Distance between two points in polar coordinate system.

[sotnet]

Guys,

Any ideas on how to calculate distance between two points in Polar coordinate system without converting their coordinates to Cartesian?

Ps. I know that if I converted from Polar (r, t) to Cartesian (x, y) by x = r.cos(t), y = r.sin(t), then the distance between two points would be d = sqrt((x1 - x2)^2 + (y1 - y2)^2).Thanks,
Steve

 

[lzkelley]

You use the law of cosines.
Construct a triangle with vertices at the origin, and the two points.
Its a cool trick, but makes for a huge pain in the ass for calculating inverse square laws etc. in polar/spherical.

I can elaborate if the setup doesn't make sense.