Android : Achartengine chart switch in Layout

I'm trying to implement a code where i can switch charts with dialog. My charts are dynamic charts and i use thread to fill up them with data (random numbers). I will have 3 type of chart: point, bar, and linechart. First of all i need to figure out how to switch charts. In the onCreate method i start a line chart and it works. Now if i try to clear the Layout and start the chart again it fails. I dont't know the sollution. I paste here the original code.

public class ChartActivity extends Activity {

private GraphicalView view;

Thread thread;

private TimeSeries dataset = new TimeSeries("");
private XYMultipleSeriesDataset mDataset = new XYMultipleSeriesDataset();

private XYSeriesRenderer renderer = new XYSeriesRenderer();
private XYMultipleSeriesRenderer mRenderer = new XYMultipleSeriesRenderer();

private CharSequence [] dialog_list = {"Line chart", "Bar chart", "Point chart"};

private LinearLayout layout;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_chart);

    layout = (LinearLayout) findViewById(R.id.chart);

    Graph();

    Button switchButton = (Button) findViewById(R.id.switchChart);

    switchButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ChartActivity.this.showDialog(1);
        }
    });
}

@Override
protected Dialog onCreateDialog(int id) {
    Dialog dialog;

    switch(id){
    default:
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Choose option:").setItems(dialog_list, new 
        DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {

            //TODO

            }
        });

        dialog = builder.create();

        break;
    }

    return dialog;
}

public void Graph(){
    thread = new Thread(new Runnable(){
        public void run(){
            for(int i=0;i<1000;i++){
                Random random = new Random();
                try{
                    Thread.sleep(1000);
                }catch(InterruptedException e){
                    e.printStackTrace();
                }

                double randomNumber = random.nextInt(10);                   

                dataset.add((double) i, randomNumber);

                mRenderer.setXAxisMin(i-10);
                mRenderer.setXAxisMax(-Double.MAX_VALUE);
                mRenderer.setYAxisMax(20);
                mRenderer.setYAxisMin(-10);

                view.repaint();
            }
        }
    }, "thread");
    thread.start();

    mDataset.addSeries(dataset);

    mRenderer.addSeriesRenderer(renderer);
}


@Override
protected void onResume() {
      super.onResume();

      if (view == null) {
        //LinearLayout layout = (LinearLayout) findViewById(R.id.chart);

        view = ChartFactory.getLineChartView(this, mDataset, mRenderer);

        layout.addView(view);
      } else {
        view.repaint();
      }
 }
}

And here is my layout:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#F6F6F6" >

<LinearLayout
    android:id="@+id/chart"
    android:layout_width="380dp"
    android:layout_height="300dp"
    android:layout_alignLeft="@+id/switchChart"
    android:layout_alignParentTop="true"
    android:layout_alignRight="@+id/backButton"
    android:layout_marginTop="30dp"
    android:orientation="vertical" >

    </LinearLayout>
</RelativeLayout>

All in all, how can i switch charts in my code, included deleting Layout, stop thread if necessary or a new function.

Thanks