6.4.1 vsip_dchold_create_p - Create Cholesky Decomposition Object

typedef enum _vsip_mat_uplo { 
  VSIP_TR_LOW = 0, // Lower triangular 
  VSIP_TR_UPP = 1  // Upper triangular 
} vsip_mat_uplo; 
 
vsip_chol_f* vsip_chold_create_f(vsip_mat_uplo uplo, vsip_length n); 
vsip_cchol_f* vsip_cchold_create_f(vsip_mat_uplo uplo, vsip_length n);

Description

This function creates a Cholesky decomposition object for a symmetric positive definite matrix of size . The Cholesky decomposition expresses a matrix as the product of a lower triangular matrix and its transpose: (when uplo = VSIP_MAT_LOWER) or (when uplo = VSIP_MAT_UPPER).

Parameters

• vsip_mat_uplo uplo: Specifies whether to store the upper (VSIP_MAT_UPP) or lower (VSIP_MAT_LOW) triangle of the matrix.

• vsip_length n: The dimension of the square matrix ().

Return Value

• On success: Pointer to the newly created Cholesky decomposition object

• On error (e.g., memory allocation failure): NULL

Example

vsip_chol_f *chold; 
vsip_length n = 100; 
 
// Create Cholesky decomposition object for lower triangle 
chold = vsip_chold_create_f(VSIP_MAT_LOW, n); 
if (chold == NULL) { 
    fprintf(stderr, "Error: Could not create Cholesky object\n"); 
    return -1; 
}

Notes

• The matrix must be symmetric and positive definite, otherwise the decomposition will fail.

• The object should be freed with vsip_dchold_destroy_p when no longer needed.