Matrix ScaleMatrix Functions

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:

MatrixScale.gif
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]*pSrcpoints to input matrix structure
[in]scalescale factor to be applied
[out]*pDstpoints 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]*pSrcpoints to input matrix
[in]scaleFractfractional portion of the scale factor
[in]shiftnumber of bits to shift the result by
[out]*pDstpoints 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 __PKHBT, _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]*pSrcpoints to input matrix
[in]scaleFractfractional portion of the scale factor
[in]shiftnumber of bits to shift the result by
[out]*pDstpoints 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.