设为首页
加入收藏
期刊导航
网站地图
首页
期刊
数学与物理
地球与环境
信息通讯
经济与管理
生命科学
工程技术
医药卫生
人文社科
化学与材料
会议
合作
新闻
我们
招聘
千人智库
我要投稿
办刊
期刊菜单
●领域
●编委
●投稿须知
●最新文章
●检索
●投稿
文章导航
●Abstract
●Full-Text PDF
●Full-Text HTML
●Full-Text ePUB
●Linked References
●How to Cite this Article
PureMathematics
n
Ø
ê
Æ
,2023,13(6),1677-1688
PublishedOnlineJune2023inHans.https://www.hanspub.org/journal/pm
https://doi.org/10.12677/pm.2023.136171
E
‚
5
X
Ú
•
Ø
444
ŒŒŒ
Ü
“
‰
Œ
Æ
ê
Æ
†
Ú
O
Æ
§
[
‹
=
²
Â
v
F
Ï
µ
2023
c
5
19
F
¶
¹
^
F
Ï
µ
2023
c
6
20
F
¶
u
Ù
F
Ï
µ
2023
c
6
28
F
Á
‡
©
ï
Ä
E
ê
•
þ
˜
a
2
Â
Q
:
X
Ú
(
z
•
Ø
§
¿
ò
Ù
¥
ü
«
A
Ï
œ
¹
§
í
Ñ
•
Ø
O
Ž
ú
ª
"
Ï
L
ê
Š
~
f
L
²
§
·
‚
(
J
Œ
±
•
B
/
u
¢
S
Ž
{
-
½
5
§
í
Ñ
#
(
z
•
Ø
'
~
^
•
•
Ü
·
Ú
k
"
'
…
c
•
Ø
§
E
ê
•
§
r
-
½
BackwardErrorofComplex
LinearSystem
YulingLiu
CollegeofMathematicsandStatistics,NorthwestNormalUniversity,LanzhouGansu
Received:May19
th
,2023;accepted:Jun.20
th
,2023;published:Jun.28
th
,2023
Abstract
Inthispaper,thestructuredbackwarderrorofaclassofgeneralizedsaddle-point
systemsincomplexnumberfieldisstudied,andtwospecialcasesareextended,and
thecalculationformulaofbackwarderrorisderived.Numericalexamplesshowthat
our results caneasily test the stability of the actual algorithm, and thenew structured
backwarderrorismoresuitableandeffectivethanthecommonone.
©
Ù
Ú
^
:
4
Œ
.
E
‚
5
X
Ú
•
Ø
[J].
n
Ø
ê
Æ
,2023,13(6):1677-1688.
DOI:10.12677/pm.2023.136171
4
Œ
Keywords
BackwardError,ComplexNumberField,StrongStability
Copyright
c
2023byauthor(s)andHansPublishersInc.
This work is licensed undertheCreative Commons Attribution International License (CCBY 4.0).
http://creativecommons.org/licenses/by/4.0/
1.
Ú
ó
•
Ä
E
ê
•
þ
2
@
2
¬
‚
5
X
Ú
H
z
=
d
(
z
•
Ø
©
Û
,
Ù
¥
H
=
A
+
iB
,
z
=
x
+
iy
,
d
=
u
+
iv
.
Ù
¥
A,B
´
n
×
n
¢
Ý
,
x,y,f,g
´
n
×
1
¢
•
þ
,
i
=
√
−
1
´
J
ê
ü
.
H
z
=
d
Œ
±
L
«
•
H
z
=
"
A
−
B
BA
#"
x
y
#
=
"
u
v
#
=
d,
(1.1)
A
•
E
é
¡
Ý
,(1.1)
ù
‡
X
Ú
¡
•
2
Â
Q
:
X
Ú
§
·
‚
•
Ä
x
6
=0
,y
6
=0
…
A
6
=
A
>
,B
6
=
B
>
ž
(
z
•
Ø
,
¿
•
Ä
x
=0
½
y
=0
ž
±
e
(
µ
(i)
A
6
=
A
>
,B
6
=
B
>
;(ii)
A
=
A
>
,B
=
B
>
;(iii)
B
=
B
>
;(iv)
A
=
A
>
.
•
Ø
3
ê
Š
©
Û
¥
š
~
-
‡
,
§
Œ
±
£
‰
¢
S
)û
¯
K
†
·
‚
Ž
‡
)û
¯
K
k
õ
C
,
¿
«
ê
Š
•{
-
½
5
.
C
c
5
,
N
õ
Š
ö
é
¢
ê
•
þ
2
Â
Q
:
¯
K
(
z
•
Ø
u
Ð
Š
Ñ
z
,
ù
a
¯
K
3
N
õ
‰
Æ
Ú
ó
§
+
•
¥
Ñ
k
é
-
‡
A^
[1–7].
©
3
c
<
Ä
:
þ
,
?
1
O
Ž
E
ê
•
þ
2
Â
Q
:
¯
K
(
z
•
Ø
.
b
e
z
=(
e
x
>
,
e
y
>
)
>
´
‚
5
X
Ú
(1.1)
O
Ž
)
,
du
6
Ä
∆
H
Ú
∆
d
¦
e
z
¤
•
6
Ä
‚
5
X
Ú
H
+∆
H
=
d
+∆
d
O
(
)
.
•
ÿ
þ
6
Ä
X
Ú
Ú
©
X
Ú
ƒ
m
•
Cå
l
,
•
Ø
n
Ø
u
y
¿
…
2
•
A^
[8],
§
Œ
±
^
5
ÿ
Á
Ž
{
-
½
5
.
