Re: question about evaluation and Manipulate

*To*: mathgroup at smc.vnet.net*Subject*: [mg78337] Re: question about evaluation and Manipulate*From*: "Steve Luttrell" <steve at _removemefirst_luttrell.org.uk>*Date*: Thu, 28 Jun 2007 06:27:22 -0400 (EDT)*References*: <f5vqp7$iqj$1@smc.vnet.net>

This does what you want: f[x_,a_]=a x; Manipulate[Plot[f[x,a],{x,0,1},PlotRange->{{0,1},{0,1}}],{{a,0.5,"a"},0,1}] Two points: 1. The variable a is localised inside Manipulate so you need to pass it as an argument to the function. 2. Use an explicit PlotRange to prevent the plot from adjusting its range as a is varied. Steve Luttrell West Malvern, UK "Yaroslav Bulatov" <yaroslavvb at gmail.com> wrote in message news:f5vqp7$iqj$1 at smc.vnet.net... > I'm trying to manipulate a plot where the plotted expression is a > symbol that should be evaluated before plotting. > > f[x_] = a x; > Manipulate[Plot[f[x], {x, 0, 1}], {a, 0, 1}] > > This doesn't work, presumably because Plot doesn't have access to the > value of "a" set by Manipulate. So I'd like to evaluate the first > argument Plot, but not Plot itself before Manipulate is executed, is > there a way to do this? > >