On 3/7/07, Kyle Schalm <[EMAIL PROTECTED]> wrote: > . the question is: how do i evaluate w while leaving z untouched? > (i actually want to do this when R1 is a multivariable ring, but i imagine > it works the same way.) >
Can't you just work with all the variables together, like: sage: P.<z,w>=QQ['z','w'] sage: P _2 = Polynomial Ring in z, w over Rational Field sage: f=z*w sage: f(z,2) _4 = 2*z If, not, you can always make a little function to evaluate (if there is no "built-in" way). sage: R1.<w> = QQ['w'] sage: R2.<z> = R1['z'] sage: f = z*w sage: def my_eval(f,a): ...: coef=f.coeffs() ...: res=0 ...: for i in range(len(coef)): ...: res+=coef[i](a)*z^i ...: return res ...: sage: f = z*w sage: my_eval(f,2) _5 = 2*z sage: g=(w+1)+w^2*z+3*z^3 sage: my_eval(g,2) _7 = 3*z^3 + 4*z + 3 HTH, Luis --~--~---------~--~----~------------~-------~--~----~ 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 URLs: http://sage.math.washington.edu/sage/ and http://sage.scipy.org/sage/ -~----------~----~----~----~------~----~------~--~---