3
©
¥
,
é
u
š
(
z
‚
5
X
Ú
(1.1),
•
Ø
½
Â
•
η
(
e
z
) =min
∆
H
,
∆
d
(
k
∆
Hk
F
kHk
F
,
k
∆
d
k
2
k
d
k
2
)
2
.
½
η
(
e
z
) =
kH
e
z
−
d
k
2
p
kHk
2
F
k
e
z
k
2
2
+
k
d
k
2
2
,
Ù
¥
k
.
k
F
,
k
.
k
2
©
OL
«
F
−
‰
ê
,2
−
‰
ê
.
X
J
η
(
e
z
)
é
,
·
‚
Ò
`Ž
{
´
•
-
½
.
,
,
Š
5
¿
´
,
X
J
X
ê
Ý
H
k
A
Ï
(
,
6
Ä
X
ê
Ý
H
+∆
H
•
¬
±
Ó
(
.
Ï
d
,
·
‚
I
‡
O
Ž
(
z
•
Ø
.
é
u
(
z
•
Ø
,
c
<
®
²
‰
Œ
þ
ï
Ä
¿
ä
N
L
ˆ
ª
,
•
[
„
[9–15].
DOI:10.12677/pm.2023.1361711678
n
Ø
ê
Æ
4
Œ
e
z
= (
e
x
>
,
e
y
>
)
>
•
Ï
L
,
˜
Ž
{
¦
2
Â
Q
:
X
Ú
(1.1)
O
Ž
)
,
½
Â
Ù
(
•
Ø
•
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
) =min
(
∆
A,
∆
B,
∆
u,
∆
v
)
∈F
1
"
θ
1
k
∆
A
k
F
θ
2
k
∆
B
k
F
λ
|
∆
u
k
F
µ
|
∆
v
k
F
#
F
,
(1.2)
Ù
¥
F
1
=
(
∆
A,
∆
B
∆
u,
∆
v
:
"
A
+∆
A
−
(
B
+∆
B
)
B
+∆
BA
+∆
A
#"
e
x
e
y
#
=
"
u
+∆
v
v
+∆
v
#)
,
(1.3)
Ù
¥
θ
1
,θ
2
,λ
,
µ
L
«
ë
ê
.
˜
‡
-
‡
À
J
´
,
A
,
B
,
u
,
v
Ñ
Ø
u
"
ž
,
e
θ
1
=
1
k
A
k
F
,
e
θ
2
=
1
k
B
k
F
,λ
=
1
k
u
k
2
,µ
=
1
k
v
k
2
,
l
Ñ
ƒ
é
(
z
•
Ø
η
s
1
(
e
x,
e
y
) =
η
(
e
θ
1
,
e
θ
2
,
e
λ,
e
µ
)
s
1
(
e
x,
e
y
)
.
(1.4)
2.
ý
•
£
Ú
n
2.1
[1]
u
∈
R
m
Ú
v
∈
R
n
®
•
.
½
Â
Y
=
{
Y
∈
R
n
×
m
:
Yu
=
v
}
.
K
,
Y6
=
∅
…
=
vu
†
u
=
v
,
…
3
d
œ
¹
e
,
?
¿
Y
∈Y
Œ
L
«
•
Y
=
vu
†
+
T
(
I
m
−
uu
†
)
,T
∈
R
n
×
m
.
Ú
n
2.2
[8,16]
a,b
∈
R
n
®
•
.
½
Â
F
=
F
∈
R
n
×
n
:
Fa
=
b,F
>
=
F.
K
,
F6
=
∅
…
=
ba
†
b
=
a
,
…
3
d
œ
¹
e
,
?
¿
F
∈F
Œ
L
«
•
F
=
ba
†
+(
a
†
)
>
b
>
(
I
n
−
aa
†
)+(
I
n
−
aa
†
)
Z
(
I
n
−
aa
†
)
.
Ù
¥
Z
∈
SR
n
×
n
.
3.
Ì
‡
(
J
3ù
Ü
©
,
·
‚
òO
Ž
þ
ã
œ
¹
¥
(
z
•
Ø
η
(
θ
1
,θ
2
,λ,µ
)
s
1
.
3
d
ƒ
c
,
·
‚
I
‡
k
•
Ä
Ü
DOI:10.12677/pm.2023.1361711679
n
Ø
ê
Æ
4
Œ
©
(
•
Ø
η
(
θ
1
,θ
2
)(
e
x,
e
y
)
s
1
,
=
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
) =min
(∆
A,
∆
B
)
∈F
0
1
(
θ
1
k
∆
A
k
F
,θ
2
k
∆
B
k
F
)
>
2
,
(3.1)
Ù
¥
F
0
1
=
(
(
∆
A,
∆
B
) :
h
θ
1
∆
Aθ
2
∆
B
i
"
1
θ
1
(
e
x
+
e
y
)
θ
2
(
e
x
−
e
y
)
#
=
r
u
+
r
v
)
.
(3.2)
½
n
3.1
(
e
x,
e
y
)
>
´
‚
5
X
Ú
(1.1)
˜
‡
O
Ž
)
,
…
e
x
6
= 0
,
e
y
6
= 0.
·
‚
k
[
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
)]
2
=
1
α
1
k
r
u
+
r
v
k
2
2
,
Ù
¥
α
1
=
1
θ
2
1
k
e
x
+
e
y
k
2
2
+
1
θ
2
2
k
e
x
−
e
y
k
2
2
,
r
u
=
u
−
A
e
x
+
B
e
y,r
v
=
v
−
B
e
x
−
A
e
y.
y
²
:
d
ª
(3.2)
•
,(
4
A,
4
B
)
∈F
0
1
…
=
∆
A,
∆
B
÷
v
∆
A
e
x
=
r
u
+∆
B
e
y,
∆
B
e
x
=
r
v
−
∆
A
e
y.
