1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
integer function issymmetric(in)
c return 1 if matrix at position in is symmetric
include '../stack.h'
double precision sr
c
integer iadr,sadr
c
iadr(l)=l+l-1
sadr(l)=(l/2)+1
c
issymmetric=0
nnn=top-rhs+in
l=lstk(nnn)
il=iadr(l)
m=istk(il+1)
n=istk(il+2)
l=sadr(il+4)
nn=m*n
if (m.ne.n) return
issymmetric =0
if (istk(il+3).eq.0) then
do 20 j = 1,n
do 19 i = 1,j
ls = l + (i-1) + (j-1)*n
ll = l + (i-1)*n + (j-1)
sr = abs(stk(ll)-stk(ls))
if (stk(ll)+sr .gt. stk(ll)) goto 21
19 continue
20 continue
issymmetric = 1
21 continue
return
else
if (n .eq. 1) goto 210
do 200 j = 2,n
j1 = j - 1
do 200 i = 1,j1
ls = l + (i-1) + j1*n
ll = l + (i-1)*n + j1
sr = abs(stk(ll)-stk(ls))
si = abs(stk(ll+nn)+stk(ls+nn))
if (stk(ll)+sr.gt.stk(ll) .or. stk(ll+nn)+si.gt.stk(ll+nn))
& goto 230
200 continue
210 do 220 j = 1,n
ll = l + (j-1) + (j-1)*n
if (stk(ll)+abs(stk(ll+nn)) .gt. stk(ll)) goto 230
220 continue
issymmetric = 1
230 continue
return
endif
end
|
