six pointed star

I need to know how to plot a six pointed star using polar coordinates. I know I need to use the hold on/hold off funcion but I'm not really sure what else?

Answer 1

[Jan]

No, you do not need hold. You can modify the example you find in help polar.

Answer 2

[T]

I worked on this same problem for a while until I just figured it out.. Talk about a PAIN! There may be a better way of doing it but this worked for me:

theta = [pi/6:(2/3)*pi:4*pi] r= ones(1,6) polar(theta,r) hold on theta = [pi/6:(2/3)*pi:4*pi] r= ones(1,6) polar(-theta,r)

Answer 3

[Voss]

th = 0:30:360;
r = [1/sqrt(3) 1];
r = r(1+mod(1:numel(th),2));

plot(r.*cosd(th),r.*sind(th))
axis square

Answer 4

[Thomas Wellington]

I worte a function that returns the coordinates of a six coordinates of a six pointed star. (See the code below.) You can call this function and then plot the coordinates (e.g. [x,y] = Six_Pointed_Star(2), press enter and type plot(x,y) on the next line.

Hope this helps. Any comments are welcome especially because I am a MATLAB newbie.

• Tom

function [xcoords, ycoords] = Six_Pointed_Star(side_length)

%returns the x and y coordinates of a six pointed star

%whose sides are of length side length

xcoords = zeros(1,13);

ycoords = zeros(1,13);

if (~ isa(side_length, 'double')) || side_length <= 0

disp('Function argument is invalid type or less than zero.')

disp('Try again') %checks for invalid input

else %get coordinates

j = 0;

for degrees = 0:30:360

radians = degrees*pi/180;

j = j + 1;

if rem(degrees,60) == 0

xcoords(j) = side_length * cos(radians);

ycoords(j) = side_length * sin(radians);

else

xcoords(j) = sqrt(3) * side_length * cos(radians);

ycoords(j) = sqrt(3) * side_length * sin(radians);

end % of inner if

end % of for loop

end % of outer if

end % of function