(3.3)
ò
Ú
n
2.1
A^u
(3.4),
K
é
u
?
¿
∆
B
∈
R
n
×
n
,
Œ
h
θ
1
∆
Aθ
2
∆
B
i
=
h
(
r
u
+
r
v
)
i
"
1
θ
1
(
e
x
+
e
y
)
1
θ
2
(
e
x
−
e
y
)
#
†
+
Z
I
n
−
"
1
θ
1
(
e
x
+
e
y
)
1
θ
2
(
e
x
−
e
y
)
#"
1
θ
1
(
e
x
+
e
y
)
1
θ
2
(
e
x
−
e
y
)
#
†
,
(3.4)
Ù
¥
Z
∈
R
n
×
n
.
²
O
Ž
"
1
θ
1
(
e
x
+
e
y
)
1
θ
2
(
e
x
−
e
y
)
#
†
=
h
1
θ
1
(
e
x
+
e
y
)
>
1
θ
2
(
e
x
−
e
y
)
>
i
"
1
θ
1
(
e
x
+
e
y
)
1
θ
2
(
e
x
−
e
y
)
#!
−
1
h
1
θ
1
(
e
x
+
e
y
)
>
1
θ
2
(
e
x
−
e
y
)
>
i
=
1
1
θ
2
1
k
e
x
+
e
y
k
2
2
+
1
θ
2
2
k
e
x
−
e
y
k
2
2
h
1
θ
1
(
e
x
+
e
y
)
>
1
θ
2
(
e
x
−
e
y
)
>
i
,
(3.5)
ò
(3.5)
“
\
(3.4)
h
θ
1
∆
Aθ
2
∆
B
i
=
1
1
θ
2
1
k
e
x
+
e
y
k
2
2
+
1
θ
2
2
k
e
x
−
e
y
k
2
2
h
(
r
u
+
r
v
)
ih
1
θ
1
(
e
x
+
e
y
)
>
1
θ
2
(
e
x
−
e
y
)
>
i
+
Z
I
n
−
1
1
θ
2
1
k
e
x
+
e
y
k
2
2
+
1
θ
2
2
k
e
x
−
e
y
k
2
2
"
1
θ
1
(
e
x
+
e
y
)
1
θ
2
(
e
x
−
e
y
)
#
h
1
θ
1
(
e
x
+
e
y
)
>
1
θ
2
(
e
x
−
e
y
)
>
i
!
.
(3.6)
DOI:10.12677/pm.2023.1361711680
n
Ø
ê
Æ
4
Œ
•
Ä
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
)
½
Â
(3.1),
(
Ü
(3.5),(3.6),
·
‚
[
η
(
θ,θ
1
)
s
1
(
e
x,
e
y
)]
2
=min
Z
∈
R
n
×
n
∆
A,
∆
B
∈
R
n
×
n
θ
2
1
k
∆
A
k
2
F
+
θ
2
2
k
∆
B
k
2
F
=min
∆
A,
∆
B
∈
R
n
×
n
p
(∆
A,
∆
B
)
,
Ù
¥
P
(∆
A,
∆
B
)=
h
(
r
u
+
r
v
)
ih
1
θ
(
e
x
+
e
y
)
>
1
θ
1
(
e
x
−
e
y
)
>
i
2
F
1
θ
2
1
k
e
x
+
e
y
k
2
2
+
1
θ
2
2
k
e
x
−
e
y
k
2
2
+
Z
I
−
1
1
θ
2
1
k
e
x
+
e
y
k
2
2
+
1
θ
2
2
k
e
x
−
e
y
k
2
2
"
1
θ
1
(
e
x
+
e
y
)
1
θ
2
(
e
x
−
e
y
)
#
h
1
θ
1
(
e
x
+
e
y
)
>
1
θ
2
(
e
x
−
e
y
)
>
i
!
2
F
=
1
1
θ
2
1
k
e
x
+
e
y
k
2
2
+
1
θ
2
2
k
e
x
−
e
y
k
2
2
k
r
u
+
r
v
k
2
2
.
=
•
½
n
3.1
L
ˆ
ª
.
½
n
3.2
b
½
n
3.1
¥
^
‡
¤
á
.
d
(1.2),(1.4),
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
= (
1
α
1
−
α
2
)
k
r
u
k
2
2
+(
1
α
1
−
α
2
)
k
r
v
k
2
2
−
(
2
α
1
+2
α
2
)
r
>
u
r
v
,
(3.7)
Ù
¥
α
2
=
1
λ
2
+
1
µ
2
−
1
λ
4
µ
2
.
y
²
:
d
½
Â
(1.2)
Ú
½
n
3.1
L
ˆ
ª
,
Œ
•
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=min
∆
f
∈
R
m
,
∆
g
∈
R
n
b
X
(∆
u,
∆
v
)
,
(3.8)
Ù
¥
b
X
(∆
u,
∆
v
)=
1
α
1
k
(
r
u
+∆
u
)+(
r
v
+∆
v
)
k
2
2
+
λ
2
k
∆
u
k
2
2
+
µ
2
k
∆
v
k
2
2
=[
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
)]
2
+
1
α
1
h
∆
u
>
∆
v
>
i
"
λ
2
I
n
I
n
I
n
µ
2
I
n
#"
∆
u
∆
v
#
+
2
α
1
h
∆
u
>
∆
v
>
i
"
r
u
+
r
v
r
u
+
r
v
#
.
