Experimental Physics and
Industrial Control System

Hi John and Michael,

Using the rule as Michael described should be the best way to do that, but I think it is not a reasonable to cut the start of the waveform, so I just changed it to cut the end in my code. So in next version of BOY, you should be able to use rule to do this.

For now, there is an alternative way to do that: you can manipulate the data array in script before plotting it. For example, you can only plot an arbitrary subarray of the waveform or only plot the even/odd points. Please see BOY Examples->Miscellaneous->ArraysOperation->PlotFirstNPointsExample.opi

Thanks,
Xihui




> -----Original Message-----
> From: Michael Davidsaver [mailto:[email protected]]
> Sent: Tuesday, February 21, 2012 6:48 PM
> To: [email protected]
> Subject: Re: CSS X-Y Graph
> 
> Hello John,
> 
> I too have had trouble doing this.  I was able to setup a rule to set
> the buffer size from the NORD field of a waveform record.  The result
> was that, when the size was reduced, the start of the waveform was
> removed instead of the end.  So not very useful.
> 
> In the end, as this data was for display only, I "fixed" this by
> padding
> the arrays by repeating the last value.  This at least produces the
> correct visual effect.
> 
> I would welcome a better solution.
> 
> Michael
> 
> 
> On 2/21/2012 4:45 PM, John Dobbins wrote:
> > All,
> >
> > I am trying to create an X-Y graph for displaying a waveform which
> may change in length.
> >
> > A Tech-Talk thread from June 2010
> >
> > http://www.aps.anl.gov/epics/tech-talk/2010/msg00740.php
> >
> > suggests to put a PV into "Buffer Size" . However I am trying to do
> that now (CSS 3.1) and find I can only put an integer into this field,
> not a PV.
> >
> >
> > Taking a step back, is there a recommended approach for displaying a
> waveform which may vary in size. I would like the plot x scale to
> automatically adjust to the new waveform length.
> >
> >
> > Thanks,
> >
> > John Dobbins
> >
> > Cornell University
> 

Replies:

Re: CSS X-Y Graph John Dobbins

References:

CSS X-Y Graph John Dobbins

Re: CSS X-Y Graph Michael Davidsaver

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