please help with this function

function [th rad]=cartopolar25(x,y

t=atan(y/x); rad=sqrt(x^2+y^2); if if x<0 if y<0 th=180+t return else th=180-t return end else if y<0 th=-t return else th=t return end end

end end

Hi I need help with this code, if you guys see any mistakes please let me know. I have to make a function to determine the polar coordinates from the Cartesian plane, thanks for the help yes I was able to get the degrees now all I need is the radians any tips with this current format thanks

Answer 1

[Narges M]

your function is this:

function [th rad]=cartopolar25(x,y)

th = atan(y/x);
rad = sqrt(x^2+y^2);

if x<0
    if y<0
        th=th+180;
    else
        th=th-180;
    end
else
    if y<0
        th=-th;
    end
end

and you need to call it like this:

[t,r] = cartopolar25(-11,20);

the output will be:

t =

      -181.0680

r =

     22.8254

[francis]

yes that was it I got it now

Answer 2

[Jonathan Sullivan]

help atan2
doc atan2

[francis]

whats that?

Answer 3

[Gorji]

What is Y and X? Are they matrix? I think the structure of 'if' is incorrect you must use if & elseif & else

[francis]

Y and X are supposed to be the coordinates, if I used that function with the points (-11,20) it should be able to give me radians=2.8 and deg=-118.8, I can do all of that on paper but here I am just trying to figure out I dont know how to defined Y and X, I try by using a vector and still gives me the same error "Undefined function or variable "y".

[francis]

I was able to get the degrees with a few changes yess, all I need some tips of putting the radiants on to this format, thanks

Answer 4

[Andrew Reibold]

atan doesn't take the 'y over x' value you seem to be thinking of. It takes an angle in radians....

Y = atan(X) returns the inverse tangent (arctangent) for each element of X. For real elements of X, atan(X) is in the range [–π/2, π/2].

The atan function operates element-wise on arrays. The function's domains and ranges include complex values. All angles are in radians.

Example Graph the inverse tangent function over the domain –20 ≤ x ≤ 20. x = -20:0.01:20; plot(x,atan(x)), grid on