(3.9)
N
´
y
²
"
λ
2
I
n
I
n
I
n
µ
2
I
n
#
´¢
é
¡
½
Ý
.
K
"
∆
u
∆
v
#
=
−
"
λ
2
I
n
I
n
I
n
µ
2
I
n
#
−
1
"
r
u
+
r
v
r
u
+
r
v
#
ž
,(3.9)
•
Š
.
DOI:10.12677/pm.2023.1361711681
n
Ø
ê
Æ
4
Œ
ƒ
A
/
,
²
L
˜
X
E
,
O
Ž
,
·
‚
í
Ñ
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
= (
1
α
1
−
α
2
)
k
r
u
k
2
2
+(
1
α
1
−
α
2
)
k
r
v
k
2
2
−
(
2
α
1
+2
α
2
)
r
>
u
r
v
,
½
n
y
²
¤
.
4.
e
x
6
=0
,
e
y
=0
1
˜
«
œ
¹
e
5
Ü
©
·
‚
ò
?
Ø
e
x
6
= 0
,
e
y
=0
ž
1
˜
«
œ
¹
e
(
z
•
Ø
η
(
θ
1
,θ
2
,λ,µ
)
s
1
.
Ó
,
·
‚
I
‡
k
O
Ž
Ü
©
(
•
Ø
η
(
θ
1
,θ
2
)(
e
x,
e
y
)
s
1
,
=
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
) =min
(∆
A,
∆
B
)
∈F
1
1
(
θ
1
k
∆
A
k
F
,θ
2
k
∆
B
k
F
)
>
2
,
(4.1)
Ù
¥
F
1
1
=
(
(
∆
A,
∆
B
) :
"
A
+∆
A
−
(
B
+∆
B
)
B
+∆
BA
+∆
A
#"
e
x
e
y
#
=
"
u
v
#)
.
(4.2)
½
n
4.1
(
e
x,
e
y
)
>
´
‚
5
X
Ú
(1.1)
˜
‡
O
Ž
)
,
…
e
x
6
= 0
,
e
y
= 0.
·
‚
k
[
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
)]
2
=
θ
2
1
k
r
u
1
k
2
2
k
e
x
k
2
2
+
θ
2
2
k
r
v
1
k
2
2
k
e
x
k
2
2
,
Ù
¥
r
u
1
=
u
−
A
e
x,r
v
1
=
v
−
B
e
x.
(4.3)
y
²
:
d
(4.2)
∆
A
e
x
=
r
u
1
,
∆
B
e
x
=
r
v
1
,
ò
Ú
n
2.1
^u
(4.3)
Œ
∆
A
=
r
u
1
e
x
†
+
Z
1
(
I
n
−
e
x
e
x
†
)
,
∆
B
=
r
v
1
e
x
†
+
Z
2
(
I
n
−
e
x
e
x
†
)
.
Ù
¥
Z
1
,Z
2
∈
R
n
×
n
.
·
‚
Œ
±
Ñ
k
∆
A
k
2
F
=
k
r
u
1
k
2
2
k
e
x
k
2
2
+
k
Z
1
(
I
−
e
x
e
x
†
)
k
2
F
,
(4.4)
k
∆
B
k
2
F
=
k
r
v
1
k
2
2
k
e
x
k
2
2
+
k
Z
2
(
I
−
e
x
e
x
†
)
k
2
F
.
(4.5)
DOI:10.12677/pm.2023.1361711682
n
Ø
ê
Æ
4
Œ
•
Ä
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
)
½
Â
(4.1),
(
Ü
(4.4),(4.5),
Œ
[
η
(
θ,θ
1
)
s
1
(
e
x,
e
y
)]
2
=min
Z
1
∈
R
n
×
n
,Z
2
∈
R
n
×
n
∆
A,
∆
B
∈
R
n
×
n
θ
2
1
k
∆
A
k
2
F
+
θ
2
2
k
∆
B
k
2
F
=
θ
2
1
k
r
u
1
k
2
2
k
e
x
k
2
2
+
θ
2
2
k
r
v
1
k
2
2
k
e
x
k
2
2
,
(4.6)
=
½
n
y
²
¤
.
½
n
4.2
b
½
n
4.1
¥
^
‡
¤
á
,
d
(1.2),(1.4),
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=
λ
2
θ
2
1
β
1
k
r
u
1
k
2
2
+
µ
2
θ
2
2
β
2
k
r
v
1
k
2
2
,
(4.7)
Ù
¥
β
1
=
λ
2
k
e
x
k
2
2
+
θ
2
1
,β
2
=
µ
2
k
e
x
k
2
2
+
θ
2
2
.
y
²
:
d
½
Â
(1.2)
Ú
½
n
4.1
L
ˆ
ª
,
Œ
•
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=min
∆
u
∈
R
n
,
∆
v
∈
R
n
b
X
(∆
u
1
,
∆
v
1
)
,
(4.8)
Ù
¥
b
X
(∆
u
1
,
∆
v
1
)=
θ
2
1
k
e
x
k
2
2
k
r
u
1
+∆
u
1
k
2
2
+
θ
2
2
k
e
x
k
2
2
k
r
v
1
+∆
v
1
k
2
2
=[
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
)]
2
+∆
u
>
1
(
θ
2
1
k
e
x
k
2
2
I
n
+
λ
2
I
n
)∆
u
1
+2∆
u
>
1
θ
2
1
r
u
1
k
e
x
k
2
2
+∆
v
>
1
(
θ
2
2
k
e
x
k
2
2
I
n
+
µ
2
I
n
)∆
v
1
+2∆
v
>
1
θ
2
2
r
v
1
k
e
x
k
2
2
.
