Re: $Assumptions
- To: mathgroup at smc.vnet.net
- Subject: [mg92630] Re: $Assumptions
- From: Szabolcs Horvat <szhorvat at gmail.com>
- Date: Thu, 9 Oct 2008 06:34:14 -0400 (EDT)
- Organization: University of Bergen
- References: <gci2ia$ta$1@smc.vnet.net>
Ruth Lazkoz Sáez wrote:
> Dear all,
>
> I seem to be unable to change some default options globally.
>
> At the top of my notebook I have
>
> $Assumptions = {MaxRecursion -> 30, AccuracyGoal -> 10};
>
$Assumptions is for mathematica assumptions about symbols, not for
options. Please read the documentation page of $Assumptions.
> Then we I evaluate NIntegrate[Exp[-x^2], {x, 20., 40.}]
> I get 4.78196*10^-176
>
> But if I evaluate NIntegrate[Exp[-x^2], {x, 20., 40.}, MaxRecursion -> 30,
> AccuracyGoal -> 10]
> I get quite a different value, 1.36703*10^-177
Use
SetOptions[NIntegrate, MaxRecursion -> 30, AccuracyGoal -> 10]
etc.
>
> I had the same problem trying to change the options for fonts in plots,
> and then I had to add the options I wanted
> in every plot, I mean evaluation something like $TextStyle ={whatever}
> before doing the plots did not work.
>
> Hope you can help me. Thanks,
>
> Ruth Lazkoz
>