Re: Apply function to parts of a list

*To*: mathgroup at smc.vnet.net*Subject*: [mg86255] Re: Apply function to parts of a list*From*: Peter Breitfeld <phbrf at t-online.de>*Date*: Fri, 7 Mar 2008 02:26:14 -0500 (EST)*References*: <fqo8pn$svq$1@smc.vnet.net>

guerom00 schrieb: > Hi all, > > Very often, I find myself having datas to plot of this form : > > data={{x1,y1},{x2,y2},{x3,y3}...{xn,yn}} > > So, very conventional : a list of abscissa and ordinate. Now, let's say I want to multiply by 2 all my ascissa. Right now, I write : > > MapAt[2*#&,data,Table[{i,1},{i,1,Length[data]}]] > > It's OK but I isn't there another way to achieve this as I find this rather "involved" for such a simple thing ? > > Thanks in advance. > One possibility is {2#[[1]],#[[2]]}&/@data or with a rule: data/.{x_,y_}->{2x,y} Gruss Peter -- ==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-== Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de