Re: Length and Drop

*To*: mathgroup at smc.vnet.net*Subject*: [mg32203] Re: Length and Drop*From*: "Gerhard Neumann" <gneumann at gmx.net>*Date*: Sat, 5 Jan 2002 00:10:50 -0500 (EST)*Organization*: UTA Telekom AG*References*: <a13vdg$dgm$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi ! Mathematica is a mainly functional programming language and so its variables represent values, not states. In other words the function Drop doesn't change the value of timexp at all, it just returns the wanted value. So you have to write: timexp = Drop[timeexp,1] mfG Gerhard Neumann "Steve Gray" <stevebg at adelphia.net> schrieb im Newsbeitrag news:a13vdg$dgm$1 at smc.vnet.net... > The following sequence seems wrong to me, in that > after dropping some elements from a list, its Length is > still the same. I copied this directly from the notebook > but removed the In[] and Out[] statements. > > > timexp={{0,0}} -> {{0,0}} [this is ok] > > timexp=Append[timexp,{7,8}] -> {{0,0},{7,8}} [this is ok] > > Length[timexp] -> 2 [this is ok] > > Drop[timexp,1] -> {{7,8}} [this is ok] > > Length[timexp] -> 2 [ this is what I did not expect!] > > Should not Drop reduce the Length of the list by the amount > dropped? > >