Re: Array reference help please

*To*: mathgroup at smc.vnet.net*Subject*: [mg73315] Re: [mg73295] Array reference help please*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sun, 11 Feb 2007 01:17:43 -0500 (EST)*Reply-to*: hanlonr at cox.net

a=100; data=Table[Random[],{40},{2}]; Plot[Total[data[[All,1]]* (UnitStep[#]*Exp[-a*#]&/@ (t-data[[All,2]]))], {t,0,1}]; Bob Hanlon ---- rob <robIV at piovere.com> wrote: > I've managed to get this code working but I'm stumped on a > good way to refer to the entries in the data when plotting. > The only thing I can get to work is to refer to the first of > each pair as Part[data[[i]],1] and the second as > Part[data[[i]],2]. > > And more humiliating, the second one I have to spell out > twice. I tried all kinds of substitutions but failed. I know > you gurus here know how to make this code look better and > run more quickly. Thanks for your time. > > > > =C3=8E=C2=B1=100;(* decay parameter*) > > (* first parameter is pulse amplitude, second is time of > occurrence - later to follow Poisson *) > > data=Table[Random[],{40},{2}]; > > li=Length[data]; > > Plot[Sum[ > Part[data[[i]],1] UnitStep[t-Part[data[[i]],2]] > Exp[-=C3=8E=C2=B1 (t-Part[data[[i]],2])], {i,li} > ] > ,{t,0,1}] >