Description
If the input is a matrix or a ring element, then the result has the same type, where each real or complex number coefficient that is less than epsilon in absolute value is replaced with zero.
i1 : e = 1e-11;
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i2 : M = random(RR^4,RR^4)
o2 = | .892712 .0258884 .461944 .0741835 |
| .673395 .714827 .775187 .808694 |
| .29398 .89189 .909047 .362835 |
| .632944 .231053 .314897 .706096 |
4 4
o2 : Matrix RR <-- RR
53 53
|
i3 : M * (M + 1) + 1 - M^2 - M
o3 = | 1 0 0 0 |
| 1.11022e-16 1 1.11022e-16 -2.22045e-16 |
| 1.11022e-16 0 1 -2.22045e-16 |
| -2.22045e-16 0 0 1 |
4 4
o3 : Matrix RR <-- RR
53 53
|
i4 : clean_e oo
o4 = | 1 0 0 0 |
| 0 1 0 0 |
| 0 0 1 0 |
| 0 0 0 1 |
4 4
o4 : Matrix RR <-- RR
53 53
|
Cleaning a polynomial is a way to get rid of small terms.
i5 : CC[x];
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i6 : f = product(5,j -> x - exp(2*pi*j*ii/5))
5 4 3
o6 = x + (2.22045e-16 - 1.11022e-16*ii)x - 1.11022e-16*ii*x + (-
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2
1.11022e-16 - 1.11022e-16*ii)x - 1.11022e-16*ii*x - 1 + 5.55112e-16*ii
o6 : CC [x]
53
|
i7 : clean_e f
5
o7 = x - 1
o7 : CC [x]
53
|