On Sat, 5 Dec 2009 03:32:04 -0500 William Stein <[email protected]> wrote:
> On Fri, Dec 4, 2009 at 9:22 PM, taco <[email protected]> wrote: > > > > Sooo.... I am currently working on trying to simplify the resulting > > expressions in sage to shrink them down to a smaller size. Here is > > the problem: I notice that my expressions contain *a lot* of terms > > like this, arctan2(0, looooooooooooong_expression). Now I know that > > arctan2(0,x) = 0 for all x and so this should simplify my > > expressions a great deal. However, I cannot get sage to make this > > simplification for me. Simplify() and simplify_full() do not touch > > these terms. Does anyone have an idea about how to address this > > trigonometric simplification? > > You might find this example useful: > > sage: f = arctan2(0,sin(x)^2) + cos(x^3) + 1/x > sage: g(x,y) = 0 > sage: f.substitute_function(arctan2, g) > 1/x + cos(x^3) Here is another way: sage: t = arctan2(0,x+y^z) + cos(x) + 1/x sage: t 1/x + cos(x) + arctan2(0, y^z + x) sage: w = SR.wild() sage: t.subs({arctan2(0,w):0}) 1/x + cos(x) Cheers, Burcin -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
