Re: help for time series basic operations

*To*: mathgroup at smc.vnet.net*Subject*: [mg46062] Re: [mg46046] help for time series basic operations*From*: Yasvir Tesiram <tesiramy at omrf.ouhsc.edu>*Date*: Wed, 4 Feb 2004 02:29:31 -0500 (EST)*References*: <200402032320.SAA28930@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, Here is one way, Out[16]= {a1, a2, a3, a4, a5, a6, a7} In[17]:= Table[a[[i+1]]-a[[i]], {i,1,Length[a]-1, 1}] Out[17]= {-a1 + a2, -a2 + a3, -a3 + a4, -a4 + a5, -a5 + a6, -a6 + a7} NB. Avoid using the underscore character on the right hand side for naming of variables. The underscore character has special meaning in Mathematica. Ciao On Tue, 3 Feb 2004, paolo wrote: > I am a quantitative analyst and for the first time i am using Mathematica. So, I > am sorry if my question seem "very easy (almost stupid)" but i need some helps > to begin to understand Mathematica > > I have a time series > a:=[a_1,a_2,a_3,a_4,...a_n] > how can i do to subtract each element for the previous one?: > > b:=[a_2 - a_1, a_3 - a_2, a_4 - a_3,.....,a_n - a_n-1] > > Thanks > > Paolo Tarpanelli >

**References**:**help for time series basic operations***From:*"paolo" <tarpanelli@libero.it>