6.3.5 vsip_dlusol_p - Solve Linear System Using LU Decomposition

int vsip_lusol_f(const vsip_lu_f* lud, const vsip_vview_f* b, const vsip_vview_f* x); 
int vsip_clusol_f(const vsip_clu_f* lud, const vsip_cvview_f* b, const vsip_cvview_f* x);

Description

This function solves a system a linear square system int the forms of:

Where the matrix has previously been decomposed using the function vsip_dlud_p . Whether the matrix A is transposed depends on the given argument provided.

Parameters

• const vsip_dlu_f* lud: Pointer to the LU decomposition object containing the decomposed factors of matrix .

• vsip_mat_op OpA: Operand for the input matrix .

  • VSIP_MAT_NTRANS - Do not transpose.

  • VSIP_MAT_TRANS - Transpose.

  • VSIP_MAT_HERM - Hermitian (Complex only).

• const vsip_dmview_f* xb: Pointer to the right-hand side matrix of order by . On exit result matrix .

Return Value

• Returns 0 on success.

• Returns a non-zero value on error (e.g., if dimensions are incompatible or the matrix is singular).

Example

vsip_lu_f *lu_obj; 
vsip_mview_f *a, *xb; 
 
// Assuming all objects have been properly initialized 
// First perform LU decomposition 
result = vsip_lud_f(lu_obj, a); 
if (result != 0) { 
    // Handle decomposition error 
} 
 
// Then solve the linear system 
result = vsip_lusol_f(lu_obj, VSIP_MAT_NTRANS, xb); 
if (result != 0) { 
    // Handle solve error 
}

Notes

• The LU decomposition object must have been previously created and used to decompose a matrix.