# Command for "∞" values

Roman Chijner shared this question 1 year ago

Hi,

RemoveUndefined works only for "?" variables. There are no commands to remove ∞=1/0 variables(Points)?

See attached file

1

have you tried keepif(x!=1/0,l1)?

1

one possibility more:

1

Thank you for your attention to the problem. For the case of points

l1 = {(1, 2), (1, ∞), (∞, 2), (∞, ∞), (∞, -∞), (- 1, 5)} -???

1

l2 = KeepIf(abs(x(P)) ≠ ∞ ∧ abs(y(P)) ≠ ∞, P, l1)

1

Thanks!!!!!!!!!!!!!!!!!!!!

1

can be used and

l2 = KeepIf(abs(x(P)) abs(y(P)) ≠ ∞, P, l0)

Here I found bugs in the algebra of variables "∞":

algebraic operation

c1 = abs(∞(-∞))= ?

c2 = abs(∞*∞)= ∞ ← -??????

c3 = abs(0*∞)=?

c4= abs(0(-∞))=?

1

Thanks (c2 is correct, we'll fix c1 for next release)

https://tinyurl.com/ComplexMultiply

1

Clear, thanks for the link. Infinity in GG now defined and the command RemoveUndefined[] does not remove it.

It is advisable to have a another command that removes all these uncertainties and ∞, -∞ together.