Bug 249555 - Bogus front to back line on live plot
Summary: Bogus front to back line on live plot
Status: RESOLVED NOT A BUG
Alias: None
Product: kst
Classification: Applications
Component: plotting (show other bugs)
Version: 2.0.0
Platform: Compiled Sources Linux
: NOR normal
Target Milestone: 2.0.0
Assignee: kst
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-08-30 23:31 UTC by Peter Milne
Modified: 2010-11-12 10:42 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:


Attachments
Picture shows the "diagonal line" fault (83.44 KB, image/png)
2010-08-30 23:31 UTC, Peter Milne
Details
showing the fault relates to timebase (55.02 KB, image/png)
2010-08-30 23:33 UTC, Peter Milne
Details

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Description Peter Milne 2010-08-30 23:31:31 UTC
Created attachment 51123 [details]
Picture shows the "diagonal line" fault

Version:           2.0.0
OS:                Linux

Running a live plot, last 100 points in a long trace with >1 update per second.
Approx 1 in 10 plots show a fault where it appears that a straight line is drawn back from the right-most point to the left most point.
This appears as  "Diagonal Line" in noisy data. 
The rest of the plots are fine

Reproducible: Always

Steps to Reproduce:
Plot live data. Watch. Finger on the pause button to catch it ..



Looks like it's related to timebase.
Plotting data vs index, the fault doesn't happen.

The generator program updates data first, then timebase...
maybe we'd get better results if it were to write timebase before data?.
Comment 1 Peter Milne 2010-08-30 23:33:14 UTC
Created attachment 51124 [details]
showing the fault relates to timebase

Top two plots vs INDEX are good.
Bottom two plots vs TB show the line fault.
Comment 2 Netterfield 2010-08-31 00:04:11 UTC
This looks like a synchronization issue with the dirfile, where the X axis vector hasn't yet been written to yet...  

Can you look at 
http://getdata.sourceforge.net/dirfile.html#reffield
and make sure that your dirfile is being written to correctly?  (basically, you need to make sure that the "reference field" is written to last.)
Comment 3 Peter Milne 2010-08-31 10:08:55 UTC
Correcting the DirFile generation as per comment 2 eliminates the fault.
So this was a fault in user code, not KST or DirFile.
Comment 4 Peter Kümmel 2010-11-12 10:42:50 UTC
These bugs are solved with 2.0.0