MATLAB: To plot an ellipse

ellipse

Hi,

I have got the semi axes, with that how to plot an ellipse in matlab. I have tried using the function 'pdeellip', but it didn't work out. Please do help.

Thanks in advance.

Best Answer

See the FAQ: http://matlab.wikia.com/wiki/FAQ#How_do_I_create_an_ellipse.3F

Related Solutions

MATLAB: How to obtain an angular segment with its vertex on the center from a circular image

See the third example in the FAQ http://matlab.wikia.com/wiki/FAQ#How_do_I_create_a_circle.3F

xCenter = 12;
yCenter = 10;
theta = 0 : 0.01 : 2*pi;
radius = 5;
x = radius * cos(theta) + xCenter;
y = radius * sin(theta) + yCenter;
plot(x, y);
axis square;
xlim([0 20]);
ylim([0 20]);
grid on;

Adjust the starting and ending theta to be what you need them to be, then pass x and y into poly2mask() to get a binary image which can then multiply by your image.

mask = poly2mask(x,y,size(rgbImage, 1), size(rgbImage, 2));
% Mask the image using bsxfun() function
maskedRgbImage = bsxfun(@times, rgbImage, cast(mask, class(rgbImage)));

MATLAB: Plot ellipsoids with an azimuth angle

YOu may rotate the ellipse at desired angle using rotation matrix.

xCenter = 12.5;
yCenter = 10;
xRadius = 2.5;
yRadius = 8;
theta = 0 : 0.01 : 2*pi;
%theta= 70
x = xRadius * cos(theta) + xCenter;
y = yRadius * sin(theta) + yCenter;
plot(x, y,'r-', 'LineWidth', 3);
T = 70*pi/180 ;
R = [cos(T) -sin(T) ;
    sin(T)   cos(T) ] ;
P = [x ; y] ;
P1 = R*(P-mean(P,2))+mean(P,2) ;
x1 = P1(1,:) ; 
y1 = P(2,:) ;
hold on
plot(x1,y1,'b')

Best Answer

Related Solutions

MATLAB: How to obtain an angular segment with its vertex on the center from a circular image

MATLAB: Plot ellipsoids with an azimuth angle

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