[Kst] KST user question re: statistics on sub-range of plot

[nicolas.brisset at free.fr]

Hi John,

I'm sorry that you didn't get an answer earlier (unless I have missed it). We usually answer more quickly.

> I am a KST user, not a developer so I apologize if this is the wrong
> place for me. I was not able to find an active "user forum" specific
> to KST questions, just a generic set of KDE forums.  I'm running KST
> 2.0.3 on Windows XP.
We are planning to open a section on forum.kde.org, but this has not happened yet. Until then the mailing list is the preferred communication means, even though you may get some techie discussion here too...

> Question: is there an easy way to compute average, peak-peak, and RMS
> values for a sub-range of a data set?  For example I have data from
> index 0...1000 but I want to see the statistics on only points
> 200-300.  Zooming in on the data by drawing a rectangle with the
> mouse works so nicely, it would be nice to also select a sub-range
> for stats that way, but manually entering indexes is also workable.
Unfortunately at the time being you have to do it manually, though using the Range tool and/or page-wise scrolling through your data should make it acceptably easy. I'd suggest you create a bugzilla entry for the idea to add an option to dynamically update automatic scalars and other dependents on only the visible data. Sounds feasible...

>  I often want to label plots with avg, rms, p-p values for several
> different selected sub-ranges, corresponding to different states of
> a system at different times, although I have just one large set of
> data which was logged continuously.
Another thing which is planned and should help you is time-indexed access: instead of selecting sample numbers (1000 to 2000) you could say e.g. from 12:30:00.500 to 12:47:00.000. There already is some code for that but it's not finished...

> By the way thanks for making this wonderful program, I use it almost
> every day on sets of several 10s of thousands of points, where Excel
> graphs are either unbearably slow, or it just quits all together.
Nice to hear that you enjoy Kst :-)

Nicolas