We disturb the entries of the matrices by a relative error of size epsilon depending on either a discrete with values in {-1,1} or a continuous random variable with values in [-1..1].
i1 : needsPackage "RandomComplexes" o1 = RandomComplexes o1 : Package |
i2 : setRandomSeed "nice example 2"; |
i3 : C=randomChainComplex({1,1,1},{2,2})
3 5 3
o3 = ZZ <-- ZZ <-- ZZ
0 1 2
o3 : ChainComplex
|
i4 : C.dd
3 5
o4 = 0 : ZZ <------------------------- ZZ : 1
| -14 -7 5 5 3 |
| 8 13 1 -17 -21 |
| -13 -15 1 18 21 |
5 3
1 : ZZ <------------------- ZZ : 2
| -11 5 -10 |
| 26 -29 37 |
| 19 -16 23 |
| -41 -1 -22 |
| 46 -16 38 |
o4 : ChainComplexMap
|
i5 : B=disturb(C,1e-4)
3 5 3
o5 = RR <-- RR <-- RR
53 53 53
0 1 2
o5 : ChainComplex
|
i6 : B.dd
3 5
o6 = 0 : RR <-------------------------------------------------- RR : 1
53 | -13.9986 -6.9993 5.0005 5.0005 2.9997 | 53
| 8.0008 12.9987 1.0001 -17.0017 -20.9979 |
| -13.0013 -15.0015 1.0001 18.0018 20.9979 |
5 3
1 : RR <---------------------------------- RR : 2
53 | -10.9989 4.9995 -10.001 | 53
| 26.0026 -29.0029 37.0037 |
| 18.9981 -16.0016 23.0023 |
| -40.9959 -1.0001 -21.9978 |
| 46.0046 -16.0016 37.9962 |
o6 : ChainComplexMap
|
i7 : B.dd^2
3 3
o7 = 0 : RR <---------------------------------------- RR : 2
53 | -.0307969 -.0030031 .00020458 | 53
| -4.26326e-14 .00020002 .148183 |
| -.0780078 .080208 -.239992 |
o7 : ChainComplexMap
|
i8 : B1=disturb(C,1e-4,Strategy => Continuous)
3 5 3
o8 = RR <-- RR <-- RR
53 53 53
0 1 2
o8 : ChainComplex
|
i9 : B1.dd^2
3 3
o9 = 0 : RR <------------------------------------- RR : 2
53 | -.0274814 .0279033 -.0248834 | 53
| -.0316963 -.0630671 .0213659 |
| .0211089 .0524756 -.0148725 |
o9 : ChainComplexMap
|
The result is only approximately a complex