Re: List argument

*To*: mathgroup at smc.vnet.net*Subject*: [mg36393] Re: List argument*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Wed, 4 Sep 2002 21:22:03 -0400 (EDT)*Organization*: Universitaet Leipzig*References*: <al4aqb$rc1$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de*Sender*: owner-wri-mathgroup at wolfram.com

Hi, Plot[ Evaluate[ Table[eq, {m, -30, 29}] ],{x, -50, 50} ] Plot[] has the attribute HoldAll and if you don't evaluate it, it can't find out, that a list of expressions should be plotted instead of a single expression. *And* you should avoid For[] loops. You don't need explicit loops in Mathematica. Regards Jens CeZaR wrote: > > Hi, > > I want to do these operations: > > eq = m x^2 + 2(m + 1)x + m + 2 > l = {} > For[i = -30, i < 30, i++, AppendTo[l, eq /. m -> i]] > Plot[l, {x, -50, 50}] > > but i get this error: > l is not a machine-size real number at x = -49.99999583333334 > > Can someone exaplain to me what i am doing wrong here?? > > Thanks! > > CeZaR