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RE: Legend on BarChart

• To: mathgroup at smc.vnet.net
• Subject: [mg81224] RE: [mg81185] Legend on BarChart
• From: "David Annetts" <davidannetts at aapt.net.au>
• Date: Sun, 16 Sep 2007 04:07:29 -0400 (EDT)
• References: <200709150806.EAA27996@smc.vnet.net>

Hi Tom,

> I'm using version 6 and would like to add a legend to a 
> BarChart.  I found the below example on this site. It works 
> but produces a raft of errors :

Not surprised -- both packages are legacy packages in 6.x ....

> 
> << Graphics`Legend`
> << Graphics`Graphics`
> ShowLegend[
>  BarChart[{1, -3, 4, 5, 2, 3}, {3, 6, 4,
>    3}], {{{Hue[0],
>     StyleForm["First", FontFamily -> "Times", FontSize -> 12,
>      FontWeight -> "Bold"]}, {Hue[0.6],
>     StyleForm["Second", FontFamily -> "Times", FontSize -> 12,
>      FontWeight -> "Bold"]}}, LegendPosition -> {1.1, -0.5}}]
> 
> Is there a better method to add a Legend to a BarChart in version 6 ?

That depends on what you mean by better ....

For me, it was easier to use appropriately-coloured text in an Epilog->{}
than to stuff around with the legend package.  

For your example, we want to load PlotLegends & BarCharts, then

Needs["PlotLegends`"]
Needs["Histograms`"]

ShowLegend[
 BarChart[{1, -3, 4, 5, 2, 3}, {3, 6, 4, 
   3}], {{{Hue[0], 
    StyleForm["First", FontFamily -> "Times", FontSize -> 12, 
     FontWeight -> "Bold"]}, {Hue[0.6], 
    StyleForm["Second", FontFamily -> "Times", FontSize -> 12, 
     FontWeight -> "Bold"]}}, LegendPosition -> {1.1, -0.5}}]

Produces a graph with a legend, but it's probably not what you were after.
You could remedy this using BarStyle

ShowLegend[
 BarChart[{1, -3, 4, 5, 2, 3}, {3, 6, 4, 3}, 
  BarStyle -> {Hue[0], Hue[0.6]}], {{{Hue[0], 
    StyleForm["First", FontFamily -> "Times", FontSize -> 12, 
     FontWeight -> "Bold"]}, {Hue[0.6], 
    StyleForm["Second", FontFamily -> "Times", FontSize -> 12, 
     FontWeight -> "Bold"]}}, LegendPosition -> {1.1, -0.5}}]

Now, only the legend looks disproportionately large, especially if you add a
title.  We can fix this by reducing the font size & the shadow.

ShowLegend[
 BarChart[{1, -3, 4, 5, 2, 3}, {3, 6, 4, 3}, 
  BarStyle -> {Hue[0], Hue[0.6]}, 
  PlotLabel -> 
   "Bar chart with legend"], {{{Hue[0], 
    StyleForm["First", FontFamily -> "Times", FontSize -> 10, 
     FontWeight -> "Bold"]}, {Hue[0.6], 
    StyleForm["Second", FontFamily -> "Times", FontSize -> 10, 
     FontWeight -> "Bold"]}}, LegendPosition -> {.8, -.54},
  LegendShadow -> .001}]

An alternative is to forget Legend & use an Epilog as in

border = Line[{{5.5, -.5}, {6.75, -.5}, {6.75, -2.5}, {5.5, -2.5}, \
{5.5, -.5}}]; BarChart[{1, -3, 4, 5, 2, 3}, {3, 6, 4, 3}, 
 BarStyle -> {Hue[0], Hue[0.6]}, 
 PlotLabel -> "Bar chart with legend",
 Epilog -> {
   Style[Text["First", {6.5, -1}, {1, 0}], 12, Hue[0], Bold],
   Style[Text["Second", {6.5, -2}, {1, 0}], 12, Hue[.6], Bold], 
   border}]

Regards,

Dave.

• References:
  • Legend on BarChart
    • From: tomfabtastic@hotmail.com