       Re: color legend

• To: mathgroup at smc.vnet.net
• Subject: [mg110498] Re: color legend
• From: Bob Hanlon <hanlonr at cox.net>
• Date: Mon, 21 Jun 2010 02:11:41 -0400 (EDT)
• Reply-to: hanlonr at cox.net

```It you want it to do more, just tell it so.

Needs["PlotLegends`"]

arrayPlot[expr_, iterX_, iterY_] :=
Module[
{x = iterX[], y = iterY[],
min, max, cons},
cons = LessEqual @@ (#[[{2, 1, 3}]]) & /@
{iterX, iterY};
min = ToString[Round[
NMinimize[{expr, cons},
{x, y}][] // Chop, 0.1]];
max = ToString[Round[
NMaximize[{expr, cons},
{x, y}][] // Chop, 0.1]];
ShowLegend[
ArrayPlot[
Table[5./(1 + x^2 + y^2),
iterX, iterY],
Frame -> None,
ColorFunction ->
Function[{a},
RGBColor[1 - a, 1 - a, 1 - a]]],
{Function[{a},
RGBColor[a, a, a]], 11, max, min,
LegendPosition -> {1.1, -0.4}}]]

m = RandomInteger[{5, 25}]

10

arrayPlot[m/(1 + x^2 + y^2),
{x, -5, 5}, {y, -5, 5}]

Bob Hanlon

---- "Kevin J. McCann" <kjm at KevinMcCann.com> wrote:

=============
Bob,

The problem I have with this approach is that you have to give, in text,
the min and max labels for the plot. This is clearly a place where
errors can occur. It would be really great if all you had to do was to
specify the min and max of the z-axis (color scale) and the legend
automatically incorporated this.

Kevin

Bob Hanlon wrote:
> Needs["PlotLegends`"]
>
> ShowLegend[
>  ArrayPlot[
>   Table[5./(1 + x^2 + y^2),
>    {x, -5, 5}, {y, -5, 5}],
>   Frame -> None,
>   ColorFunction ->
>    Function[{a},
>     RGBColor[1 - a, 1 - a, 1 - a]]],
>  {Function[{a},
>    RGBColor[a, a, a]],
>   11, " 5", " 0",
>   LegendPosition -> {1.1, -0.4}}]
>
>
> Bob Hanlon
>
> ---- eric g <eric.phys at gmail.com> wrote:
>
> =============
> Hello Group,
> I want to add a color grayscale
> (myColorFunction[x_]:=RGBColor[1-x,1-x,1-x]) legend this arrayplot, from
> min (white) to max (dark) values.
>
> ArrayPlot[Table[5./(1 + x^2 + y^2), {x, -5, 5}, {y, -5, 5}], Frame -> None]
>
> best regards,
> eric
>

```

• Prev by Date: Re: Floating point exception when taking a reciprocal
• Next by Date: Re: whats wrong with this code ?!
• Previous by thread: Re: color legend
• Next by thread: defining a function of functions