Re: fastest way to add up a billion numbers

*To*: mathgroup at smc.vnet.net*Subject*: [mg73907] Re: fastest way to add up a billion numbers*From*: "dimitris" <dimmechan at yahoo.com>*Date*: Sat, 3 Mar 2007 00:55:02 -0500 (EST)*References*: <es92b2$3oj$1@smc.vnet.net>

There is recent post of mine asking something relevant here. You can find also a relevant thread here: http://forums.wolfram.com/mathgroup/archive/2005/May/msg00600.html One billion numbers? Here is what I get to my PC In[3]:= Range[10^9] >From In[3]:= No more memory available. Mathematica kernel has shut down. Try quitting other applications and then retry. In[1]:= Table[i, {i, 1, 10^9}]; >From In[1]:= No more memory available. Mathematica kernel has shut down. Try quitting other applications and then retry. Anyway... lst = Range[10^6]; Timing[Plus @@ lst] {0.34299999999999997*Second, 500000500000} Timing[Total[lst]] {0.2659999999999999*Second, 500000500000} Timing[Fold[Plus, 0, lst]] {0.703*Second, 500000500000} Timing[lst /. {x_, y___} -> x + y] {0.45300000000000007*Second, 500000500000} Timing[Tr[lst]] {0.3899999999999997*Second, 500000500000} Timing[Sum[lst[[i]], {i, 1, 10^6}]] {1.4379999999999997*Second, 500000500000} But for your case I should simply suggest Timing[Sum[i,{i,1,10^9}]] {0.047 Second,500000000500000000} Regards Dimitris =CF/=C7 Raj =DD=E3=F1=E1=F8=E5: > hi! > > Could somebody tell me what would be the fastest way to add up a > billion numbers(from 1 to 10^9 i.e the first billion numbers) in > Mathematica? > > Ofcourse the answer is n(n+1)/2, but is there any other way in > Mathematica other than the following one: > > Total@@Range[10^9] > > Thanks, > > Raj

**Follow-Ups**:**Re: Re: fastest way to add up a billion numbers***From:*Devendra Kapadia <dkapadia@wolfram.com>

**Re: fastest way to add up a billion numbers***From:*"Raj" <rajanikanth@gmail.com>

**Re: Re: fastest way to add up a billion numbers***From:*Murray Eisenberg <murray@math.umass.edu>