Thanks for your reply Bruin. I hope the following code clarifies what I am looking for:
##--------------------------------------------------------------------------------------------------------------------------------------------- # n=10 F = GF(7) Rx=PolynomialRing(F,n,'x') X=Rx.gens() f= Rx.random_element() print(f) #If I want to evaluate f at specific variables say x0 = 1, x5 = 7, then I can easily do it as print(f(x0 = 1, x5 = 7)) #On the other hand, suppose I want to evaluate f at xi = a, xj = b, where 1<= i, j <= n vary. I want to have something like f(X[i] = 1, X[j] = 5) # and supply values of i, j as input parameters. Is this possible? # ##--------------------------------------------------------------------------------------------------------------------------------------------- For Example: I tried this: f(X[1] = 1, X[2] = 5) and got this error: File "<ipython-input-6-3b58a4eab255>", line 10 f(X[Integer(1)] = Integer(1), X[Integer(2)] = Integer(5)) ^ SyntaxError: keyword can't be an expression On Friday, April 29, 2022 at 9:25:48 PM UTC+5:30 Nils Bruin wrote: > Can you explain a little more about what does not work? When I try to > replicate your example, everything works as expected: > > sage: n=2 > ....: F = GF(7) > ....: Rx=PolynomialRing(F,n,'x') > ....: X=Rx.gens() > sage: f=X[0]+X[1] > sage: f(x0=1) > x1 + 1 > sage: f(x0=1,x1=1) > 2 > > Alternatively you can evaluate using positional arguments: in a polynomial > ring there is a clear implied order on the generators, so the following is > unambiguous (and accepted): > > sage: f(1,1) #gives values for x0 and x1 in order > 2 > On Friday, 29 April 2022 at 04:33:36 UTC-7 Ha wrote: > >> Hi, >> I need to create a polynomial ring with arbitrary number of variables [n] >> and >> at some point during computation should be able to substitute values >> for a subset of variables. I can use the following method to generate >> my ring: >> ##-------------------------------------------- >> n=2 >> F = GF(7) >> Rx=PolynomialRing(F,n,'x') >> X=Rx.gens() >> ##---------------------------------------------- >> But if I take an element f = x0+x1 then how to substitute values for x0 >> and x1? >> In general I could use f(x0 = 1, x1 = 1) but with above method this >> doesnot seem to work. >> >> Any help is highly appreciated.... >> > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/a706ed4d-96b2-4e17-9834-2fb3f7da68een%40googlegroups.com.
