Re: Coloring curves: not as simple as it sounds..
- To: mathgroup at smc.vnet.net
- Subject: [mg118157] Re: Coloring curves: not as simple as it sounds..
- From: Chris Rodgers <see-rodgers-org-uk-for-contact-details at invalid.gg>
- Date: Thu, 14 Apr 2011 07:08:43 -0400 (EDT)
- References: <io6d17$dpl$1@smc.vnet.net>
Not a full explanation, but try this: Plot[Evaluate[{a x, a x^2, a x^3} /. {a -> 1}], {x, 0, 2}, PlotStyle -> {Red, Green, Blue}] That works for me. Now run Attributes[Plot] So, the issue is to do with the HoldAll attribute on Plot. I guess when Plot counts the number of lines it is expecting to produce, it doesn't untangle your rule replacement. C. On 14/04/2011 09:59, 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!!! >