How can I draw this ellipse on MatLab
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Mathieu Bouchard
on 15 Feb 2014
Commented: Image Analyst
on 16 Feb 2014
I need to draw this ellipse on Matlab and i can't. My problem seems to be with the plus-minus symbol.
I don't know how to set my axis to get my ellipse right in the middle of my graph !?
It need to be in :
Y = (0:10)
X = (0:8)
This is what i've done so far :
x=0:0.001:8;
y= (((5*(4+-sqrt(8*x-x.^2)))/4));
plot(x,y);
grid on;
I'm using Matlab R2013a
From a student who need your help please !!!!!!
PS : sorry for the silly mistakes, i'm not an anglophone !!
1 Comment
per isakson
on 15 Feb 2014
Edited: per isakson
on 15 Feb 2014
Your code produces half an ellipse.
Matlab doesn't interpret +-sqrt the way you intend.
You can make it two cases and finally concatenate them.
Accepted Answer
Roger Stafford
on 15 Feb 2014
It's easiest to generate an ellipse parametrically. I deduce from your equation for y that the ellipse's equation is:
(x-4)^2/4^2 + (y-5)^2/5^2 = 1
This can be represented parametrically using the parameter t by:
t = linspace(0,2*pi);
x = 4 + 4*cos(t);
y = 5 + 5*sin(t);
plot(x,y)
axis equal
1 Comment
Image Analyst
on 16 Feb 2014
Mathieu, see the FAQ : http://matlab.wikia.com/wiki/FAQ#How_do_I_create_an_ellipse.3F (essentially the same as Roger's code, but there's other good stuff in there that you may like to see and you may benefit from).
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