# multiple r values for multiple theta values

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Allan Asturias on 6 Mar 2021
Commented: Allan Asturias on 7 Mar 2021
theta=[pi,3,2.8,2.5,2,pi/2,1.3,1.0,0.75,0.5];
r=(pi-theta)/(sin(theta))
x=r*cos(theta)
y=r*sin(theta)
plot(x,y)
I was wondering how I can get it to give a different r value for each theta value. For example
theta=pi r=0 x=0 y=0
theta=3 r=1.0033 x=-0.9933 y=0.1416
theta=2.8 r=1.0197 x=-0.9608 y=0.3416
each theta value is used to get a differnt r value that is then used to get a different x and y point. Currently it only gives one r value and keeps using it for the differnt inputs. It should give a different r values for each theta value. Thank you.

David Goodmanson on 6 Mar 2021
Edited: David Goodmanson on 6 Mar 2021
Hi Allan
For an element-by-element calculation, use ./ and .* rather than / and *
theta=[pi,3,2.8,2.5,2,pi/2,1.3,1.0,0.75,0.5];
r=(pi-theta)./(sin(theta))
x=r.*cos(theta);
y=r.*sin(theta);
plot(x,y)
r =
0 1.0033 1.0197 1.0721 1.2555 1.5708 1.9112 2.5451 3.5086 5.5099
Allan Asturias on 7 Mar 2021
thank you very much!!