Mathematica 9 is now available
Student Support Forum
-----
Student Support Forum: 'imax evaluation in Sum[...]' topicStudent Support Forum > General > Archives > "imax evaluation in Sum[...]"

Next Comment >Help | Reply To Topic
Author Comment/Response
David Dumas
07/20/99 06:06am

How can one have the upper limit of a sum re-evaluated to yield possible simplifications? It seems the upper limit is only evaluated further when the answer is a number that allows explicit evaluation of the sum.

To clarify,

ident[k_]:=k
Sum[f[i],{i,1,ident[k]}]//InputForm

gives

Sum[f[i],{i,1,ident[k]}]

BUT

ident[k_]:=5
Sum[f[i],{i,1,ident[k]}]//InputForm

gives

f[1]+f[2]+f[3]+f[4]+f[5]

I would like a way to obtain

Sum[f[i],{i,1,k}]

from the first sum above.

URL: ,

Subject (listing for 'imax evaluation in Sum[...]')
Author Date Posted
imax evaluation in Sum[...] David Dumas 07/20/99 06:06am
Re: imax evaluation in Sum[...] Forum Modera... 08/02/99 3:19pm
Next Comment >Help | Reply To Topic