Re: Coloring curves: not as simple as it sounds..
- To: mathgroup at smc.vnet.net
- Subject: [mg118165] Re: Coloring curves: not as simple as it sounds..
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Fri, 15 Apr 2011 03:55:16 -0400 (EDT)
This has been discussed before -- multiple times, probably, in this
list.Search the comp.soft-sys.math.mathematica archives for the "plot
colors".
In brief, the difference you get is because Plot has Attribute HoldAll.
The work-around is to wrap your table with Evaluate:
Plot[Evaluate[{a x, a x^2, a x^3} /. {a -> 1}], {x, 0, 2},
PlotStyle -> {Red, Green, Blue}]
On 4/14/2011 4:49 AM, Jean-Michel Di Nicola wrote:
> All,
>
> I have a question that looks fairly trivial, but I cannot solve it....
> Please help!
>
> Thanks, JM
>
> Here is a simplified toy example.
> When I type
> Plot[{a x /. {a -> 1}, a x^2 /. {a -> 1}, a x^3 /. {a -> 1}}, {x, 0,
> 2}, PlotStyle -> {Red, Green, Blue}]
> I get 3 curves with different colors.
>
> Well, when I type
> Plot[{a x, a x^2, a x^3} /. {a -> 1}, {x, 0, 2},
> PlotStyle -> {Red, Green, Blue}]
> I get 3 curves but they are all blue, WHY?
>
> However, when I evaluate {a x /. {a -> 1}, a x^2 /. {a -> 1}, a x^3 /.
> {a -> 1} and {a x, a x^2, a x^3} /. {a -> 1}, they both give the same
> result....{x, x^2, x^3}.
>
> Thank you for your help!!!
>
--
Murray Eisenberg murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2859 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305