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Re: Just primitive ColorFunction


©erých Jakub schrieb:
> I think, that it must be something very simple, but I cannot find the
> solution....
>
> I need to fill the Plot so, that area above the axis will be red and area
> below the axis will be blue. I tried it in a such way:
>
> Plot[Sin[x], {x, 0, 4 Pi} ,
>  AxesOrigin -> {0, 0},
>  Axes -> {True, True},
>  PlotStyle -> Thick,
>  ColorFunction ->
>   If[Sin[x] >= 0, RGBColor[1, 0, 0], RGBColor[0, 0, 1]],
>  Filling -> Axis,
>  ImageSize -> {380, 280}]
>
> But Mathematica says, that If is not a valid Color.
>
> If I try it with Function (according to examples in ColorFunction help),
>
> ColorFunction ->
>  Function[x, If[Sin[x] >= 0, RGBColor[1, 0, 0], RGBColor[0, 0, 1]]],
>
> it is working, but the color of Filling is red allover the range.
>
> Thanks for any hint, how to achieve the +Red/-Blue filling.
>
> Jakub
>
>

Jakub,

for this particular example the following works:

Plot[Sin[x], {x, 0, 4 Pi}, AxesOrigin -> {0, 0}, Axes -> {True, True},
  PlotStyle -> Thick,
 Filling -> Axis, FillingStyle -> {Blue, Red},
 ImageSize -> {380, 280}]

Gruss Peter
-- 
==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==
Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de


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