# To subscribers of the xforms list from Bill Unruh <firstname.lastname@example.org> :
> Another thing of course is that given a specific screenresolution
> it does not seem to make any sense to try and plot more points in
> a plot than there are pixels. This is also a waste of processing time.
> So what I'm wondering about now is
> whether someone has (already) come up with some sort of
> downsampling paradigm to reduce the number of points to plot
> to the sensible number (i.e. hor. or vert. resolution)
> (avoiding aliasing of course).
You cannot avoid aliasing. 2000 data points into 500 won't go. You have to
decide what it is you would like your displayed data points to actually
show. One possibility which I use is the max and min values of the actual
data between the samples. This basically requires two plots for each
stream-- teh max and the min. However it is up to you to decide which
aspect of the data is most important to you to display.
(See www.theory.physics.ubc.ca/synth.html where I display in a very rough
and ready way the max-min of the data for a sound sample). Other displays
tended to produce severe aliasing on the coarsly sampled data. Note that
this is also what programs like snd do in displaying the sound data.
-- William G. Unruh Canadian Institute for Tel: +1(604)822-3273 Physics&Astronomy Advanced Research Fax: +1(604)822-5324 UBC, Vancouver,BC Program in Cosmology email@example.com Canada V6T 1Z1 and Gravity http://axion.physics.ubc.ca/ For step by step instructions about setting up ppp under Linux, see http://axion.physics.ubc.ca/ppp-linux.html
_________________________________________________ To unsubscribe, send the message "unsubscribe" to firstname.lastname@example.org or see http://bob.usuhs.mil/mailserv/xforms.html XForms Home Page: http://world.std.com/~xforms List Archive: http://bob.usuhs.mil/mailserv/list-archives/
This archive was generated by hypermail 2b29 : Wed Mar 07 2001 - 07:17:55 EST