
Re: Question about Manipulate
Posted:
Nov 10, 2011 6:28 AM


On Nov 9, 10:37 pm, "mail...@gmail.com" <mail...@gmail.com> wrote: > I tried the following code in Mathematica 8.0 > > Clear["Global`*"] > f = Sin[a x + b] > Manipulate[Plot[f, {x, 0, 4 \[Pi]}], {a, 0.5, 2}, {b, 0, 2 \[Pi]}] > > The Manipulate block is showed, but the Sin function is not plotted. > > When I replace f in the third line with its definition, > > Clear["Global`*"] > Manipulate[ Plot[Sin[a x + b], {x, 0, 4 \[Pi]}], {a, 0.5, 2}, {b, 0, 2 > \[Pi]}] > > The Sin function is plotted. > > Is this a bug or a limitation in Mathematica?
your a and b within the Manipulate are not the global a and b you have used outside of the manipulate in your definition of f. That is why it is failing. In this particular case the syntax styling gives a heads up that they are different beasts.
Mike

