Re: Little(?) problem: What is the formula ???
- To: mathgroup at smc.vnet.net
- Subject: [mg21941] Re: Little(?) problem: What is the formula ???
- From: Dr Dan <drdanw at my-deja.com>
- Date: Sat, 5 Feb 2000 00:49:16 -0500 (EST)
- References: <87e194$s01@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Here is the quick answer (Version 4 only): WeightedSum[s_] := Tr[Apply[Times, s, {1}]]; UnweightedSum[s_] := Tr[s[[All,2]]]; WeightedFraction[s_] := WeightedSum[s]/UnweightedSum[s]; In[35]:= serie2 = {{0.1, 100}, {0.12, 200}, {0.15, 300}}; WeightedFraction[serie2] Out[36]= 0.131667 Sorry I don't have time to go into why this works today, but here is a tip: In Mathematica, think in terms of "operations performed on a list" rather than "operations performed in a loop." In article <87e194$s01 at smc.vnet.net>, "Nijntje ?" <a.vanrossem at bellt-gca.nl> wrote: > Hello All ! > > I have two "series" of data : > The first serie are "normal values" > The seccond serie represents a percentage(Value) of an amount (Nominator) > > Serie 1) > Value Nominator > 100 1 > 150 1 > 125 1 > > Serie 2) > Value Nominator > 10 100 > 12 200 > 15 300 > > The Problem: > ---------------------------------------------------------------------- ---- > I want to find a GENERAL formula to calculate the SUM of these series, > So a formula which gives the following results > > Serie 1) 365 > Serie 2) 13,1 > > Explanation results: > Serie 1) 100+150+125 = 375 > > serie 2) 10% of 100 = 10 > 12% of 200 = 24 > 15% of 300 = 45 > So total amount = 600 and the fraction=79 so that is 13.1% > > What is the general formula (using value and nominator) ????????? > > Thank you very much !!! > > Sent via Deja.com http://www.deja.com/ Before you buy.