q15_atan.h

Texas-Instrument C2000 Series DSP example programs

/*--------------------------------------------------------------------
  int q15_atan(int);
 ---------------------------------------------------------------------
  Function:     arcus tanges, for signed fractional q15 format
                                                                
  Arguments:    signed fractional q15
                min: -1.0   <--> 8000h 
                max: 0.9999 <--> 7FFFh
                                                                
  Return value: scaled angle (-PI/4 .. PI/4)
                scaling: PI  (e.g. atan(1.0) = 0.25 or 2000h)

  Error:         < 2 LSB  (128 point lookup table)
 -------------------------------------------------------------------*/

#ifndef  __Q15_ATAN_H_
#define  __Q15_ATAN_H_

int      q15_atan(int value);
unsigned q15p_atan(unsigned value);	/* dito, but only positive q15 */

#endif