http://imagej.273.s1.nabble.com/Macros-to-read-and-write-Complex-Fourier-Transform-tp3693680p3693688.html
Thanks for helping me with that. I can understand from that code you are
somewhat smaller than the triangle's.
> Here is a macro that creates a square selection that has the same area
> as an existing selection.
>
> getSelectionBounds(x, y, width, height);
> getRawStatistics(area);
> size = sqrt(area);
> x2 = x + width/2 - size/2;
> y2 = y + height/2 - size/2;
> makeRectangle(x2, y2, size, size);
>
> -wayne
>
> On Feb 13, 2009, at 3:27 PM, Hugo A. M. Torres wrote:
>
> > I tried that, didn't work. Maybe I am still having rounding issues
> > because of the area being reported in micrometers.
> >
> > I am not experienced in writing macros, but would it be possible at
> > least in principle to write a macro that specifies a square ROI
> > according to an area value input?
> >
> > Hugo
> >
> > On Fri, 2009-02-13 at 13:41 +0100, joris meys wrote:
> >> Ah, I see. Sorry for the misunderstanding.
> >>
> >> As far as I understand, the ROI measures inside its boundaries,
> >> boundary not
> >> included. So in fact you should extend the length and width of the
> >> ROI with
> >> 2 pixels if you want to have a square that covers the same area. I'm
> >> not
> >> 100% sure about this, but it might be worth a try.
> >>
> >> Kind regards
> >> Joris
> >>
> >> On Fri, Feb 13, 2009 at 1:13 PM, Hugo A. M. Torres
> >> <
[hidden email]>wrote:
> >>
> >>> No Joris, I understand what you are saying, but the problem is the
> >>> first
> >>> ROI (used to measure the nucleus I am interested in) has a triangular
> >>> shape, which will not fit in the background area unless I make it
> >>> into a
> >>> square of the same area as the triangle. Now, this should be very
> >>> straightforward: just draw a square with sides whose lenght is the
> >>> square root of the triangle area. It doesn't work if I use a
> >>> calculator,
> >>> possibly because of rounding issues, I don't know.
> >>>
> >>> I always get a smaller area in um^2 if I do this by hand. So I was
> >>> wandering if it is possible to specify a square ROI by area value.
> >>>
> >>> Any ideas?
> >>>
> >>> Tganks
> >>>
> >>> On Fri, 2009-02-13 at 11:08 +0100, joris meys wrote:
> >>>> The measurements should be fairly simple with the ROI manager. Just
> >>>> click
> >>> on
> >>>> the roi you specified earlier, and drag it to where you want to
> >>>> measure.
> >>>> First click "Add", because otherwise the ROI manager will measure
> >>>> at the
> >>>> previous position. That should give you the results you want.
> >>>>
> >>>> Kind regards
> >>>> Joris
> >>>>
> >>>>
> >>>> On Fri, Feb 13, 2009 at 4:36 AM, Hugo A. M. Torres
> >>>> <
[hidden email]
> >>>> wrote:
> >>>>
> >>>>> Hello listmates,
> >>>>>
> >>>>> I am trying to perform densitometry measurements according to this
> >>>>> method:
> >>>>>
> >>>>> "The nucleus was encircled by free-hand drawing of a border around
> >>>>> the
> >>>>> outermost mRNA-expressing cells in the nucleus. The mean density
> >>>>> and
> >>> the
> >>>>> area of the selection were measured. The mean density of the
> >>>>> background
> >>>>> was measured from a rectangular area of corresponding size in the
> >>>>> immediate vicinity of the nucleus. The mean density of the
> >>>>> background
> >>>>> was subtracted from the mean density of the nucleus and..."
> >>>>>
> >>>>> Now, the problem is I can't specify a ROI of the same area of the
> >>>>> place
> >>>>> I measured previously. I tried taking the square root of the area
> >>> (given
> >>>>> in um^2) and specifying a square ROI with sides of this length but
> >>>>> the
> >>>>> resulting area measured is always smaller!
> >>>>>
> >>>>> Is it possible to specify a square ROI by inputing an area value
> >>>>> in
> >>>>> square micrometers?
> >>>>>
> >>>>> Thanks
> >>>>> --
> >>>>> Hugo Arruda de Moura Torres
> >>>>> ==================================
> >>>>> Departamento de Biofísica
> >>>>> Universidade Federal de São Paulo
> >>>>> Rua Botucatu 862 7o. andar
> >>>>>
> >>> --
> >>
> >>
> >
Rua Botucatu 862 7o. andar