Hi, I tried python lists and every thing seems fine to me-
>>> ls=symbols('a:10') >>> ls (a0, a1, a2, a3, a4, a5, a6, a7, a8, a9) Now I call a function Sum (it sums up a series in particular, infinite series)- >>> for i in range(10): ... Sum(1/(ls[i]**ls[i]),(ls[i],1,oo)).evalf() ... 1.29128599706266 1.29128599706266 1.29128599706266 1.29128599706266 1.29128599706266 1.29128599706266 1.29128599706266 1.29128599706266 1.29128599706266 1.29128599706266 Also, >>> solve([ls[0]+5*ls[1]-2,-3*ls[0]+6*ls[1]-15]) {a0: -3, a1: 1} It might be that I have misunderstood your problem :( On Sat, Dec 1, 2012 at 7:13 PM, Matthew Rocklin <mrock...@gmail.com> wrote: > I ran into this problem in MatrixExprs. We don't currently have a > subscripted symbol. It would be nice though. > > In the following example > In [1]: X = MatrixSymbol('X', n, n) > > In [2]: X[1, 2] > Out[2]: X₁₂ > > Ideally X[1, 2] is a Symbol that contains separate information for its > origin X and its indices, 1, and 2. Alas, all it knows is the combined > string "X_12". > > > > > On Sat, Dec 1, 2012 at 7:30 AM, Shriramana Sharma <samj...@gmail.com>wrote: > >> On Sat, Dec 1, 2012 at 6:46 PM, Chris Smith <smi...@gmail.com> wrote: >> > >> > that's what symbols does for you; just store the result in an array if >> you >> > want: >> > >> >>>> a=symbols('a:11') >> >>>> a[1] >> > a1 >> >>>> a >> > (a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10) >> >> But I already said that I can't use a Python list because I can't then >> use something like a[i] as part of an expression where i is a symbol. >> For example summation(a[i],(i,0,n)) would throw an IndexError or >> something saying that the index of a list has to be an integer. The >> SymList or something that I visualize should be able to handle the >> above. >> >> > Have you looked at Indexed? >> >> Hey nice, but still I have this problem: >> >> from sympy import IndexedBase >> A=IndexedBase('A') >> solve([A[0] + 5*A[1] - 2, -3*A[0]+ 6*A[1] - 15]) >> >> produces at the end of the source trace: >> >> AttributeError: 'int' object has no attribute 'free_symbols' >> >> The subscriptable symbol which I expect should be able to handle the >> above solve command. Or if I have to alter my usage slightly (i.e. >> without using all that atoms etc) for IndexedBase itself (or some >> existing subclass thereof) to be able to handle the above solve, >> please indicate it. Thanks! >> >> -- >> Shriramana Sharma >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sympy" group. >> To post to this group, send email to sympy@googlegroups.com. >> To unsubscribe from this group, send email to >> sympy+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/sympy?hl=en. >> >> > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to sympy@googlegroups.com. > To unsubscribe from this group, send email to > sympy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > -- Regards, Rishabh Dixit BITS Pilani -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.