how to retrieve location from accelerometer and magnetometer in android

Question

I want to retrieve the location and speed from accelerometer and magnetometer in the android device, I can currently get the speed from accelerometer, but how do I correlate it with the location from the magnetometer sensor, using both speed sensor and the geomagnetic field?

Answer 1

This question comes up surprisingly often.

You cannot get accurate location or even velocity, but here are tips what you actually could do instead.