[Kst] plotting data in realtime: tips and tricks?

[Timo Juhani Lindfors]

Hi,

"Brisset, Nicolas" <Nicolas.Brisset at eurocopter.com> writes:
> I am not sure I understand what you are trying to do nor do I have
> experience with the stdin source, but I would simply check "count
> from end" and set the vector ranges to 50000 samples, either in the
> wizard (but I guess it does not work for stdin, and there does not

Thanks, this apparently DOES work for stdin too:

perl -e 'use Time::HiRes; my $i = 0; for (;;) { printf("%f\n", sin($i/10000)); $i++; Time::HiRes::usleep(100); }' | sid kst -y 1 stdin

data manager
1 data vector
edit
count from end
range: 50000
ok
close

> seem to be a commandline switch for "count from end") or in the
> Tools -> Change Data Sample Ranges tool menu.  In the worst case,
> you could send the output to an ASCII file and read it with the
> ASCII datasource. It is probably not as good performance-wise due to
> the file I/O operations (unless you write on a ramdisk maybe?) but
> it definitely would allow showing only the last 5 seconds with
> scrolling curves.

Since stdin support seems to work I can now run kst as a 24/7
oscilloscope without having to worry about my hard disk filling up :-)


best regards,
Timo Lindfors