Posted by
ctrueden on
Nov 06, 2015; 3:48pm
URL: http://imagej.273.s1.nabble.com/Setting-values-to-NaN-with-a-macro-tp5014841p5014879.html
Hi all,
On my system [1], the following macro reproduces the issue:
newImage("Untitled", "8-bit black", 400, 400, 1);
run("32-bit");
makeRectangle(83, 88, 235, 228);
setForegroundColor(50, 50, 50);
run("Draw");
run("Macro...", "code=[if (v==0) v=NaN]");
print("(1, 1) = " + getPixel(1, 1));
It outputs the line:
(1, 1) = 0
But I would expect it to read:
(1, 1) = NaN
Regards,
Curtis
[1] ImageJ 2.0.0-rc-41/1.50d; Java 1.8.0_45 [64-bit])
On Fri, Nov 6, 2015 at 9:40 AM, Rasband, Wayne (NIH/NIMH) [E] <
[hidden email]> wrote:
> > On Nov 6, 2015, at 4:40 AM, james_minto <
[hidden email]> wrote:
> >
> > james_minto wrote
> >> In versions 1.44p and earlier, I could set zero values as NaN (not a
> >> number) with the following macro:
> >>
> >> if(v==0)v=NaN;
> >>
> >> In version 1.50d this does not work (no change to the image), but it
> also
> >> doesn't give an error message. This problem happens for all image types
> >> I've tested (8-bit, 32-bit, RGB) and in both Fiji and plain ImageJ.
> >>
> >> Has the syntax for defining NaN changed at some point between version
> >> 1.44p and 1.50d?
> >>
> >> Does any one know of an alternative method to set pixels than meet a
> >> certain criteria as NaN?
>
> This test macro
>
> v = 0;
> if (v==0)
> v=NaN;
> print(v);
>
> outputs “NaN” on my Mac with both Java 1.6.0_65 and Java 1.8.0_60. 32-bit
> (float) images are the only image type that support NaN pixel values.
> Pixels in 8-bit images can only have integer values in the range 0 to 255.
>
> -wayne
> >
>
> > The change in NaN behavior occurs between ImageJ version 1.50a and 1.50d
> (I
> > haven't yet tried the intermediate versions to find out exactly where)
> and
> > also with java versions 1.6, 1.7 and OpenJDK8.
> >
> > If I create an 8-bit image with a block of 255 and a value of 1
> everywhere
> > else, then run the macro if(v==1)v=NaN, the 255 remains unchanged whilst
> the
> > 1 is set to 0, not NaN.
> >
> > Would anyone by able to test if they get the same behaviour with their
> > setup?
> >
> > Cheers
> >
> > James
> >
> > --
> > View this message in context:
>
http://imagej.1557.x6.nabble.com/Setting-values-to-NaN-with-a-macro-tp5014841p5014873.html> > Sent from the ImageJ mailing list archive at Nabble.com.
>
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