On 03/26/2013 12:59 PM, tvn wrote:
In my project I often have inequalities x <= c , x+y <= c, x -y <= c and
to make things uniform, I move all the consts to the lhs, e.g. x <= c
becomes x - c <= 0 . However this becomes problem when c is Infinity
because Sage automatically converts x - oo <= 0 to -Infinity <= 0 and
removes all variables in the original relation. Is there a way to get
around this ? I thought about creating a new variable to represent oo
but thought there could be easier way.
In fact I am not so sure if such action is desirable, for example if I
have x <= oo and x >= oo , this clearly implies x = oo . But treat
these as -oo >= 0 and -oo <= 0 make no sense (-oo >= 0 is False).
Sympy does not use this action and allows relations such as x - oo <= 0 .
Mathematically speaking, why would you want to have a constraint saying
x <= oo? This should behave the same as not having any constraint on x.
Perhaps I am not understanding what you want to constrain here.
--
You received this message because you are subscribed to the Google Groups
"sage-support" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-support?hl=en.
For more options, visit https://groups.google.com/groups/opt_out.
