title: GraphView, how to show x-axis label?
body: <p>I'm trying to plot graph using GraphView library. My problem is, the x-axis does not show up but the y-axis can. Besides, the value at the x-axis label also not showing up. </p>
  
  <p>Here is my xml file:</p>
  
  <pre><code>    &lt;com.jjoe64.graphview.GraphView
          android:id="@+id/graph"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:layout_alignParentBottom="true"
          android:layout_alignParentTop="true"
          android:background="#FAFA82" /&gt;
  </code></pre>
  
  <p>and the java code:</p>
  
  <pre><code>double graph1LastXValue = 5d;
  GraphView graph = (GraphView) findViewById(R.id.graph);
  graph.getGridLabelRenderer().setVerticalAxisTitle("Match Value");
  graph.getGridLabelRenderer().setHorizontalAxisTitle("Time/s");
  Series2 = new LineGraphSeries&lt;DataPoint&gt;();
  mSeries1.setColor(Color.RED);
  mSeries1.setThickness(2);
  graph.addSeries(mSeries2);
  graph.getViewport().setXAxisBoundsManual(true);
  graph.getViewport().setMinX(0);
  graph.getViewport().setMaxX(100);
  graph.getGridLabelRenderer().setGridStyle(GridStyle.BOTH);
  plotter(matchValMean);
  
  protected void plotter(Double matchVal) {
  matchValue = matchVal;
  // TODO Auto-generated method stub
  mTimer1 = new Runnable() {
      @Override
       public void run() {
              graph1LastXValue += 1d;
              mSeries1.appendData(new DataPoint(graph1LastXValue, matchValue), true, 100);
              mHandler.postDelayed(this, 1000);
          }
      };
      mHandler.postDelayed(mTimer1, 1000);
  }
  </code></pre>
  
  <p>I did not show all the codes because it is very long. Thanks in advance :)</p>