Line selection

[Marie Lee]

Hi everyone!

I am new to ImageJ and to the list. I have recorded a macro and have one
question about line selections:

setAutoThreshold();
//run("Threshold...");
setThreshold(84, 156);
run("Create Selection");
run("Set Measurements...", "  center fit limit redirect=None decimal=3");
run("Measure");

The macro finds the center of mass. Now I would like to make a line
selection (the selection can be from the top of the image to the bottom)
that depends on the angle I get in the result table:

1    165.730    146.588    298.355    217.499    156.694

So in this case I would like to have a line selection that goes from the top
of the image to the bottom- with an angle of 156.694. (I hope that I
understood the imageJ documentation right- so that the angle I get is the
angle between the primary axis (when fitting the ellipse) and a line
parallell to the x-axis of the image)

Is there any easy way to do it? Can I do it in a macro? Is there any plugins
or macros that already works for selections that depends on the angle?

Thanks in advance

Marie Lee