Matrix Scale

Functions
arm_status	arm_mat_scale_f32 (const arm_matrix_instance_f32 *pSrc, float32_t scale, arm_matrix_instance_f32 *pDst)
	Floating-point matrix scaling.
arm_status	arm_mat_scale_q15 (const arm_matrix_instance_q15 *pSrc, q15_t scaleFract, int32_t shift, arm_matrix_instance_q15 *pDst)
	Q15 matrix scaling.
arm_status	arm_mat_scale_q31 (const arm_matrix_instance_q31 *pSrc, q31_t scaleFract, int32_t shift, arm_matrix_instance_q31 *pDst)
	Q31 matrix scaling.

Description

Multiplies a matrix by a scalar. This is accomplished by multiplying each element in the matrix by the scalar. For example:

Matrix Scaling of a 3 x 3 matrix

The function checks to make sure that the input and output matrices are of the same size.

In the fixed-point Q15 and Q31 functions, scale is represented by a fractional multiplication scaleFract and an arithmetic shift shift. The shift allows the gain of the scaling operation to exceed 1.0. The overall scale factor applied to the fixed-point data is

        
    scale = scaleFract * 2^shift.        

Function Documentation

arm_status arm_mat_scale_f32	(	const arm_matrix_instance_f32 *	pSrc,
		float32_t	scale,
		arm_matrix_instance_f32 *	pDst
	)

Parameters

[in]	*pSrc	points to input matrix structure
[in]	scale	scale factor to be applied
[out]	*pDst	points to output matrix structure

Returns

The function returns either ARM_MATH_SIZE_MISMATCH or ARM_MATH_SUCCESS based on the outcome of size checking.

References ARM_MATH_SIZE_MISMATCH, ARM_MATH_SUCCESS, arm_matrix_instance_f32::numCols, arm_matrix_instance_f32::numRows, arm_matrix_instance_f32::pData, and status.

arm_status arm_mat_scale_q15	(	const arm_matrix_instance_q15 *	pSrc,
		q15_t	scaleFract,
		int32_t	shift,
		arm_matrix_instance_q15 *	pDst
	)

Parameters

[in]	*pSrc	points to input matrix
[in]	scaleFract	fractional portion of the scale factor
[in]	shift	number of bits to shift the result by
[out]	*pDst	points to output matrix structure

Returns

The function returns either ARM_MATH_SIZE_MISMATCH or ARM_MATH_SUCCESS based on the outcome of size checking.

Scaling and Overflow Behavior:

The input data *pSrc and scaleFract are in 1.15 format. These are multiplied to yield a 2.30 intermediate result and this is shifted with saturation to 1.15 format.

References _SIMD32_OFFSET, ARM_MATH_SIZE_MISMATCH, ARM_MATH_SUCCESS, arm_matrix_instance_q15::numCols, arm_matrix_instance_q15::numRows, arm_matrix_instance_q15::pData, and status.

arm_status arm_mat_scale_q31	(	const arm_matrix_instance_q31 *	pSrc,
		q31_t	scaleFract,
		int32_t	shift,
		arm_matrix_instance_q31 *	pDst
	)

Parameters

[in]	*pSrc	points to input matrix
[in]	scaleFract	fractional portion of the scale factor
[in]	shift	number of bits to shift the result by
[out]	*pDst	points to output matrix structure

Returns

The function returns either ARM_MATH_SIZE_MISMATCH or ARM_MATH_SUCCESS based on the outcome of size checking.

Scaling and Overflow Behavior:

The input data *pSrc and scaleFract are in 1.31 format. These are multiplied to yield a 2.62 intermediate result and this is shifted with saturation to 1.31 format.

References ARM_MATH_SIZE_MISMATCH, ARM_MATH_SUCCESS, arm_matrix_instance_q31::numCols, arm_matrix_instance_q31::numRows, arm_matrix_instance_q31::pData, and status.