Comments on: Fitting a Circle, easily.

By: bshoelso

bshoelso — Tue, 24 Jan 2012 21:33:22 +0000

See my reply to ko’s ellipse-fitting question earlier.

By: payday loans

payday loans — Tue, 24 Jan 2012 21:27:09 +0000

What if I wanted to fit it into an oval. How would that work?

By: Web Design

Web Design — Tue, 01 Mar 2011 17:53:08 +0000

I then hope to use this circlefit.m to give a diameter estimate of each circle.

By: Brett

Brett — Sat, 23 Oct 2010 14:31:29 +0000

Motahhare,
I don’t know why that link is no longer valid; perhaps the author pulled the file. However, if you search the File Exchange for “fit circle,” you should find several options that will do what you need.

By: Motahhare

Motahhare — Fri, 22 Oct 2010 20:45:23 +0000

Hi
I have the same problem as nadine had,but the link which Bob was given is now corrupt & I can’t find a good answer.
would you help me please?!
tnx

By: Brett

Brett — Mon, 18 Oct 2010 14:50:54 +0000

Quinno,
In a “Hough” world, one would have to parameterize the rectangle or polynomial and create the Hough implementation himself or herself. But the MATLAB function POLYFIT might be useful for you as well.

By: Quinno

Quinno — Mon, 19 Jul 2010 12:19:01 +0000

I would like to create a best-fit rectangle to a object or polygon. how can i do that?

By: Bill

Bill — Thu, 23 Apr 2009 03:01:19 +0000

CIRCLES
9 circles .
Each Circle lettered, A through I, has it’s own number value from 1 through 9.Sums of circles that overlap at that point.
for example… 5 is the sum of circles A and C. What are A and C’s Values?
How do you arrive at the values?

By: Brett

Brett — Mon, 19 Jan 2009 19:29:35 +0000

BWBOUNDARIES operates on a binary image. If possible, I would avoid the route of converting your raw data to an image file if the only reason for doing so would be extracting and fitting the data for overlapping circles in preparation for re-plotting them.

I haven’t seen your data, but my initial thought is use some other (clustering?) approach on the raw data to associate points with one of the two circles, then fitting them independently.

If you do need to extract xs and ys from the output of BWBOUNDARIES (which returns a cell array of x-y- data), you can easily do so. For instance, the boundaries of the first object in the bw image IMG can be plotted with:

b = bwboundaries(img);
figure;
plot(b{1}(:,1),b{1}(:,2),’r.’);

Cheers,
Brett

By: Lee

Lee — Mon, 19 Jan 2009 16:44:28 +0000

“If I recall my geometry, one would calculate the diameter of the best-fit circle by doubling the best-fit radius” – now thats just cheeky. funny though:)

Ah, if this outputs radius values then I shouldn’t have a problem. great!

But before i get that far, I’m attempting to determine diameter values from 2 overlapping circles. I am trying to use BWBOUNDARIES to extract arc values from the areas of the circles that are not overlapping. I then hope to use this circlefit.m to give a diameter estimate of each circle.

Can you help me with extracting the required values from bwboundaries to insert as my input to circlefit.m, if you get my drift? bwboundaries just outputs an array and not the raw data if im correct?

thank you:)

lee