[RkWard-devel] Pareto chart and Quality qontrol charts

[Thomas Friedrichsmeier]

Hi Ilias,

On Friday 23 February 2007 20:07, I. Soumpasis wrote:
> I tried the above and I send it as tar.gz file. It does not supress plot
> but prints only the table. If there is a preview window open then user does
> not sees anything, but if it is not, then it pops up a window with the
> plot.
>
> I do not know if this is an acceptable solution, that's why I send it here.
> If you have something other simple go on. Otherwise making a new plugin as
> said above it is an overkill and I do not know how useful it might be.

I see two problems with this approach (only with the "Print plot" option 
unchecked):
1) A plot will always be produced, and there is no way around this using 
pareto.chart(). Of course we can keep it from going to the output, but it 
will still be generated. So this option is a bit confusing, and might 
actually do (slight) harm, if the user has a previous plot in an active 
active device, and then tries to get the descriptives only: He'll get the 
descriptives alright, but also his previous plot will be overwritten.
2) For the case where only descriptives are wanted, using pareto.chart() (as 
and R function) is overkill. Overkill not in the sense of too much work for 
us (as you pointed out, it's a lot less), but in the sense of requiring the 
user to load a package (qcc) that is not actually needed for the job, and 
always does a plot as a side-effect.

> I personally find the plugin as is full of capabilities because most of the
> users will need both plot and results.

Well, and I think this is the bright side of it: There is no urgent need to 
create a second plugin, even though in the long run, I think there should be 
one. For now, your plugin can cover both tasks, even if the second one could 
be handled more efficiently in a separate plugin.

My suggestion: Leave the plugin essentially as is, but remove the "Print plot" 
option again. It's rather confusing, in that a plot is still generated (just 
not added to the output), and that may even be harmful in some situations the 
user should never need to worry about. Rather leave it as a plot with 
the "added value" of also giving the descriptives, if that is wanted.

Note that the comment about using table() from my previous mail still applies 
to this plugin: I think something like this would be needed in this section:

rk.temp.x <- (<? echo ($vars); ?>)
if(is.factor(rk.temp.x)) {
	rk.temp.x <- summary(rk.temp.x)
}

I simply think that in most situations the following:

rk.temp.x <- (<? echo ($vars); ?>)
if(!is.table(rk.temp.x)) {
	rk.temp.x <- table(rk.temp.x)
}

would be closer to the expected result. Currently the plugin works nicely for 
factors, but for vectors it typically does not produce a useful plot. E.g. 
try with these two objects:

a <- rep (c (1, 1, 1, 2, 2, 3), length.out=100)
b <- as.factor (a)

Regards
Thomas
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