N
´
y
²
θ
2
1
k
e
x
k
2
2
I
n
+
λ
2
I
n
,
θ
2
2
k
e
x
k
2
2
I
n
+
µ
2
I
n
´¢
é
¡
½
Ý
,
K
∆
u
=
−
(
θ
2
1
k
e
x
k
2
2
I
n
+
λ
2
I
n
)
−
1
θ
2
1
r
u
1
k
e
x
k
2
2
,
∆
v
=
−
(
θ
2
2
k
e
x
k
2
2
I
n
+
µ
2
I
n
)
−
1
θ
2
2
r
v
1
k
e
x
k
2
2
ž
,
þ
ª
•
Š
.
ƒ
A
/
,
²
L
˜
X
E
,
O
Ž
,
·
‚
í
Ñ
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=
λ
2
θ
2
1
β
1
k
r
u
1
k
2
2
+
µ
2
θ
2
2
β
2
k
r
v
1
k
2
2
,
K
½
n
y
²
¤
.
DOI:10.12677/pm.2023.1361711683
n
Ø
ê
Æ
4
Œ
5.
e
x
6
=0
,
e
y
=0
1
«
œ
¹
e
5
Ü
©
·
‚
ò
?
Ø
e
x
6
= 0
,
e
y
= 0
ž
1
«
œ
¹
e
(
z
•
Ø
η
(
θ
1
,θ
2
,λ,µ
)
s
1
.
Ó
§
·
‚
I
‡
k
O
Ž
Ü
©
(
•
Ø
η
(
θ
1
,θ
2
)(
e
x,
e
y
)
s
1
,
=
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
) =min
(∆
A,
∆
B
)
∈F
2
1
(
θ
1
k
∆
A
k
F
,θ
2
k
∆
B
k
F
)
>
2
,
(5.1)
Ù
¥
F
2
1
=
(
(
∆
A,
∆
B
) :
"
A
+∆
A
−
(
B
+∆
B
)
B
+∆
BA
+∆
A
#"
e
x
e
y
#
=
"
u
v
#
: ∆
A
= ∆
A
>
,
∆
B
= ∆
B
>
)
.
(5.2)
½
n
5.1
(
e
x,
e
y
)
>
´
‚
5
X
Ú
(1.1)
˜
‡
O
Ž
)
,
…
e
x
6
= 0
,
e
y
= 0,
A
=
A
>
,
B
=
B
>
.
·
‚
k
[
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
)]
2
=
2
θ
2
1
k
r
u
1
k
2
2
k
e
x
k
2
2
+
2
θ
2
2
k
r
v
1
k
2
2
k
e
x
k
2
2
−
θ
2
1
(
r
>
u
1
e
x
)
2
k
e
x
k
4
2
−
θ
2
2
(
r
>
v
1
e
x
)
2
k
e
x
k
4
2
.
y
²
:
d
(5.2)
∆
A
e
x
=
r
u
1
,
∆
B
e
x
=
r
v
1
.
(5.3)
ò
Ú
n
2.2
^u
(5.3)
Œ
∆
A
=
r
u
1
e
x
†
+(
e
x
†
)
>
r
>
u
1
(
I
n
−
e
x
e
x
†
)+(
I
n
−
e
x
e
x
†
)
Z
3
(
I
n
−
e
x
e
x
†
)
,
∆
B
=
r
v
1
e
x
†
+(
e
x
†
)
>
r
>
v
1
(
I
n
−
e
x
e
x
†
)+(
I
n
−
e
x
e
x
†
)
Z
4
(
I
n
−
e
x
e
x
†
)
.
Ù
¥
Z
3
,Z
4
∈
SR
n
×
n
,
·
‚
Œ
±
k
∆
A
k
2
F
=
k
r
u
k
2
2
k
e
x
k
2
2
+
k
(
e
x
†
)
>
r
>
u
1
(
I
n
−
e
x
e
x
†
)
k
2
F
+
k
(
I
n
−
e
x
e
x
†
)
Z
3
(
I
n
−
e
x
e
x
†
)
k
2
F
,
(5.4)
k
∆
B
k
2
F
=
k
r
v
k
2
2
k
e
x
k
2
2
+
k
(
e
x
†
)
>
r
>
v
1
(
I
n
−
e
x
e
x
†
)
k
2
F
+
k
(
I
n
−
e
x
e
x
†
)
Z
4
(
I
n
−
e
x
e
x
†
)
k
2
F
.
(5.5)
•
Ä
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
)
½
Â
(5.1),
(
Ü
(5.4),(5.5),
Œ
[
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
)]
2
=min
Z
3
∈
SR
n
×
n
,Z
4
∈
R
n
×
n
∆
A,
∆
B
∈
R
n
×
n
θ
2
1
k
∆
A
k
2
F
+
θ
2
2
k
∆
B
k
2
F
=min
∆
A,
∆
B
∈
R
n
×
n
p
(∆
A,
∆
B
)
,
Ù
¥
P
(∆
A,
∆
B
) =
2
θ
2
1
k
r
u
1
k
2
2
k
e
x
k
2
2
−
θ
2
1
(
r
>
u
1
e
x
)
2
k
e
x
k
4
2
+
2
θ
2
2
k
r
v
1
k
2
2
k
e
x
k
2
2
−
θ
2
2
(
r
>
v
1
e
x
)
2
k
e
x
k
4
2
,
DOI:10.12677/pm.2023.1361711684
n
Ø
ê
Æ
4
Œ
=
•
½
n
4.3
L
ˆ
ª
.
