Re: novice needs help using Manipulate with Plot
- To: mathgroup at smc.vnet.net
- Subject: [mg78466] Re: novice needs help using Manipulate with Plot
- From: dh <dh at metrohm.ch>
- Date: Mon, 2 Jul 2007 06:55:45 -0400 (EDT)
- References: <f68458$eoh$1@smc.vnet.net>
Hi,
Manipulate localizes the variable m. It is then different from the
global variable m. Therefore, if you do not want to define your function
inside Manipulate, you must replace the variable of your function by the
variable of Manipulate. This can be done e.g. by a parameter as you
already found or by a replacement rule:
test:=mm x
Manipulate[Plot[Evaluate[test/.mm->m],{x,0,10}],{{m,1},0,2}]
The Evaluate is there for efficiency.
hope this helps, Daniel
PHILLMAN5 at gmail.com wrote:
> Manipulate seems at first to be very powerful, but I am having trouble
> using it with my own functions. To vastly simplify my problem say I
> want to plot y = m x, with x going from 0 to 10, with the slider in
> Manipulate controlling m. I have tried the following:
>
> test := m x
> Manipulate[Plot[test, {x, 0, 10}], {{m, 1}, 0, 2}]
>
> test3[x_] := m x;
> Manipulate[Plot[test3[x], {x, 0, 10}], {{m, 1}, 0, 2}]
>
> don't seem to work. If you define the function with m as a formal
> parameter, like the following it does.
>
> test2 = #1 #2 &;
> Manipulate[Plot[test2[m , x], {x, 0, 10}], {{m, 1}, 0, 2}]
>
> test4[m_, x_] := m x;
> Manipulate[Plot[test4[m, x], {x, 0, 10}], {{m, 1}, 0, 2}]
>
> Is there anyway to write functions to work with Manipulate without
> have to have all the slider(s) formally written as a parameter to the
> function?
>
>