CMSIS2000
0.0.7
|
Computes the square root of a number. Подробнее...
Функции | |
__STATIC_INLINE arm_status | arm_sqrt_f32 (float32_t in, float32_t *pOut) |
Floating-point square root function. | |
arm_status | arm_sqrt_q15 (q15_t in, q15_t *pOut) |
Q15 square root function. | |
arm_status | arm_sqrt_q31 (q31_t in, q31_t *pOut) |
Q31 square root function. |
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]
__STATIC_INLINE arm_status arm_sqrt_f32 | ( | float32_t | in, |
float32_t * | pOut | ||
) |
Floating-point square root function.
[in] | in | input value. |
[out] | *pOut | square root of input value. |
in
is negative value and returns zero output for negative values. См. определение в файле arm_math.h строка 6195
Перекрестные ссылки ARM_MATH_ARGUMENT_ERROR и ARM_MATH_SUCCESS.
arm_status arm_sqrt_q15 | ( | q15_t | in, |
q15_t * | pOut | ||
) |
Q15 square root function.
[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. arm_status arm_sqrt_q31 | ( | q31_t | in, |
q31_t * | pOut | ||
) |
Q31 square root function.
[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.