Friday, 15 November 2013

Awesome animation showing how a curve in the Cartesian plane can be mapped into polar coordinates:


Awesome animation showing how a curve in the Cartesian plane can be mapped into polar coordinates:
 y=sin(6x)+2 is mapped to r=sin(6theta)+2.

Gif via Reddit

8 comments:

  1. can you do that for any graph on the cartesian system?

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  2. Why is it mirrored first? One could just fold the x- instead of the y-axis.

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  3. Alexander N. Benner yes...same question in my mind too, as soon as I saw the complete sequence...

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  4. nevertheless, it is  superb animation...thanks for sharing :)

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  5. It's reflected through the line y=x to make the Cartesian coordinates match up with the polar coordinates. In Cartesian coordinates, x=0 in the middle of the graph and gets larger to the right. In polar coordinates, the angle (theta) starts at 0 on the right and gets larger as it rotates counter-clockwise.

    The reflection doesn't make too much of a difference to the shape of this particular graph because the function has odd symmetry (that is, f(-x) = -f(x)), but it would look "backwards" for more complicated functions.

    You can do this with any graph by replacing x with theta and y with r, but it's usually done only with trigonometric functions because they're cyclical. For example, if you converted the line y=x to r=theta, you'd get a spiral.

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  6. I like to watch the animation, thank you. What is it good for?

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  7. Uh oh, here we go again. Good one! :-)

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