android -- make calculations with input data (numeric) -- (show graphs?)
<p>I am starting to learn android and i have a few questions.
I have my main program as:</p>

<pre><code>public class Radiation_overflowActivity  extends Activity implements OnClickListener {

    EditText init_cores;
        View final_cores;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {


        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

    //Set up click listeners
    init_cores=(EditText) findViewById(R.id.init_cores);
    //init_cores.setOnClickListener(this);
    final_cores=(View) findViewById(R.id.final_cores);
    final_cores.setOnClickListener(this);

     }

    //called when a button is clicked
    public void onClick(View v) {

        switch (v.getId()){

        case R.id.final_cores:
            //int r = Integer.parseInt(init_cores.getText().toString().trim());
            double initcores=Double.parseDouble(init_cores.getText().toString().trim());
            double l=2,t=2;
            double fcores=initcores*Math.exp(-l*t);
            Intent i=new Intent(this,calcs.class);
            i.putExtra("value",fcores);
            startActivity(i);
            break;
         }

       }
      }
</code></pre>

<p>Also, my main.xml:</p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" &gt;

&lt;TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/initial_cores" /&gt;
&lt;EditText
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/init_cores"
    android:inputType="numberDecimal" /&gt;
&lt;Button
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/final_cores"
    android:text="@string/calculate" /&gt;
&lt;/LinearLayout&gt;
</code></pre>

<p>My calcs.java:</p>

<pre><code>public class calcs extends Activity{

    TextView calcs_final;

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.calcs);

        calcs_final=(TextView) findViewById(R.id.calcs_final);

        double f=getIntent().getExtras().getDouble("value");

        calcs_final.setText(Double.toString(f));


}

}
</code></pre>

<p>My calcs.xml:</p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" &gt;

    &lt;TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/calcs_final" 
        android:text="@string/result" /&gt;


&lt;/LinearLayout&gt;
</code></pre>

<p>I want to do this:</p>

<p>The user enters data into the edittext (init_cores) and then i want to make some calculations to compute the final_cores and show it to the user.</p>

<p>I have trouble for showing the results.I am  starting another activity (calcs.class and calcs.xml).
Where i must do the calculations?To the calcs.class?
Right now,the user enters a number ,presses the "Calculate" button and then it shows the text (from the strings.xml) "Number of cores"" ,but not the result.</p>

<p>Also, can i use the input from the data and from my calculations and make a plot?If you could give me some directions to this.</p>

<p>Finally,is my approach right?</p>

<p>Thank you!</p>
