Re: How to Multiply a Sequence of #s that depends on the previous #

*To*: mathgroup at smc.vnet.net*Subject*: [mg125139] Re: How to Multiply a Sequence of #s that depends on the previous #*From*: Dana DeLouis <dana01 at me.com>*Date*: Thu, 23 Feb 2012 05:49:52 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

On Feb 21, 6:18 am, Bill Rowe <readn... at sbcglobal.net> wrote: > On 2/20/12 at 2:46 AM, clutchderivat... at gmail.com (Clutch) wrote: > Out[3]= {50,55.,63.25,75.9,102.465} > and to show each subsequent value in lst has the correct ratio > In[4]:= 1/Divide @@@ Partition[lst, 2, 1] > Out[4]= {1.1,1.15,1.2,1.35} Hi. Just to mention another way to check... lst = {50,55.,63.25,75.9,102.465} ; Ratios[lst] {1.1, 1.15, 1.2, 1.35} = = = = = = = = = = = = HTH :> ) Dana DeLouis Mac & Math 8 = = = = = = = = = = = = On Feb 21, 6:18 am, Bill Rowe <readn... at sbcglobal.net> wrote: > On 2/20/12 at 2:46 AM, clutchderivat... at gmail.com (Clutch) wrote: > > >I have a list of #s : 1.10, 1.15, 1.20, 1.35. > >I start off with 50 and the first # is 50 * 1.10. > >The second # is the first # * 1.15. > >The third # is the second # * 1.20. > >The fourth # is the third # * 1.35. > >I want to maintain a list of these #s. How can this be done > >efficiently in Mathematica without running for loops? > > If I understand correctly, you can do this by: > > In[3]:= lst = FoldList[Times, 50, {1.1, 1.15, 1.2, 1.35}] > > Out[3]= {50,55.,63.25,75.9,102.465} > > and to show each subsequent value in lst has the correct ratio > > In[4]:= 1/Divide @@@ Partition[lst, 2, 1] > > Out[4]= {1.1,1.15,1.2,1.35}