Eli Hughes / CMSIS_DSP_401

V4.0.1 of the ARM CMSIS DSP libraries. Note that arm_bitreversal2.s, arm_cfft_f32.c and arm_rfft_fast_f32.c had to be removed. arm_bitreversal2.s will not assemble with the online tools. So, the fast f32 FFT functions are not yet available. All the other FFT functions are available.

Dependents:   MPU9150_Example fir_f32 fir_f32 MPU9150_nucleo_noni2cdev ... more

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Matrix Scale
Functions

Matrix Scale
[Matrix Functions]

Multiplies a matrix by a scalar. More...

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.

Detailed 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 
)

Floating-point matrix scaling.

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.

Definition at line 80 of file arm_mat_scale_f32.c.

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.

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.

Definition at line 68 of file arm_mat_scale_q15.c.

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.

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.

Definition at line 67 of file arm_mat_scale_q31.c.

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