Strange visualization behavior in Data Browser

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Fri, 03/22/2024 - 12:34 am

Dear Igorians,

 

          yesterday I spent some couple of hours trying to fix a problem which, at the end, was only a visualization problem. Some very sparse matrices (with ca. 0.005% 1s and the rest 0s)  sometimes appear  n the data browser as completely empty. It took me some time to recognize it was not a calculation issue. 

Maybe this could be fixed and avoid time-wasting for other people...

 

Claudio.

There are a number of possible explanations for your observations that depend on the size of the image and the wave's number type.  If you are displaying binary data in an 8-bit wave you may be a victim of an explicit image mode.  You can test that theory by adding one more unique value to the wave (say 2) and then deselect and reselect the wave in the Data Browser.  If you can't explain your observations send us a copy of the wave in an experiment (use the Save Copy button) to support@wavemetrics.com.

AG

March 22, 2024 at 03:01 pm - Permalink

Dear AG,

 

as always, you are right, 8-bit binary data. Adding a 2 changes the display, although 1s are still not visible.

I attached a figure showing the display of the data in the data browser compare to an image of the same data.

Is there any way to fix that?

Thanks, Claudio.

 

 
igordisplay.png

March 28, 2024 at 11:01 am - Permalink

Claudio,

You came across an unfortunate peculiarity of Igor that dates back to the Middle Ages.  Your image is probably in "explicit" mode.  You can turn that mode off using, e.g.,

ModifyImage ddd explicit=0,ctab= {*,*,Grays,0}

I hope this helps,

AG

March 28, 2024 at 03:53 pm - Permalink