½
n
5.2
b
½
n
5.1
¥
^
‡
¤
á
.
d
(1.2),(1.4),
Œ
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=
2
θ
2
1
β
11
+4
θ
2
1
β
11
k
e
x
k
2
2
k
r
u
1
k
2
2
−
θ
2
1
β
1
β
11
+3
θ
4
1
β
1
−
θ
6
1
k
e
x
k
4
2
β
1
β
11
(
r
>
u
1
e
x
)
2
+
2
θ
2
2
β
22
+4
θ
2
2
β
22
k
e
x
k
2
2
k
r
v
1
k
2
2
−
θ
2
2
β
2
β
22
+3
θ
4
2
β
2
−
θ
6
2
k
e
x
k
4
2
β
2
β
22
(
r
>
v
1
e
x
)
2
,
Ù
¥
β
11
= 2
θ
2
1
+
λ
2
k
e
x
k
2
2
,β
22
= 2
θ
2
2
+
µ
2
k
e
x
k
2
2
.
y
²
:
d
½
Â
(1.2)
Ú
½
n
5.1
L
ˆ
ª
,
Œ
•
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=min
∆
u
∈
R
n
,
∆
v
∈
R
n
b
X
(∆
u
1
,
∆
v
1
)
,
Ù
¥
b
X
(∆
u
1
,
∆
v
1
)=
2
θ
2
1
k
r
u
1
+∆
u
1
k
2
2
k
e
x
k
2
2
−
θ
2
1
((
r
u
1
+∆
u
1
)
>
e
x
)
2
k
e
x
k
4
2
+
λ
2
k
∆
u
1
k
2
2
+
2
θ
2
2
k
r
v
1
+∆
v
1
k
2
2
k
e
x
k
2
2
−
θ
2
2
((
r
v
1
+∆
v
1
)
>
e
x
)
2
k
e
x
k
4
2
+
µ
2
k
∆
v
1
k
2
2
=[
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
)]
2
+∆
u
>
(
2
θ
2
1
k
e
x
k
2
2
I
n
+
λ
2
I
n
−
θ
2
1
e
x
e
x
>
k
e
x
k
4
2
)∆
u
+2∆
u
>
(
2
θ
2
1
r
u
k
e
x
k
2
2
−
θ
2
1
(
e
x
>
r
u
)
e
x
k
e
x
k
4
2
)
+∆
v
>
(
2
θ
2
2
k
e
x
k
2
2
I
n
+
µ
2
I
n
−
θ
2
2
e
x
e
x
>
k
e
x
k
4
2
)∆
v
+2∆
v
>
(
2
θ
2
2
r
u
k
e
x
k
2
2
−
θ
2
2
(
e
x
>
r
v
)
e
x
k
e
x
k
4
2
)
.
(5.6)
N
´
y
²
2
θ
2
1
k
e
x
k
2
2
I
n
+
λ
2
I
n
−
θ
2
1
e
x
e
x
>
k
e
x
k
4
2
,
2
θ
2
2
k
e
x
k
2
2
I
n
+
µ
2
I
n
−
θ
2
2
e
x
e
x
>
k
e
x
k
4
2
´¢
é
¡
½
Ý
,
K
∆
u
=
−
(
2
θ
2
1
k
e
x
k
2
2
I
n
+
λ
2
I
n
−
θ
2
1
e
x
e
x
>
k
e
x
k
4
2
)
−
1
(
2
θ
2
1
r
u
k
e
x
k
2
2
−
θ
2
1
(
e
x
>
r
u
)
e
x
k
e
x
k
4
2
)
,
∆
v
=
−
(
2
θ
2
2
k
e
x
k
2
2
I
n
+
µ
2
I
n
−
θ
2
2
e
x
e
x
>
k
e
x
k
4
2
)
−
1
(
2
θ
2
2
r
u
k
e
x
k
2
2
−
θ
2
2
(
e
x
>
r
v
)
e
x
k
e
x
k
4
2
)
ž
,(5.6)
•
Š
,
²
L
˜
X
E
,
O
Ž
,
·
‚
í
Ñ
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=
2
θ
2
1
β
11
+4
θ
2
1
β
11
k
e
x
k
2
2
k
r
u
1
k
2
2
−
θ
2
1
β
1
β
11
+3
θ
4
1
β
1
−
θ
6
1
k
e
x
k
4
2
β
1
β
11
(
r
>
u
1
e
x
)
2
+
2
θ
2
2
β
22
+4
θ
2
2
β
22
k
e
x
k
2
2
k
r
v
1
k
2
2
−
θ
2
2
β
2
β
22
+3
θ
4
2
β
2
−
θ
6
2
k
e
x
k
4
2
β
2
β
22
(
r
>
v
1
e
x
)
2
.
=
½
n
y
.
e
5ü
«
œ
¹
y
²
†
þ
¡
ƒ
q
,
Ž
Ñ
.
DOI:10.12677/pm.2023.1361711685
n
Ø
ê
Æ
4
Œ
í
Ø
1
(
e
x,
e
y
)
>
´
‚
5
X
Ú
(1.1)
˜
‡
O
Ž
)
,
…
e
x
6
= 0
,
e
y
= 0,
B
=
B
>
,
·
‚
k
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=
λ
2
θ
2
1
β
1
k
r
u
1
k
2
2
+
2
θ
2
2
β
22
+4
θ
2
2
β
22
k
e
x
k
2
2
k
r
v
1
k
2
2
−
θ
2
2
β
2
β
22
+3
θ
4
2
β
2
−
θ
6
2
k
e
x
k
4
2
β
2
β
22
(
r
>
v
1
e
x
)
2
.
