checks "length", three numbers will be produced
> automatically:
> 1) total length
> 2) valid cases
> 3) missing cases (= 1) - 2))
>
> I'm not sure how other systems do this, but this way, we'd be sure to avoid
> confusion. What do you think?

Sounds good. Let's do it this way.
Moreover I wanted to add Skewness and Kurtosis which both are not in stat or 
base but in the  moments package. The way to go would be via require ... . So 
my problem is:
1) is it reasonable to include it as a part of descriptive statistic?

2) if yes, should I use the package or use a formula from a textbook? {if I 
use the package, how can it be handled that the user doesn't need to bother 
where he can get it and will it effect the performance of RKWard in long term 
("load <-> unload, memory usage, ..., stability)}

3) moreover I would like to include "mode" (see 
http://en.wikipedia.org/wiki/Mode_(statistics)) but there is no such function 
from R.

4) last but not least I would like to include the posibility to include 
several plots but in as thumbnail view. We could reuse the code from the 
histogram with  par(mfrow = c(n,m) and a boxplot too. I think this gives a 
good overview of data. (To bad that we don't have (yet ;) ) the svg support, 
this would be great if people want to use these images so thta they can 
resize them and so on).

BTW, I posponed my work on the distribution plug-ins. I struggle a lot with 
the graphic part and at some parts I see problems do due a lack of 
theoretical knowledge from my side. Anyway. Kolmogorov-Smirnov, 
Anderson-Darling and some others are on their way.