Apply an array to an equations variable?

I have an equation say theta2 = 100 * cosd(theta1). I want to set theta1 = [0:1:360], then have an array output for theta2, then somehow graph the theta2 result over the degree interval of 0 to 360. I am unsure how to do this as when I set theta1 this way it just gives me a constant value for theta2. So how would I apply this array and how would I graph the results for the period? Thanks for any help!

2 Comments

Are you sure you are entering this correctly? When I do
theta1 = 0:1:360;
theta2 = 100 * cosd(theta1)
I get a 1x361 double array of calling cosd on each element of theta1
Well my equation is thetad = atand((r1*sind(theta1)+E)/(r1*cosd(theta1)-rO))+180; where r1,E,and rO are knowns. It gives me a constant as a result. Not the array like I am seeking.

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Answers (1)

Make sure your multiplications are element-wise (and your divisions) by including the dot before your product sign and your division sign. Compare the differences between the calculations below.
a=rand(1,3);
b=rand(1,3);
a*(b')
a.*(b') %equivalent to [a;a;a].*[(b') (b') (b')] (or with |bsxfun|)
a.*b

1 Comment

Rik
Rik on 30 Jun 2018
Edited: Rik on 2 Jul 2018
Did my answer solve your problem (i.e. thetad = atand((r1.*sind(theta1)+E)./(r1.*cosd(theta1)-rO))+180)? If so, please consider marking it as accepted answer. It will make it easier for other people with the same question to find an answer. If this didn't solve your question, please comment with what problems you are still having.

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R2017b

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Asked:

on 27 Jun 2018

Edited:

Rik
on 2 Jul 2018

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