plotting sinuos curve using matlab

Hello , i wrote the following code by the known formulla which is attached,but instead of getting the desired sinous shape ,i get a baloon, if any one could tell where did i go wrong . Thanks

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alpha=0.87
tau=1.35
r=1:0.01:1.35;
phi=alpha*sin((log(r)*pi)/(log(tau)));
figure;polarplot(r,phi);
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Answer 1

[Honglei Chen]

looks like it should be

polarplot(phi,r)

instead of

polarplot(r,phi)

HTH

[fima v]

Thank you very much