í
Ø
2
(
e
x,
e
y
)
>
´
‚
5
X
Ú
(1.1)
˜
‡
O
Ž
)
,
…
e
x
6
= 0
,
e
y
= 0,
A
=
A
>
,
·
‚
k
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=
2
θ
2
1
β
11
+4
θ
2
1
β
11
k
e
x
k
2
2
k
r
u
1
k
2
2
−
θ
2
1
β
1
β
11
+3
θ
4
1
β
1
−
θ
6
1
k
e
x
k
4
2
β
1
β
11
(
r
>
u
1
e
x
)
2
+
µ
2
θ
2
2
β
2
k
r
v
1
k
2
2
.
6.
e
x
=0
,
e
y
6
=0
œ
¹
e
5
?
Ø
e
x
=0
,
e
y
6
=0
œ
¹
,
y
²
†
þ
¡
ƒ
q
,
Ž
Ñ
.
½
n
6.1
(
e
x,
e
y
)
>
´
‚
5
X
Ú
(1.1)
˜
‡
O
Ž
)
,
…
e
x
= 0
,
e
y
6
= 0.
·
‚
k
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=
λ
2
θ
2
1
ω
1
k
r
v
2
k
2
2
+
µ
2
θ
2
2
ω
2
k
r
u
2
k
2
2
,
Ù
¥
r
u
2
=
u
+
B
e
y,r
v
2
=
v
−
A
e
y,
ω
1
=
θ
2
1
+
λ
2
k
e
y
k
2
2
,ω
2
=
θ
2
2
+
µ
2
k
e
y
k
2
2
.
½
n
6.2
(
e
x,
e
y
)
>
´
‚
5
X
Ú
(1.1)
˜
‡
O
Ž
)
,
…
e
x
= 0
,
e
y
6
= 0,
A
=
A
>
,
B
=
B
>
.
·
‚
k
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=
2
θ
2
1
ω
11
+4
θ
2
1
ω
11
k
e
y
k
2
2
k
r
v
2
k
2
2
−
θ
2
1
ω
1
ω
11
+3
θ
4
1
ω
1
−
θ
6
1
k
e
y
k
4
2
ω
1
ω
11
(
r
>
v
2
e
y
)
2
(6.1)
+
2
θ
2
2
ω
22
+4
θ
2
2
ω
22
k
e
y
k
2
2
k
r
u
2
k
2
2
−
θ
2
2
ω
2
ω
22
+3
θ
4
2
ω
2
−
θ
6
2
k
e
y
k
4
2
ω
2
ω
22
(
r
>
u
2
e
y
)
2
,
(6.2)
Ù
¥
ω
11
= 2
θ
2
1
+
λ
2
k
e
y
k
2
2
,ω
22
= 2
θ
2
2
+
µ
2
k
e
y
k
2
2
.
½
n
6.3
(
e
x,
e
y
)
>
´
‚
5
X
Ú
(1.1)
˜
‡
O
Ž
)
,
…
e
x
= 0
,
e
y
6
= 0,
B
=
B
>
.
·
‚
k
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=
λ
2
θ
2
1
ω
1
k
r
v
2
k
2
2
+
2
θ
2
2
ω
22
+4
θ
2
2
ω
22
k
e
y
k
2
2
k
r
u
2
k
2
2
−
θ
2
2
ω
2
ω
22
+3
θ
4
2
ω
2
−
θ
6
2
k
e
y
k
4
2
ω
2
ω
22
(
r
>
u
2
e
y
)
2
.
½
n
6.4
(
e
x,
e
y
)
>
´
‚
5
X
Ú
(1.1)
˜
‡
O
Ž
)
,
…
e
x
= 0
,
e
y
6
= 0,
A
=
A
>
.
·
‚
k
[
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
)]
2
=
2
θ
2
1
ω
11
+4
θ
2
1
ω
11
k
e
y
k
2
2
k
r
v
2
k
2
2
−
θ
2
1
ω
1
ω
11
+3
θ
4
1
ω
1
−
θ
6
1
k
e
y
k
4
2
ω
1
ω
11
(
r
>
v
2
e
y
)
2
+
µ
2
θ
2
2
ω
2
k
r
u
2
k
2
2
.
DOI:10.12677/pm.2023.1361711686
n
Ø
ê
Æ
4
Œ
7.
A^
3ù
Ü
©
,
·
‚
ò
^
•[
ê
Š
~
f
y
²
½
n
3.1,3.2,
¿
…
O
Ž
Ñ
•[
ê
â
.
Ù
{
½
n
y
a
q
,
Ž
Ñ
.
¤
k
ê
Š
O
Ž
Ñ
3
MATLABR2016a
¥
±
Å
ì
°
Ý
2
.
2204
×
10
−
16
?
1
.
·
‚
•
Ä
‚
5
X
Ú
(1.1)
"
A
−
B
BA
#"
x
y
#
=
"
u
v
#
.
Ù
¥
A
=
2
−
801
−
50
−
45
4
−
3
−
1
−
2
36
−
71
, B
=
2103
1401
0751
10
−
3
021
,
u
=
10
6
5
0
0
, v
=
10
−
6
0
0
1
.
