Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.

Topic: How to find the area for two overlapped pattern?
Replies: 6   Last Post: May 3, 2012 6:14 PM

 Messages: [ Previous | Next ]
 Sheng Yuan Posts: 4 Registered: 5/2/12
Re: How to find the area for two overlapped pattern?
Posted: May 3, 2012 2:39 AM

Thanks for the information. I thought what was described in the problem is a Convolution operation? Need to write the check-board patterns into a matrix (maybe a 60 X 48 matrix? ) with 0s (black square) and 1s (white square), and somehow write the circle as a matrix also (all element=1 inside, not sure how this can be done properly).

After the matrix is built, as the circle is drag along the check-board by 640 steps, the transmissive area of the check-board fall into the 3mm circle will the convolution of the two matrix?

Need help on how to build the matrix and get a [640 X 480] matrix as the out put though.

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <jnt7e3\$p9h\$1@newscl01ah.mathworks.com>...
> "Sheng Yuan" wrote in message <jnsnrb\$off\$1@newscl01ah.mathworks.com>...
> > Hello all,
> >
> > I have a 60mm X 48 mm area with transmissive and absorbing little squares (1mm in x and y size), like a black and white checkboard (the white as sqaure as transmissive)
> >
> > I have another pattern which is an open circle (transmissive) with 3mm in diameter.
> >
> > I now overlap the two patterns (puting the circle at the upleft corner of the checkboard pattern) and drag the 3mm diameter circle accorss the checkboard along the 60mm long direction, in 640 steps, from one end to the other end.
> >
> > I want to know as I draw the open circle accorss the blank and white little sqaures, at each step, what is the total transmissive area (will be a single number) on the checkboard fall into the 3mm diameter clear circle I am draging?
> >
> > Anyone can help on how to do this coding in matlab?
> >
> > Thanks!

>
> You can discretize the circle as a polygon with fine edges, then use tool such as this to compute the overlap area
> http://www.mathworks.com/help/toolbox/map/ref/polybool.html
>
> Then use polyarea() to compute the surface.
>
> If you don't own mappin toolbox, you can find a replacement on FEX such as
>
> http://www.mathworks.com/matlabcentral/fileexchange/36241-polygon-clipping-and-offsetting
>
> Bruno

Date Subject Author
5/2/12 Sheng Yuan
5/3/12 Bruno Luong
5/3/12 Sheng Yuan
5/3/12 Sheng Yuan
5/3/12 ImageAnalyst
5/3/12 Sheng Yuan
5/3/12 ImageAnalyst