Functions
arm_status	arm_mat_inverse_f16 (const arm_matrix_instance_f16 pSrc, arm_matrix_instance_f16 pDst)
	Floating-point matrix inverse. More...

arm_status	arm_mat_inverse_f32 (const arm_matrix_instance_f32 pSrc, arm_matrix_instance_f32 pDst)
	Floating-point matrix inverse. More...

arm_status	arm_mat_inverse_f64 (const arm_matrix_instance_f64 pSrc, arm_matrix_instance_f64 pDst)
	Floating-point (64 bit) matrix inverse. More...

arm_status	arm_mat_solve_lower_triangular_f16 (const arm_matrix_instance_f16 lt, const arm_matrix_instance_f16 a, arm_matrix_instance_f16 *dst)
	Solve LT . X = A where LT is a lower triangular matrix. More...

arm_status	arm_mat_solve_lower_triangular_f32 (const arm_matrix_instance_f32 lt, const arm_matrix_instance_f32 a, arm_matrix_instance_f32 *dst)
	Solve LT . X = A where LT is a lower triangular matrix. More...

arm_status	arm_mat_solve_lower_triangular_f64 (const arm_matrix_instance_f64 lt, const arm_matrix_instance_f64 a, arm_matrix_instance_f64 *dst)
	Solve LT . X = A where LT is a lower triangular matrix. More...

arm_status	arm_mat_solve_upper_triangular_f16 (const arm_matrix_instance_f16 ut, const arm_matrix_instance_f16 a, arm_matrix_instance_f16 *dst)
	Solve UT . X = A where UT is an upper triangular matrix. More...

arm_status	arm_mat_solve_upper_triangular_f32 (const arm_matrix_instance_f32 ut, const arm_matrix_instance_f32 a, arm_matrix_instance_f32 *dst)
	Solve UT . X = A where UT is an upper triangular matrix. More...

arm_status	arm_mat_solve_upper_triangular_f64 (const arm_matrix_instance_f64 ut, const arm_matrix_instance_f64 a, arm_matrix_instance_f64 *dst)
	Solve UT . X = A where UT is an upper triangular matrix. More...

Description

Computes the inverse of a matrix.

The inverse is defined only if the input matrix is square and non-singular (the determinant is non-zero). The function checks that the input and output matrices are square and of the same size.

Matrix inversion is numerically sensitive and the CMSIS DSP library only supports matrix inversion of floating-point matrices.

Algorithm: The Gauss-Jordan method is used to find the inverse. The algorithm performs a sequence of elementary row-operations until it reduces the input matrix to an identity matrix. Applying the same sequence of elementary row-operations to an identity matrix yields the inverse matrix. If the input matrix is singular, then the algorithm terminates and returns error status ARM_MATH_SINGULAR.

Matrix Inverse of a 3 x 3 matrix using Gauss-Jordan Method

Function Documentation

arm_status arm_mat_inverse_f16	(	const arm_matrix_instance_f16 *	pSrc,
		arm_matrix_instance_f16 *	pDst
	)

Parameters

[in]	pSrc	points to input matrix structure. The source matrix is modified by the function.
[out]	pDst	points to output matrix structure

Returns

execution status

ARM_MATH_SUCCESS : Operation successful
ARM_MATH_SIZE_MISMATCH : Matrix size check failed
ARM_MATH_SINGULAR : Input matrix is found to be singular (non-invertible)

arm_status arm_mat_inverse_f32	(	const arm_matrix_instance_f32 *	pSrc,
		arm_matrix_instance_f32 *	pDst
	)

Parameters

[in]	pSrc	points to input matrix structure. The source matrix is modified by the function.
[out]	pDst	points to output matrix structure

Returns

execution status

ARM_MATH_SUCCESS : Operation successful
ARM_MATH_SIZE_MISMATCH : Matrix size check failed
ARM_MATH_SINGULAR : Input matrix is found to be singular (non-invertible)

arm_status arm_mat_inverse_f64	(	const arm_matrix_instance_f64 *	pSrc,
		arm_matrix_instance_f64 *	pDst
	)

Floating-point matrix inverse.

Parameters

[in]	pSrc	points to input matrix structure. The source matrix is modified by the function.
[out]	pDst	points to output matrix structure

Returns

execution status

ARM_MATH_SUCCESS : Operation successful
ARM_MATH_SIZE_MISMATCH : Matrix size check failed
ARM_MATH_SINGULAR : Input matrix is found to be singular (non-invertible)

arm_status arm_mat_solve_lower_triangular_f16	(	const arm_matrix_instance_f16 *	lt,
		const arm_matrix_instance_f16 *	a,
		arm_matrix_instance_f16 *	dst
	)

Parameters

[in]	lt	The lower triangular matrix
[in]	a	The matrix a
[out]	dst	The solution X of LT . X = A

Returns: The function returns ARM_MATH_SINGULAR, if the system can't be solved.

arm_status arm_mat_solve_lower_triangular_f32	(	const arm_matrix_instance_f32 *	lt,
		const arm_matrix_instance_f32 *	a,
		arm_matrix_instance_f32 *	dst
	)

Parameters

[in]	lt	The lower triangular matrix
[in]	a	The matrix a
[out]	dst	The solution X of LT . X = A

Returns: The function returns ARM_MATH_SINGULAR, if the system can't be solved.

arm_status arm_mat_solve_lower_triangular_f64	(	const arm_matrix_instance_f64 *	lt,
		const arm_matrix_instance_f64 *	a,
		arm_matrix_instance_f64 *	dst
	)

Parameters

[in]	lt	The lower triangular matrix
[in]	a	The matrix a
[out]	dst	The solution X of LT . X = A

Returns: The function returns ARM_MATH_SINGULAR, if the system can't be solved.

arm_status arm_mat_solve_upper_triangular_f16	(	const arm_matrix_instance_f16 *	ut,
		const arm_matrix_instance_f16 *	a,
		arm_matrix_instance_f16 *	dst
	)

Parameters

[in]	ut	The upper triangular matrix
[in]	a	The matrix a
[out]	dst	The solution X of UT . X = A

Returns: The function returns ARM_MATH_SINGULAR, if the system can't be solved.

arm_status arm_mat_solve_upper_triangular_f32	(	const arm_matrix_instance_f32 *	ut,
		const arm_matrix_instance_f32 *	a,
		arm_matrix_instance_f32 *	dst
	)

Parameters

[in]	ut	The upper triangular matrix
[in]	a	The matrix a
[out]	dst	The solution X of UT . X = A

Returns: The function returns ARM_MATH_SINGULAR, if the system can't be solved.

arm_status arm_mat_solve_upper_triangular_f64	(	const arm_matrix_instance_f64 *	ut,
		const arm_matrix_instance_f64 *	a,
		arm_matrix_instance_f64 *	dst
	)

Parameters

[in]	ut	The upper triangular matrix
[in]	a	The matrix a
[out]	dst	The solution X of UT . X = A

Returns: The function returns ARM_MATH_SINGULAR, if the system can't be solved.

Functions

Description

Function Documentation