Re: fastest way to add up a billion numbers

*To*: mathgroup at smc.vnet.net*Subject*: [mg73950] Re: fastest way to add up a billion numbers*From*: Bill Rowe <readnewsciv at sbcglobal.net>*Date*: Sat, 3 Mar 2007 01:18:20 -0500 (EST)

On 3/2/07 at 6:41 AM, rajanikanth at gmail.com (Raj) wrote: >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] There are a great many ways. I suspect none is faster or more efficient than In[2]:= Timing[Sum[n, {n, 1, m}] /. m -> 10^9] Out[2]= {0.11082 Second,500000000500000000} Note for smaller lists of numbers it will be faster to actually sum a list, i.e., In[1]:= data=Range[10000]; Timing[Total@data] Timing[Sum[n,{n,1,m}]/.m\[Rule]10000] Out[2]= {0.000297 Second,50005000} Out[3]= {0.11049 Second,50005000} -- To reply via email subtract one hundred and four