## Developer Reference

• 2020.2
• 07/15/2020
• Public Content
Contents

# ?sytrs_aa

Solves a system of linear equations A * X = B with a symmetric matrix.
Description
?sytrs_aa
solves a system of linear equations A * X = B with a symmetric matrix A using the factorization A = U*T*U
T
or A = L*T*L
T
computed by
?sytrf_aa
.
Input Parameters
uplo
CHARACTER*1
Specifies whether the details of the factorization are stored as an upper or lower triangular matrix.
• =
'U'
: Upper triangular; the form is A = U*T*U
T
.
• =
'L'
: Lower triangular; the form is A = L*T*L
T
.
n
INTEGER
The order of the matrix A.
n
≥ 0.
nrhs
INTEGER
The number of right-hand sides; that is, the number of columns of the matrix B.
nrhs
≥ 0.
A
REAL
for
ssytrs_aa
DOUBLE COMPLEX
for
dsytrs_aa
COMPLEX
for
csytrs_aa
COMPLEX*16
for
zsytrs_aa
Array, dimension (
lda
,
n
).
Details of factors computed by
?sytrf_aa
.
lda
INTEGER
The leading dimension of the array
A
.
lda
≥ max(1,
n
).
ipiv
INTEGER
Array, dimension (
n
).
Details of the interchanges as computed by
?sytrf_aa
.
B
REAL
for
ssytrs_aa
DOUBLE COMPLEX
for
dsytrs_aa
COMPLEX
for
csytrs_aa
COMPLEX*16
for
zsytrs_aa
Array, dimension (
ldb
,
nrhs
).
On entry, the right-hand side matrix B.
ldb
INTEGER
The leading dimension of the array
B
.
ldb
≥ max(1,
n
).
work
Array, dimension (MAX(1,
lwork
)).
REAL
for
ssytrs_aa
DOUBLE COMPLEX
for
dsytrs_aa
COMPLEX
for
csytrs_aa
COMPLEX*16
for
zsytrs_aa
lwork
INTEGER
The length of the array
work
.
Output Parameters
B
REAL
for
ssytrs_aa