Embedded Software and Motor Control Libraries for PXR40xx

Function GFLIB_AtanYXShifted_F32
In the second step, the vector ordinate is divided by the vector abscissa (y/x) to obtain the
tangent value of the angle offset. The angle offset is computed by applying the ordinary
arctangent function.
The sum of the angle addition and the angle offset within a single quarter form the angle
to be computed. The function will return 0 if both input arguments are 0.
Note
The function calls the GFLIB_Atan_FLT function. The
computed value is within the range of [- π, π].
4.36.5 Re-entrancy
The function is re-entrant.
4.36.6 Code Example
#include "gflib.h"
tFloat fltInY;
tFloat fltInX;
tFloat fltAng;
void main(void)
{
// Angle 45 deg = PI/4 rad
fltInY = (tFloat)(0.5);
fltInX = (tFloat)(0.5);
}
// Output angle should be 45 deg = PI/4 rad = 0.7853981634
fltAng = GFLIB_AtanYX_FLT (fltInY, fltInX);
// Output angle should be 45 deg = PI/4 rad = 0.7853981634
fltAng = GFLIB_AtanYX (fltInY, fltInX, Define FLT);
// ##############################################################
// Available only if single precision floating point
// implementation selected as default
// ##############################################################
// Output angle should be 45 deg = PI/4 rad = 0.7853981634
fltAng = GFLIB_AtanYX (fltInY, fltInX);
4.37 Function GFLIB_AtanYXShifted_F32
This function calculates the angle of two sine waves shifted in phase to each other.
Embedded Software and Motor Control Libraries for PXR40xx, Rev. 1.0
252 Freescale Semiconductor, Inc.