Re: functional routine for {a, b, c, ...} -> {a - b, b - c, c - ...a}

*To*: mathgroup at smc.vnet.net*Subject*: [mg24907] Re: [mg24892] functional routine for {a, b, c, ...} -> {a - b, b - c, c - ...a}*From*: Andrzej Kozlowski <andrzej at tuins.ac.jp>*Date*: Sun, 20 Aug 2000 01:34:56 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I see nothing wrong with using ListCorrelate but here is another way: In[4]:= Drop[lst - RotateLeft[lst], -1] Out[4]= {a - b, b - c, c - d, d - e, e - f, f - g, g - h} Andrzej on 8/19/00 10:46 AM, Maarten.vanderBurgt at icos.be at Maarten.vanderBurgt at icos.be wrote: > Hallo, > > element. > I found two ways for doing this: > > lst = {a, b, c, d, e, f, g, h}; > > Table[lst[[i]] - lst[[i + 1]], {i, 1, Length[lst] - 1}] > {a - b, b - c, c - d, d - e, e - f, f - g, g - h} > > ListCorrelate[{1, -1}, lst] > {a - b, b - c, c - d, d - e, e - f, f - g, g - h} > > The first method is rather clumsy and the 2nd one is quite short, but not > really obvious. > Initally I was looking for a functional programming style routine. > Something like: (#[[i]]-#[[i-1]])&/@lst. > Who can tell me how to do this in a functional programming style? > > Thanks > > Maarten van der Burgt > Leuven, Belgium > > > >