Re: Replacing Parts of a List

*To*: mathgroup at smc.vnet.net*Subject*: [mg28757] Re: [mg28742] Replacing Parts of a List*From*: Andrzej Kozlowski <andrzej at tuins.ac.jp>*Date*: Fri, 11 May 2001 20:00:35 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I am not sure if I understand you correctly. The way I see it the situation is exactly the same with Subscript as it is with List. Compare: In[1]:= l={a,b};l[[2]]=3;l Out[1]= {a, 3} In[2]:= Clear[l] In[3]:= l=Subscript[a,b];l[[2]]=3;l Out[3]= a 3 Same behaviour. Equally, neither {a, b}[[2]] = 3 nor Subscript[a,b][[2]]=3 will work and for the same reason. Perhaps I have missed your point? Could you be more explicit? -- Andrzej Kozlowski Toyama International University JAPAN http://platon.c.u-tokyo.ac.jp/andrzej/ http://sigma.tuins.ac.jp/~andrzej/ on 01.5.11 4:38 PM, Roger Jones at rmj at SLAC.Stanford.EDU wrote: > Given x={1,2} then setting part 1 to 10 (say) is done via x[[1]]=10. > This > appealing as it is a condensed notation and is I believe, very > efficient for large > arrays. > > However, with a subscripted symbol (such as Subscript[x,y]) how is it > done? > > It can be achieved with Subscript[x,y]=ReplacePart[Subscript[x,y],10,1] > but this is a little unwieldy. > > Is there some method (using Hold[Subscript[x,y]] or something like this) > > that allows a direct replacement? > > Thank you! > > -Roger Jones > > > > >