How do I fit my data to a cos^2?

Hi, I have collected this data of angle and Intensity to show that Malus law works

theta = [90, 110, 130, 135, 150, 170, 180, 190, 210, 225, 230, 250, 270, 290, 310,315,330, 350, 365, 370, 390]

I= [0.0030, 0.6240, 1.3060, 1.3320, 0.9610, 0.1900, 0.0160, 0.1970, 1.1250, 1.3480, 1.2900, 0.5660, 0.0030, 0.5750, 1.6170, 1.6760, 1.0850, 0.1380, 0.0940, 0.2250, 1.2340]

I tried a few ways but when it comes to plotting I obtain very strange stuff like lines far from the points and I think I just didn't understand how you do this. Thank you very much in advance for your help!

Answer 1

[Kevin Phung]

All I used was the plot function and I got something pretty sinusoidal

theta = [90, 110, 130, 135, 150, 170, 180, 190, 210, 225, 230, 250, 270, 290, 310,315,330, 350, 365,  370, 390]
I=  [0.0030, 0.6240, 1.3060, 1.3320, 0.9610, 0.1900, 0.0160, 0.1970, 1.1250, 1.3480, 1.2900, 0.5660, 0.0030, 0.5750,...
    1.6170, 1.6760, 1.0850, 0.1380, 0.0940,  0.2250, 1.2340]
figure
plot(theta,I)

does this not work for you?