# Drawing a segment of a circle

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Bojan on 27 Apr 2011
Commented: zain ul haq on 23 Dec 2019
I would like to draw a segment of a circle (like a slice of a pizza) but cannot find an easy way to do it.
I am currently drawing triangles using fill function but ideally I need one side of the triangle to be curved. Is there a way to specify a curvature of a line? Thanks B

the cyclist on 27 Apr 2011
There are several files in the File Exchange that will do what you want. Here is one:
Also, here is a simple function that could be modified to draw just a segment:
function h = circle(x,y,r,nsegments)
if nargin<4
nsegments=50;
end
hold on
th = 0:2*pi/nsegments:2*pi;
xunit = r * cos(th) + x;
yunit = r * sin(th) + y;
h = plot(xunit, yunit);
hold off
end

#### 1 Comment

poonam tailor on 31 Jan 2015
Sir i need sector's center point. As i need a mid region of a circles sector for cluster head selection.

Matt Fig on 27 Apr 2011
Here is another function to do it. It returns the handle to the patch object so that the color can be set or whatever.
function P = plot_arc(a,b,h,k,r)
% Plot a circular arc as a pie wedge.
% a is start of arc in radians,
% b is end of arc in radians,
% (h,k) is the center of the circle.
% Try this: plot_arc(pi/4,3*pi/4,9,-4,3)
% Author: Matt Fig
t = linspace(a,b);
x = r*cos(t) + h;
y = r*sin(t) + k;
x = [x h x(1)];
y = [y k y(1)];
P = fill(x,y,'r');
axis([h-r-1 h+r+1 k-r-1 k+r+1])
axis square;
if ~nargout
clear P
end
Now from the command line:
P = plot_arc(pi/4,3*pi/3,9,-4,3);
set(P,'edgecolor','b','linewidth',4)

Bojan on 27 Apr 2011
Perfect, exactly what I need
B
Ron Beck on 26 Feb 2018
Is it possible to have a curve at the bottom instead of a point?
zain ul haq on 23 Dec 2019
Sir, can I plot the segmet with height too, I need to plot like a 3d slice of a cake