How to have a function return a coordinate point?

I am trying to get a function to return (x,y) coordinates for a given angle theta. I am struggling to figure out how to get the output of the function to be coordinate points and not two seperate variables x and y.
This is what I have for the function:
function [x,y] = unitCircle(theta)
[x,y] = [cos(theta),sin(theta)]
end
And when I call the function using:
[x,y] = unitCircle(pi/4)
I get an error:
Too many output arguments.
Error in unitCircle (line 2)
[x,y] = [cos(theta),sin(theta)]

1 Comment

function [x,y] = unitCircle(theta)
x = cos(theta);
y = sin(theta);
end

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 Accepted Answer

[x,y] = unitCircle(pi/4)
x = 0.7071
y = 0.7071
function [x y] = unitCircle(theta)
z = [cos(theta),sin(theta)];
x = z(1);
y = z(2);
end

4 Comments

There is an error in your accepted answer (proposed by Torsten). Note this code is not consistent and does not deliver (solve) for all possible values of theta. Wrong.
theta = -pi:.1:pi;
[x,y]=unitCircle(theta)
function [x y] = unitCircle(theta)
z = [cos(theta),sin(theta)];
x = z(1);
y = z(2);
end
This function file syntax has to be:
theta = -pi:.1:pi;
[x,y]=unitCircle(theta)
x = 1×63
-1.0000 -0.9950 -0.9801 -0.9553 -0.9211 -0.8776 -0.8253 -0.7648 -0.6967 -0.6216 -0.5403 -0.4536 -0.3624 -0.2675 -0.1700 -0.0707 0.0292 0.1288 0.2272 0.3233 0.4161 0.5048 0.5885 0.6663 0.7374 0.8011 0.8569 0.9041 0.9422 0.9710
y = 1×63
-0.0000 -0.0998 -0.1987 -0.2955 -0.3894 -0.4794 -0.5646 -0.6442 -0.7174 -0.7833 -0.8415 -0.8912 -0.9320 -0.9636 -0.9854 -0.9975 -0.9996 -0.9917 -0.9738 -0.9463 -0.9093 -0.8632 -0.8085 -0.7457 -0.6755 -0.5985 -0.5155 -0.4274 -0.3350 -0.2392
function [x y] = unitCircle(theta)
z = [cos(theta);sin(theta)];
x = z(1,:);
y = z(2,:);
end
Doesn't work :-)
theta = (-pi:.1:pi).';
[x,y]=unitCircle(theta)
x = -1
y = -0.9950
function [x y] = unitCircle(theta)
z = [cos(theta);sin(theta)];
x = z(1,:);
y = z(2,:);
end

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More Answers (1)

Here is the corrected code:
% Ver 1
xy = unitCircle(pi/4)
xy = 2×1
0.7071 0.7071
function xy = unitCircle(theta)
xy=[cos(theta); sin(theta)];
end

1 Comment

Alt. version:
% Ver 2
theta = linspace(-2*pi, 2*pi);
xy=unitCircle(theta);
plot(xy(1,:), xy(2,:)), axis equal;
xlabel("x"), ylabel("y"), grid on
function xy = unitCircle(theta)
xy(1,:)=[cos(theta)];
xy(2,:)=[sin(theta)];
end

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Products

Release

R2022b

Asked:

on 12 Feb 2023

Edited:

on 12 Feb 2023

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