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CMSIS-DSP
Version 1.5.2
CMSIS DSP Software Library
|
Functions | |
| CMSIS_INLINE __STATIC_INLINE arm_status | arm_sqrt_f32 (float32_t in, float32_t *pOut) |
| Floating-point square root function. More... | |
| arm_status | arm_sqrt_q31 (q31_t in, q31_t *pOut) |
| Q31 square root function. More... | |
| arm_status | arm_sqrt_q15 (q15_t in, q15_t *pOut) |
| Q15 square root function. More... | |
Computes the square root of a number. There are separate functions for Q15, Q31, and floating-point data types. The square root function is computed using the Newton-Raphson algorithm. This is an iterative algorithm of the form:
x1 = x0 - f(x0)/f'(x0)
where x1 is the current estimate, x0 is the previous estimate, and f'(x0) is the derivative of f() evaluated at x0. For the square root function, the algorithm reduces to:
x0 = in/2 [initial guess]
x1 = 1/2 * ( x0 + in / x0) [each iteration]
| CMSIS_INLINE __STATIC_INLINE arm_status arm_sqrt_f32 | ( | float32_t | in, |
| float32_t * | pOut | ||
| ) |
| [in] | in | input value. |
| [out] | pOut | square root of input value. |
in is negative value and returns zero output for negative values. References ARM_MATH_ARGUMENT_ERROR, and ARM_MATH_SUCCESS.
Referenced by arm_cmplx_mag_f32(), arm_rms_f32(), and arm_std_f32().
| arm_status arm_sqrt_q15 | ( | q15_t | in, |
| q15_t * | pOut | ||
| ) |
| [in] | in | input value. The range of the input value is [0 +1) or 0x0000 to 0x7FFF. |
| [out] | pOut | square root of input value. |
in is negative value and returns zero output for negative values.| [in] | in | input value. The range of the input value is [0 +1) or 0x0000 to 0x7FFF. |
| [out] | *pOut | square root of input value. |
References ARM_MATH_ARGUMENT_ERROR, and ARM_MATH_SUCCESS.
Referenced by arm_cmplx_mag_q15(), arm_rms_q15(), and arm_std_q15().
| arm_status arm_sqrt_q31 | ( | q31_t | in, |
| q31_t * | pOut | ||
| ) |
| [in] | in | input value. The range of the input value is [0 +1) or 0x00000000 to 0x7FFFFFFF. |
| [out] | pOut | square root of input value. |
in is negative value and returns zero output for negative values.| [in] | in | input value. The range of the input value is [0 +1) or 0x00000000 to 0x7FFFFFFF. |
| [out] | *pOut | square root of input value. |
References ARM_MATH_ARGUMENT_ERROR, and ARM_MATH_SUCCESS.
Referenced by arm_cmplx_mag_q31(), arm_rms_q31(), and arm_std_q31().