Android : Draw a line continuously using Canvas in Android

I am using canvas to draw a line continuously. I will draw the line in relative layout. For static line, I done. But I don't know how to draw a line continuously as below figure. Could you suggest to me a algorithm to do it. Thank you so much. This is my code

//XML file
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <RelativeLayout
        android:id="@+id/canvas"
        android:layout_width="match_parent"
        android:layout_height="140dp"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:layout_weight="1"
        android:background="#d3d3d3" >
    </RelativeLayout>

</RelativeLayout>

This is my code for static line

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;
import android.widget.RelativeLayout;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(new HeartGraphView (this));
        setContentView(R.layout.activity_main);
        RelativeLayout relativeLayout=(RelativeLayout)findViewById(R.id.canvas);
        RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.FILL_PARENT); 
        HeartGraphView v = new HeartGraphView(this);
        v.setLayoutParams(lp);
        relativeLayout.addView(v);          
    }    
    public class HeartGraphView  extends View {
        public HeartGraphView (Context context) {
            super(context);
            // TODO Auto-generated constructor stub
        }    
        int[] dataX={10,30,60,90,120,150,180,210,240,270};
        int[]  dataY={5,20,90,140,0,0,-50,-140,-20,100};
        @Override 
        public void onDraw (Canvas canvas) {
            int w;
            int h;
            h=280;
            Paint paint = new Paint();
            paint.setColor(Color.RED);
            paint.setStrokeWidth(6);
            for (int i = 0; i < dataX.length - 1; i++) {
                canvas.drawLine(dataX[i], h/2-dataY[i], dataX[i+1], h/2-dataY[i+1],paint);

            }

        }
    }

}