William Stein wrote: > On Fri, Oct 10, 2008 at 7:11 AM, Jason Grout > <[EMAIL PROTECTED]> wrote: >> How do I get a numeric approximation for symbolic expressions that have >> variables? I want to leave the variables alone, but get numeric >> approximations for all constants. For example, here's how it works in >> mathematica: >> >> In[1]:= a:=1+Sqrt[2]*x >> >> In[2]:= a >> >> Out[2]= 1 + Sqrt[2] x >> >> In[3]:= N[a] >> >> Out[3]= 1. + 1.41421 x >> >> >> However, the corresponding thing does not work in Sage: >> >> sage: a=1+sqrt(2)*x >> sage: a >> sqrt(2)*x + 1 >> sage: n(a) >> --------------------------------------------------------------------------- >> TypeError Traceback (most recent call last) > > For polynomials, do this: > > sage: f = 1 + sqrt(2)*x > sage: f.polynomial(RDF) > 1.41421356237*x + 1.0
Aah, thanks. I guess I also now see the f.series command, which does what I originally wanted as well (lets me specify the ring for the coefficients to the series approximation). The general request still stands, though: is there a way to numerically approximate all the constants in a symbolic expression, but keep the variables as variables? Thanks, Jason --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
