title: Jasper iReports charts changing Label Expressions
body: <p>I am using Jasper iReport to create an .xrml file to create a Jasper report. My file has a 3-D bar chart with multiple series - this is keyed on group_id. I want the label to be "Group "+ group_id. I tried to set this in the Chart details->Data-> Category series tab, but it did not work.The .xrml file directly looks like</p>
  
  <pre><code>&lt;labelExpression&gt;&lt;![CDATA["Group "+$F{group_id} +"sdf"]]&gt;&lt;/labelExpression&gt;
  </code></pre>
  
  <p>But this just shows 1,2,3 as labels. How can I append the word "Group" to the label please?</p>
  
  <p>Also I would like to create a label for the y-axis, currently it just shows numbers. How can I do that please?</p>
  
  <p>Attaching my .xrml file</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="simple_chart" language="groovy" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="30a6fcf0-fa89-4cf5-863d-403bf68304ef"&gt;
      &lt;property name="ireport.zoom" value="1.0"/&gt;
      &lt;property name="ireport.x" value="0"/&gt;
      &lt;property name="ireport.y" value="0"/&gt;
      &lt;queryString&gt;
          &lt;![CDATA[select count(person_id), name, group_id from group_events group by name, group_id]]&gt;
      &lt;/queryString&gt;
      &lt;field name="count" class="java.lang.Long"/&gt;
      &lt;field name="name" class="java.lang.String"/&gt;
      &lt;field name="group_id" class="java.lang.Integer"/&gt;
      &lt;background&gt;
          &lt;band splitType="Stretch"/&gt;
      &lt;/background&gt;
      &lt;title&gt;
          &lt;band height="32" splitType="Stretch"&gt;
              &lt;staticText&gt;
                  &lt;reportElement x="191" y="0" width="100" height="20" uuid="a4a09404-48bc-4895-9c33-b73fc139a67c"/&gt;
                  &lt;textElement&gt;
                      &lt;font size="14" isBold="true"/&gt;
                  &lt;/textElement&gt;
                  &lt;text&gt;&lt;![CDATA[names]]&gt;&lt;/text&gt;
              &lt;/staticText&gt;
          &lt;/band&gt;
      &lt;/title&gt;
      &lt;summary&gt;
          &lt;band height="383"&gt;
              &lt;bar3DChart&gt;
                  &lt;chart&gt;
                      &lt;reportElement x="30" y="16" width="515" height="298" uuid="3c938c8e-586f-4a0e-a0b7-3a188ed0fe4b"/&gt;
                      &lt;chartTitle/&gt;
                      &lt;chartSubtitle/&gt;
                      &lt;chartLegend/&gt;
                  &lt;/chart&gt;
                  &lt;categoryDataset&gt;
                      &lt;categorySeries&gt;
                          &lt;seriesExpression&gt;&lt;![CDATA[$F{group_id}]]&gt;&lt;/seriesExpression&gt;
                          &lt;categoryExpression&gt;&lt;![CDATA[$F{name}]]&gt;&lt;/categoryExpression&gt;
                          &lt;valueExpression&gt;&lt;![CDATA[$F{count}]]&gt;&lt;/valueExpression&gt;
                          &lt;labelExpression&gt;&lt;![CDATA["Group "+$F{group_id} + "sdf"]]&gt;&lt;/labelExpression&gt;
                      &lt;/categorySeries&gt;
                  &lt;/categoryDataset&gt;
                  &lt;bar3DPlot&gt;
                      &lt;plot/&gt;
                      &lt;itemLabel/&gt;
                      &lt;categoryAxisFormat&gt;
                          &lt;axisFormat/&gt;
                      &lt;/categoryAxisFormat&gt;
                      &lt;valueAxisFormat&gt;
                          &lt;axisFormat/&gt;
                      &lt;/valueAxisFormat&gt;
                  &lt;/bar3DPlot&gt;
              &lt;/bar3DChart&gt;
          &lt;/band&gt;
      &lt;/summary&gt;
  &lt;/jasperReport&gt;
  </code></pre>