title: android -- how to use achartengine -steps
body: <p>I am new to android,to java and of course to achartengine. 
   I have complete an application where the user enters some data and i 
   want with these data to make a line plot. 
   What are the steps i must follow? </p>
  
  <ol>
  <li>Import the achartengine jar file. </li>
  <li>Use the abstractdemochart.class file in my application. </li>
  <li>Use the trigonometricfunctionschart file in my application. </li>
  <li>Edit the  trigonometricfunctionschart file  in order to use my 
  data. </li>
  </ol>
  
  <p>I don't know if the above are correct.Also,if i must edit 
   trigonometricfunctionschart file,how can i handle my variables (data) 
   that are in the number_cores.class? </p>
  
  <p>Here is the number_cores.class which does the calculations. 
   User enters the num_cores,halftime and timecores (time). </p>
  
  <p>I want to do a plot with time vs fcores( number of cores below from 
   the cores_func). </p>
  
  <p>(And what if i want time to be from 0 to the time which the user enters.)</p>
  
  <pre><code>public class number_cores extends Activity implements OnClickListener 
   { 
           EditText num_cores; 
           EditText halftimecores; 
           EditText timecores; 
           View core_calcs; 
  
           /** Called when the activity is first created. */ 
       @Override 
       public void onCreate(Bundle savedInstanceState) { 
  
          super.onCreate(savedInstanceState); 
           setContentView(R.layout.numbercores); 
  
          num_cores=(EditText) findViewById(R.id.num_cores); 
           halftimecores=(EditText) findViewById(R.id.halftimecores); 
           timecores=(EditText) findViewById(R.id.timecores); 
           core_calcs=(View) findViewById(R.id.core_calcs); 
           core_calcs.setOnClickListener(this); 
  
      } 
  
          public void onClick(View v) { 
                   switch (v.getId()){ 
                   case R.id.core_calcs: 
                           if(isNumeric(num_cores.getText().toString()) &amp;&amp; 
   isNumeric(halftimecores.getText().toString()) &amp;&amp; 
   isNumeric(timecores.getText().toString())) 
                   { 
                                   cores_func(); 
                   } 
                   else 
                   { 
                       Toast.makeText(number_cores.this, "Please provide 
   a number", Toast.LENGTH_SHORT).show(); 
                   } 
                   break; 
       } 
           } 
  
          public static boolean isNumeric(String str) 
           { 
             try 
             { 
               double d = Double.parseDouble(str); 
             } 
             catch(NumberFormatException nfe) 
             { 
               return false; 
             } 
             return true; 
           } 
           public void cores_func(){ 
                double 
   initcores=Double.parseDouble(num_cores.getText().toString().trim()); 
                double 
   half_time=Double.parseDouble(halftimecores.getText().toString().trim()); 
                double 
   ttime=Double.parseDouble(timecores.getText().toString().trim()); 
                    double l=Math.log(2)/half_time; 
                double fcores=initcores*Math.exp(-l*ttime); 
  
               Intent i=new Intent(this,core_calcs.class); 
                    i.putExtra("value",fcores); 
                startActivity(i); 
            }
  </code></pre>
  
  <p>Thank you!</p>