(input/output) REAL or COMPLEX
array, shape with
, where is the number of superdiagonals
or subdiagonals in the band and is the order of .
On entry, the upper (if UPLO = 'U') or lower
(if UPLO = 'L') triangle of matrix in band storage.
The diagonals of are stored in the rows of AB
so that the column of is
stored in the column of as follows:
On exit, the factor or from
the Cholesky factorization
in the same storage format as .