[sage-support] Re: assumptions

2011-12-08 Thread kcrisman
We've done a little work on being able to handle stuff like this, but it's still rudimentary (and it basically uses list comprehensions along the lines of the other answer. We'd welcome a ticket about this specific use case. Also, think of the Maxima solve capability as using dummy variables; tha

Re: [sage-support] Re: assumptions

2011-12-08 Thread robin hankin
wow, thank you. I would not have thought of using list comprehensions here. Is there a way to do [s for s in sol if ] thanks Robin On Fri, Dec 9, 2011 at 11:48 AM, achrzesz wrote: > > > On Dec 8, 9:36 pm, robin hankin wrote: >> hello >> >> I have been playing with assumptions().  I want t

[sage-support] Re: assumptions

2011-12-08 Thread achrzesz
On Dec 8, 9:36 pm, robin hankin wrote: > hello > > I have been playing with assumptions().  I want to assume a>b > but solve() gives me a solution which is not consistent with this: > > sage: var('a b') > (a, b) > sage: assume(a>b) > sage: assumptions() > [a > b] > sage: solve([a+b==2,a-b==0],a,

[sage-support] Re: assumptions so that x^n -> 0?

2011-04-16 Thread achrzesz
In the last post one can replace 0.99 by 1 but I wanted to exclude the following situation: sage: n=var('n') sage: x=var('x') sage: x=(1/2)^(1/(n+1)) sage: limit(x^(n+1)/(1-x),n=+oo) +Infinity # OK On 16 Kwi, 15:36, achrzesz wrote: > I must correct myself > W... alpha: > Assuming[x>-0.99,Assumin

[sage-support] Re: assumptions so that x^n -> 0?

2011-04-16 Thread achrzesz
I must correct myself W... alpha: Assuming[x>-0.99,Assuming[x<0.99,Limit[x^(n+1)/(1-x),n->+Infinity]] gives correct answer 0 On 16 Kwi, 09:27, achrzesz wrote: > In W... alpha > Assuming[x>-0.99,x<0.99];Limit[x^(n+1)/(1-x),n->+Infinity] > remains unevaluated, so Maxima, Sage are nol alone > > On 1

[sage-support] Re: assumptions so that x^n -> 0?

2011-04-16 Thread achrzesz
In W... alpha Assuming[x>-0.99,x<0.99];Limit[x^(n+1)/(1-x),n->+Infinity] remains unevaluated, so Maxima, Sage are nol alone On 16 Kwi, 08:18, achrzesz wrote: > One can discuss if in limits of f(x,n) as n-->oo > x may depend on n or not but in the following version: > > sage: assume(x>-0.99,x<0.99

[sage-support] Re: assumptions so that x^n -> 0?

2011-04-15 Thread achrzesz
One can discuss if in limits of f(x,n) as n-->oo x may depend on n or not but in the following version: sage: assume(x>-0.99,x<0.99) sage: n=var('n') sage: sage: limit(x^(n+1)/(1-x), n=infinity) -limit(x^(n + 1), n, +Infinity)/(x - 1) sage: assume(x>0) sage: sage: limit(x^(n+1)/(1-x), n=infinit

[sage-support] Re: assumptions so that x^n -> 0?

2011-04-15 Thread ancienthart
(Respectfully) Then why does splitting the range of values for x into positive, zero and negative ranges work? Joal Heagney -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more opt

[sage-support] Re: assumptions so that x^n -> 0?

2011-04-15 Thread achrzesz
Without additional assumption that x is constant the limit is not zero (take for example x=(1/2)^(1/(n+1)) (W... alpha: Assuming[x=const,x<1,x>0];Limit[x^(n+1)/(1-x),n->+Infinity] 0 OK, Assuming[x<1,x>0];Limit[x^(n+1)/(1-x),n->+Infinity] unevaluated OK) On 15 Kwi, 06:00, Dan Drake wrote: > Why d