How to create a filled circle?

Question

Thomas Nell 2018-12-28

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/437523-how-to-create-a-filled-circle

评论： Rik 2021-10-2

Hey guys,

I have this function here for drawing circles:

function circles = circle(x,y,r)
hold on
th = 0:pi/50:2*pi;
x_circle = r * cos(th) + x;
y_circle = r * sin(th) + y;
circles = plot(x_circle, y_circle);
hold off

this, however, only draws line circles. What I want to do is draw a filled circle. How do I go about doing this?

Thanks so much!

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Answer 1

Star Strider 2018-12-28

2
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https://ww2.mathworks.cn/matlabcentral/answers/437523-how-to-create-a-filled-circle#answer_354255

在 MATLAB Online 中打开

One option is to use the fill (link) function:

function circles = circle(x,y,r,c)
hold on
th = 0:pi/50:2*pi;
x_circle = r * cos(th) + x;
y_circle = r * sin(th) + y;
circles = plot(x_circle, y_circle);
fill(x_circle, y_circle, c)
hold off
axis equal
end
circleout = circle(3, 4, 2, 'g')            % Call ‘circle’ To Create Green Circle

I added a color argument ‘c’ at the end of your current argument list.

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Answer 2

Nakarin Ratsuntia 2021-10-2

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/437523-how-to-create-a-filled-circle#answer_800014

编辑：Nakarin Ratsuntia 2021-10-2

在 MATLAB Online 中打开

This's some simple way to create filled circle with circle equation.

paper = zeros(360,360); %create empty array
[y x] = size(paper); %define y,x as size of array
r = 40; %define radius of a circle
for i=1:y
    for j=1:x
        if ((i-y/2)^2)+((j-x/2)^2)<(r^2);  %define origin is at the center
            paper(i,j) = 1;  %define array inside the circle eq. = 1
        end
    end
end
imshow(paper);  %show image