¦
^
Ü
©
À
Ì
Gauss
ž
{
,
·
‚
˜
‡
O
Ž
)
e
z
= (
e
x
>
,
e
y
>
)
>
,
Ù
¥
e
x
=
−
2
.
550948811691706
×
10
4
−
8
.
103528926046949
×
10
4
−
5
.
127357916480393
×
10
4
7
.
085379024155514
,
e
y
=
1
.
111396285339100
×
10
5
1
.
416787831660810
×
10
4
2
.
818042030869885
×
10
4
−
1
.
894433357643171
×
10
5
.
ò
þ
ã
(
J
“
\
½
n
3.1,3.2,
·
‚
Œ
±
η
(
e
z
) = 2
.
767658843372967
×
10
−
17
,
η
(
θ
1
,θ
2
)
s
1
(
e
x,
e
y
) = 1
.
207459273255117
×
10
−
33
,
η
(
θ
1
,θ
2
,λ,µ
)
s
1
(
e
x,
e
y
) = 1
.
185846126215313
×
10
4
.
l
þ
¡
(
J
¥
Œ
±
w
Ñ
,
Ü
©
À
Ì
Gauss
ž
{
´
•
-
½
,
Ø
´
r
-
½
.
(
J
L
²
,
T
(
J
Ñ
(
5
•
Ø
L
ˆ
ª
é
u
u
¢
S
2
Â
Q
:
¯
K
Ž
{
-
½
5
´
k^
.
Ù
¦
½
n
y
†
þ
¡
ƒ
q
,
3ù
p
·
‚
Ø
2
y
.
ë
•
©
z
[1]Benzi,M.,Golub,G.H.andLiesen,J.(2005)NumericalSolutionofSaddlePointProblems.
ActaNumerica
,
14
,1-137.https://doi.org/10.1017/S0962492904000212
[2]Xiang, H., Wei, Y.M.and Diao, H.A.(2006) Perturbation Analysisof GeneralizedSaddle Point
Systems.
LinearAlgebraanditsApplications
,
419
,8-23.
DOI:10.12677/pm.2023.1361711687
n
Ø
ê
Æ
4
Œ
https://doi.org/10.1016/j.laa.2006.03.041
[3]Xu,W.(2009)New PerturbationAnalysisfor GeneralizedSaddlePointSystems.
Calcolo
,
46
,
25-36.https://doi.org/10.1007/s10092-009-0157-8
[4]Xu,W.W.,Liu,M.M.,Zhu,L.andZuo,H.F.(2017)NewPerturbationBoundsAnalysisof
aKindofGeneralizedSaddlePointSystems.
EastAsianJournalonAppliedMathematics
,
7
,
116-124.https://doi.org/10.4208/eajam.100616.031216a
[5]Sun,J.G.(1999)StructuredBackwardErrorsforKKTSystems.
LinearAlgebraanditsAp-
plications
,
288
,75-88.https://doi.org/10.1016/S0024-3795(98)10184-2
[6]Yang,X.D.,Dai,H.andHe,Q.Q.(2011)ConditionNumbersandBackwardPerturbation
Bound for LinearMatrixEquations.
NumericalLinearAlgebrawithApplications
,
18
,155-165.
https://doi.org/10.1002/nla.725
[7]Rigal,J.L.andGaches,J.(1967)OntheCompatibilityofaGivenSolutionwiththeDataof
aLinearSystem.
JournaloftheACM
,
14
,543-548.https://doi.org/10.1145/321406.321416
[8]Wilkinson,J.(1965)TheAlgebraicEigenvalueProblem.OxfordUniversityPress,Oxford.
[9]Xiang,H.andWei,Y.M.(2007)OnNormwiseStructuredBackwardErrorsforSaddlePoint
Systems.
SIAMJournalonMatrixAnalysisandApplications
,
29
,838-849.
https://doi.org/10.1137/060663684
[10]Chen,X.S.,Li,W.,Chen, X.J. and Liu,J.(2012)Structured Backward Errors for Generalized
SaddlePointSystems.
LinearAlgebraanditsApplications
,
436
,3109-3119.
https://doi.org/10.1016/j.laa.2011.10.012
[11]Eisenstat,S.C., Gratton,S. and Titley-peloquin, D. (2017) On the Symmetric Componentwise
RelativeBackwardErrorforLinearSystemsofEquations.
SIAMJournalonMatrixAnalysis
andApplications
,
38
,1100-1115.https://doi.org/10.1137/140986566
[12]Higham,D.J.andHigham,N.J.(1992)BackwardErrorandConditionofStructuredLinear
Systems.
SIAMJournalonMatrixAnalysisandApplications
,
13
,162-175.
https://doi.org/10.1137/0613014
[13]Higham,N.J.(2002)AccuracyandStabilityofNumericalAlgorithms,2ndEdition,SIAM,
Philadelphia.
[14]Rump,S.M.(2015)TheComponentwiseStructuredandUnstructuredBackwardErrorsCan
BeArbitrarilyFarApart.
SIAMJournalonMatrixAnalysisandApplications
,
36
,385-392.
https://doi.org/10.1137/140985500
[15]Stewart,G.W.andSun,J.G.(1990)MatrixPerturbationTheory.AcademicPress,Boston.
[16]Rump,S.M.(2015)TheComponentwiseStructuredandUnstructuredBackwardErrorsCan
BeArbitrarilyFarApart.
SIAMJournalonMatrixAnalysisandApplications
,
36
,385-392.
https://doi.org/10.1137/140985500
DOI:10.12677/pm.2023.1361711688
n
Ø
ê
Æ