Re: Substitution!!!

*To*: mathgroup at smc.vnet.net*Subject*: [mg35679] Re: [mg35660] Substitution!!!*From*: Tomas Garza <tgarza01 at prodigy.net.mx>*Date*: Thu, 25 Jul 2002 04:46:29 -0400 (EDT)*References*: <200207240607.CAA28759@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

To start with, you have only 13 *and not 14* polynomials. I would suggest you make a straightforward assignment, such as In[1]:= Clear[s]; s = {1 + x, 1 + x + x^2, 1 + x + x^3, 1 + x^2 + x^3, 1 + x + x^6, 1 + x^3 + x^6, 1 + x + x^2 + x^4 + x^6, 1 + x + x^3 + x^4 + x^6, 1 + x^5 + x^6, 1 + x + x^2 + x^5 + x^6, 1 + x^2 + x^3 + x^5 + x^6, 1 + x + x^4 + x^5 + x^6, 1 + x^2 + x^4 + x^5 + x^6}; Here you check that there are only 13: In[2]:= Length[s] Out[2]= 13 so that, for example, In[3]:= s[[1]] Out[3]= 1 + x Then, you get In[4]:= Product[s[[i]], {i, 1, 8}] Out[4]= (1 + x)*(1 + x + x^2)*(1 + x + x^3)*(1 + x^2 + x^3)* (1 + x + x^6)*(1 + x^3 + x^6)*(1 + x + x^2 + x^4 + x^6)* (1 + x + x^3 + x^4 + x^6) as desired. You could benefit enormously by using a proper notation and display form. Define In[5]:= Subscript[s_, n_] := s[[n]] and display this cell (and other cells, too) as standard form (select the cell or cells, and then Cell | Convert To | Standard Form). You'll see your formulas displayed very nicely. It is easy to write Subscript[s, n] by typing s, then Ctrl - (i.e., Ctrl key and then minus sign) and then n. Tomas Garza Mexico City ----- Original Message ----- From: "Chekad Sarami" <csarami at mtu.edu> To: mathgroup at smc.vnet.net Subject: [mg35679] [mg35660] Substitution!!! > Hi, > > > I have a question regarding substitute of an expression with index > variables..I need to make a table for some products of irreducible > polynomials (Irreducible factors of x^63 -1) . But they are so large and I > can't fit them into the columns of my table. So I need to use these > substitutions > > {S_1, S_2, S_3, S_4, S_5, S_6, S_7, S_8, S_9, S_10, S_11, S_12, S_13, S_14} > : ------> {1 + x, 1 + x + x^2, 1 + x + x^3, 1 + x^2 + x^3, 1 + x + x^6, > 1 + x^3 + x^6, 1 + x + x^2 + x^4 + x^6, 1 + x + x^3 + x^4 + x^6, 1 + > x^5 + x^6, 1 + x + x^2 + x^5 + x^6, 1 + x^2 + x^3 + x^5 + x^6, 1 + x + x^4 > + x^5 + x^6, 1 + x^2 + x^4 + x^5 + x^6} > > > > ***** The right side is a list of irreducible polynomials which is assigned > to {S_1, S_2,.... S_14}.******* > > > > For example instead of putting this large expression (1 + x) (1 + x + x^2) > (1 + x + x^3) (1 + x + x^6) (1 + x^3 + x^6) (1 + x + x^2 + x^4 + x\^6) (1 + > x + x^3 + x^4 + x^6) (1 + x + x^2 + x^5 + x^6) in my table I can write it in > tems of S_i's in this form S_1 S_2 S_3 S_4 S_5 S_6 S_7 S_8. > > > > I tried ReplaceAll but it changes i.e. the above example to S_1 (S_1+x^3) > (S_1+x_6) .... Which is not what I want. > > Can anybody tell me how to do this. > > > > > > Regards > > CHEKAD > > > >

**References**:**Substitution!!!***From:*"Chekad Sarami" <csarami@mtu.edu>