Serious Bug in 'Plot Profile' coordinates

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Serious Bug in 'Plot Profile' coordinates

Thiel, Bjoern
Analyzing an image of 3.9 x 3.9 microns (130 x 130 pixels) with a profile plot
I get false coordinates indicating only integer distances (of e.g. 2.0 microns)
while the plots seem to range over fractional distances (of e.g. 2.4 microns).

The reason for it is the rounding in line 184 of ProfilePlot.java
   double length = Math.round(Math.sqrt(dx*dx + dy*dy));
that gives xInc the wrong value.

I'm afraid but this seems to be a serious bug.
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Re: Serious Bug in 'Plot Profile' coordinates

Gabriel Landini
On Thursday 29 Aug 2013 08:11:03 Thiel, Bjoern wrote:
> Analyzing an image of 3.9 x 3.9 microns (130 x 130 pixels) with a profile
> plot I get false coordinates indicating only integer distances (of e.g. 2.0
> microns) while the plots seem to range over fractional distances (of e.g.
> 2.4 microns).

Very odd. Pixel width is 0.0300000... and indeed the plot shows only an
integer maximum values in live mode. This is not the case if you create a new
image and assign a calibration to it.

Note that if I remove the scale from your image:

run("Set Scale...", "distance=0 known=0 pixel=1 unit=pixel");

and then add it again:

run("Properties...", "channels=1 slices=1 frames=1 unit=pixel pixel_width=0.03
pixel_height=0.03 voxel_depth=0.03 frame=[0 sec] origin=0,0");

the scale works as expected.

Also if I create an image, assign that scaling save it and load it again it
still works fine. So far this seems to happen with that image only. I do not
know what is exactly going on, for sure Wayne would nail this bug.

Cheers

Gabriel


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