Functions | |
| void | arm_sin_cos_f32 (float32_t theta, float32_t *pSinVal, float32_t *pCosVal) |
| void | arm_sin_cos_q31 (q31_t theta, q31_t *pSinVal, q31_t *pCosVal) |
Variables | |
| static const float32_t | cosTable [360] |
| static const float32_t | sinTable [360] |
| static const int32_t | sinTableQ31 [360] |
| static const int32_t | cosTableQ31 [360] |
Computes the trigonometric sine and cosine values using a combination of table lookup and linear interpolation. There are separate functions for Q31 and floating-point data types. The input to the floating-point version is in degrees while the fixed-point Q31 have a scaled input with the range [-1 1) mapping to [-180 180) degrees.
The implementation is based on table lookup using 360 values together with linear interpolation. The steps used are:
index from sine table to y0 and also value from index+1 to y1. *psinVal = y0 + (fract * (y1 - y0)).index from cosine table to y0 and also value from index+1 to y1. *pcosVal = y0 + (fract * (y1 - y0)). Floating-point sin_cos function.
| [in] | theta | input value in degrees |
| [out] | *pSinVal | points to the processed sine output. |
| [out] | *pCosVal | points to the processed cos output. |
Definition at line 367 of file arm_sin_cos_f32.c.
Q31 sin_cos function.
| [in] | theta | scaled input value in degrees |
| [out] | *pSinVal | points to the processed sine output. |
| [out] | *pCosVal | points to the processed cosine output. |
The Q31 input value is in the range [-1 +1) and is mapped to a degree value in the range [-180 180).
Definition at line 264 of file arm_sin_cos_q31.c.
for(i = 0; i < 360; i++)
{
cosTable[i]= cos((i-180) * PI/180.0);
} Definition at line 71 of file arm_sin_cos_f32.c.
for(i = 0; i < 360; i++)
{
sinTable[i]= sin((i-180) * PI/180.0);
} Definition at line 219 of file arm_sin_cos_f32.c.
const int32_t sinTableQ31[360] [static] |
for(i = 0; i < 360; i++)
{
sinTable[i]= sin((i-180) * PI/180.0);
} Convert above coefficients to fixed point 1.31 format. Definition at line 51 of file arm_sin_cos_q31.c.
const int32_t cosTableQ31[360] [static] |
for(i = 0; i < 360; i++)
{
cosTable[i]= cos((i-180) * PI/180.0);
} Definition at line 157 of file arm_sin_cos_q31.c.
1.7.2