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Wed, 23 Jan 2013 16:31:08 +0000
how to find the points inside a curvature shape
http://www.mathworks.com/matlabcentral/newsreader/view_thread/326008#896110
Tinith
Hi, i have a polygon (e.g: rectangle) where it has equally spaced points (coordinates are known) inside it. then i need to draw a curvature shape (e.g: clothoid cuve, ellipse) inside this polygon. what i want to achieve is to find the coordinates of the points which is covered by the curvature shape.

Wed, 23 Jan 2013 18:12:08 +0000
Re: how to find the points inside a curvature shape
http://www.mathworks.com/matlabcentral/newsreader/view_thread/326008#896125
Roger Stafford
"Tinith " <snoopcat@live.com> wrote in message <kdp38c$d9g$1@newscl01ah.mathworks.com>...<br>
> Hi, i have a polygon (e.g: rectangle) where it has equally spaced points (coordinates are known) inside it. then i need to draw a curvature shape (e.g: clothoid cuve, ellipse) inside this polygon. what i want to achieve is to find the coordinates of the points which is covered by the curvature shape. <br>
         <br>
If by "shape" you mean the region enclosed by a closed curve, then use the inequality available from the equation of that curve. For an ellipse with equation <br>
<br>
A*x^2+B*x*y+C*y^2+D*x+E*y+F = 0 <br>
<br>
you would test your points with the inequality<br>
<br>
sign(A)*(A*x^2+B*x*y+C*y^2+D*x+E*y+F) <= 0<br>
<br>
With a clothoid curve (cornu or Euler spiral), which is not a closed curve, I have no idea what it would be that you want. It has no inside or outside, only points along an infinitely thin curve. What would you call its "shape"?<br>
<br>
Roger Stafford

Thu, 24 Jan 2013 00:33:09 +0000
Re: how to find the points inside a curvature shape
http://www.mathworks.com/matlabcentral/newsreader/view_thread/326008#896172
Tinith
"Roger Stafford" wrote in message <kdp95o$8k1$1@newscl01ah.mathworks.com>...<br>
> "Tinith " <snoopcat@live.com> wrote in message <kdp38c$d9g$1@newscl01ah.mathworks.com>...<br>
> > Hi, i have a polygon (e.g: rectangle) where it has equally spaced points (coordinates are known) inside it. then i need to draw a curvature shape (e.g: clothoid cuve, ellipse) inside this polygon. what i want to achieve is to find the coordinates of the points which is covered by the curvature shape. <br>
>          <br>
> If by "shape" you mean the region enclosed by a closed curve, then use the inequality available from the equation of that curve. For an ellipse with equation <br>
> <br>
> A*x^2+B*x*y+C*y^2+D*x+E*y+F = 0 <br>
> <br>
> you would test your points with the inequality<br>
> <br>
> sign(A)*(A*x^2+B*x*y+C*y^2+D*x+E*y+F) <= 0<br>
> <br>
> With a clothoid curve (cornu or Euler spiral), which is not a closed curve, I have no idea what it would be that you want. It has no inside or outside, only points along an infinitely thin curve. What would you call its "shape"?<br>
> <br>
> Roger Stafford<br>
<br>
<br>
I am trying to generate a shape which looks like an antenna lobe. It is similar to a ellipse. But not perfect as an ellipse.

Thu, 24 Jan 2013 03:38:08 +0000
Re: how to find the points inside a curvature shape
http://www.mathworks.com/matlabcentral/newsreader/view_thread/326008#896179
Roger Stafford
"Tinith " <snoopcat@live.com> wrote in message <kdpvg5$4gt$1@newscl01ah.mathworks.com>...<br>
> I am trying to generate a shape which looks like an antenna lobe. It is similar to a ellipse. But not perfect as an ellipse. <br>
        <br>
In that case the answer to your question will depend on just how you generate your shape. How do you generate it?<br>
<br>
Roger Stafford

Thu, 24 Jan 2013 11:54:07 +0000
Re: how to find the points inside a curvature shape
http://www.mathworks.com/matlabcentral/newsreader/view_thread/326008#896191
Tinith
"Roger Stafford" wrote in message <kdqab0$a90$1@newscl01ah.mathworks.com>...<br>
> "Tinith " <snoopcat@live.com> wrote in message <kdpvg5$4gt$1@newscl01ah.mathworks.com>...<br>
> > I am trying to generate a shape which looks like an antenna lobe. It is similar to a ellipse. But not perfect as an ellipse. <br>
>         <br>
> In that case the answer to your question will depend on just how you generate your shape. How do you generate it?<br>
> <br>
> Roger Stafford<br>
<br>
<br>
at the moment i am generating the beam patterns using DIGITAL BEAMFORMING<br>
by King Fisher, which can be found in: <a href="http://www.mathworks.co.uk/matlabcentral/fileexchange/13864digitalbeamforming">http://www.mathworks.co.uk/matlabcentral/fileexchange/13864digitalbeamforming</a>