[time-nuts] Lady Heather Question

[Robert Watzlavick.com]

Assuming the vertical scale doesn't change, there should be no change to a particular trace as it scrolls across the screen, even if there is more than one sample per pixel. That's where a peak detect plotting algorithm helps out. Imagine an ink pen plot of some signals then stand back about 10 feet
-instead of the individual points you would just see bands almost like bar graphs. So when plotting to a screen with a finite resolution, for each horizontal pixel location, there are two pixels plotted in the vertical axis with the pixels in between filled in. 

-Bob



On May 2, 2011, at 11:38 AM, Ed Palmer <ed_palmer at sasktel.net> wrote:

> I suspected that the graph issues might be involved with some display resolution issues.  So then if a spike appears and disappears at some point in time, does that mean that in the original data there was a combination of spike and no-spike data and the sub-sampling first picks one and then the other?  But does that mean that the standard deviation values are calculated from the sub-sampled values rather than the original data?
> 
> Thanks,
> Ed
> 
> Mark Sims wrote:
>> When you are viewing a time interval that is longer than one second per screen pixel,  the program must sub-sample the data.  Every second the screen is redrawn with a new set of samples.  Also the plots are rescaled according to the data being plotted (if auto-scaling is turned on).  With very noisy data,  like the raw oscillator plot,  you see the effects of what amounts to a new data set every second.   Turning on display filtering (F D command) helps smooth out the changes (but can hide very short disturbances).                         _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>  
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>