symbol correction

[gooyle]

[gooyle]

thx for your package！！！it helps a lot,i think here are some mistakes, i use xsens data to test. in file:

ahrs/ahrs/filters/mahony.py

#Rotate magnetic field to inertial frame ~~v_m = [email protected]([-np.linalg.norm([h[0], h[1]]) , 0.0, h[2]])~~ ##no minus v_m = [email protected]([np.linalg.norm([h[0], h[1]]) , 0.0, h[2]]) and here is the results，shown in roll、pitch and yaw：

• and here is the results about m and v_m:

[Mayitzin]

This was adressed already in the commit 34f959f96adba5064d1e4f0142eaad971f7f3c64, and there was a major change with it too.

The creation of the v_m was, apparently, not correct. Please, test the new version, if possible, and let me know if you see any improvements at all.