achartengine - can't figure how to use dates as x axis - the file I save is empty

Question

I have an activity where I take the input from edit text and store it in an list.

I also store in list the current date.

Then , I press the save button which saves the above.

The next day the user enter some data more and save and so on.

I want to make a plot with x-axis date format and y axis the values the user entered.

In one activity I have:

...
String filename = "data.csv";    
List<Double> mydata=new ArrayList<Double>();
List<Date> mydate=new ArrayList<Date>();

....value=(EditText) findViewById(R.id.enter_data);
...
switch (v.getId()){
        case R.id.savebtn:
            savefunc();

            break;
        case R.id.graphicsbtn: 

            Intent i = new Intent();        
            i.setClassName(this,LineGraph.class.getName());                 
            this.startActivity(i);  
            break;

   public void savefunc(){

    SimpleDateFormat thedate = new SimpleDateFormat("dd/MM/yyyy"); 
    Date d=new Date();
    try{
     d=thedate.parse(filename);
    mydate.add(d);
    }
    catch  (ParseException e){
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    double thedata=Double.parseDouble(value.getText().toString().trim());
    mydata.add(thedata);
..
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(fos));
    for (int i=0;i<mydate.size();i++){
       bw.write(mydate.get(i)+","+mydata.get(i)+"\n");
   ...

In the LineGraph Activity:

public class LineGraph extends Activity {


    private static List<Date> date = new ArrayList<Date>();
private static List<Double> data = new ArrayList<Double>();

    public Intent getIntent(Context context){

           readfunc();

      TimeSeries series = new TimeSeries("Showing data");
    for (int i=0;i<date.size();i++){    
        series.add(date.get(i),data.get(i));    

    }

The read function:

public void readfunc(){

    SimpleDateFormat thedate = new SimpleDateFormat("dd/MM/yyyy"); 
    Date d=new Date();
    try{
     d=thedate.parse(filename);
    }
    catch.. 
    BufferedReader br = new BufferedReader(new InputStreamReader(fis));

         do {
             s = br.readLine();     
             if (s != null ){
                 String[] splitLine = s.split(",");
                 date.add(d);//Double.parseDouble(splitLine[0]));
                 data.add(Double.parseDouble(splitLine[1]));

I have these problems:

1) The file I receive is empty (some problem with the Date because the method for saving and reading from a file works).

2) At the graph screen appears a white background (of course no data because the file is empty) ,but why white background?I use the same code for other purposes and I don't receive a whitebackground.

3) I am not sure how to use Dates in x axis.Should I use List ? List ? .

------------------------UPDATE---------------------------------------------------------

Ok ,finally!(After user 'Dan' suggestion)

I used ChartFactory.getTimeChartView(this, dataset, mRenderer,"dd/MM/yyyy");

instead of ChartFactory.getLineChartIntent(context, dataset, mRenderer,"dd/MM/yyyy");

and you don't need to use String List , just Date List

score 2 · Accepted Answer · answered Apr 16 '13 at 22:21

2

The code that deal with your file must be something like this (not compiled):

public void savefunc(){
    List<String> myDate = new ArrayList<String>(); //To store the formatted dates
    SimpleDateFormat thedate = new SimpleDateFormat("dd/MM/yyyy"); 
    Date d=new Date(); //the current date
    String sd = thedate.format(d); // sd contains "16/04/2013", the formatted date
    myDate.add(sd);

    double thedata=Double.parseDouble(value.getText().toString().trim());
    mydata.add(thedata);
    ...
    BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(fos));
    for (int i=0;i<mydate.size();i++){
       bw.write(mydate.get(i)+","+mydata.get(i)+"\n");
    }
}


public void readfunc(){

    SimpleDateFormat thedate = new SimpleDateFormat("dd/MM/yyyy"); 
    Date d;
    BufferedReader br = new BufferedReader(new InputStreamReader(fis));

    do {
        s = br.readLine();     
        if (s != null ){
            String[] splitLine = s.split(","); //first substring is the formatted date
            date.add(thedate.parse(splitLine[0])); //do something with exception
            data.add(Double.parseDouble(splitLine[1]));
...

Hope it helps.

answered Apr 16 '13 at 22:21

eltabo

3,749
1
21
33

:First of all ,thanks for helping.Now, the line "date.add(thedate.parse(splitLine[0]));"doesn't work because "date" is a List.Anyway , I did "Date d=new Date(); String formattedDate=thedate.format(d); and date.add(formattedDate); instead of date.add(thedate.parse(splitLine[0])); " and it works!I save the file which has 2 columns. – George Apr 17 '13 at 07:32
:Now,the only problem is the gpraph.As far as I understand in order to have dates in x-axis I must have List.So, I am trying to convert the strings we created to dates.So, I create a List Ddate = new ArrayList(); and I am trying to populate it with the dates List(from before).I do :SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy"); Date convertedDate=new Date(); try{ for (int k=0;k – George Apr 17 '13 at 07:36
@George In order to have dates on the X axis, you either create a time chart or add custom labels on the X axis. – Dan D. Apr 17 '13 at 22:27
@Dan:Hello, I use "TimeSeries series = new TimeSeries("Showing data"); for (int i=0;i – George Apr 18 '13 at 07:14
Your code doesn't show anywhere the type of chart you are building. ChartFactory.getTimeChartIntent See this: https://code.google.com/p/achartengine/source/browse/trunk/achartengine/demo/org/achartengine/chartdemo/demo/chart/ProjectStatusChart.java – Dan D. Apr 18 '13 at 13:08
@Dan:I use TimeSeries and ChartFactory.getLineChartIntent. I tried 2 things.1) Store Dates in String List and then (in Linegraph) copy these values to Date List . 2) Store Dates (Date List) and retrieve also Dates (in Linegraph).Both, result in showing big nnumbers in x axis.. – George Apr 18 '13 at 13:15
@Dan:A last one please.If I want to plot a scatter graph and at the same time use the date x axis (hence,ChartFactory.getTimeChartView) ,what should I do?Because as a line graph when I enter same values the same date ,the graph overlaps.Or, can you point me to an example of adding custom labels on the X axis you said before?Thanks! – George Apr 18 '13 at 15:56
Please ask a separate question describing what you are trying to do. – Dan D. Apr 18 '13 at 16:58

score 0 · Answer 2 · edited May 23 '17 at 10:25

for dynamic plots use GraphicalView rather then intent::

 public GraphicalView mChartView;

creat a xml::

<RelativeLayout 
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   xmlns:android="http://schemas.android.com/apk/res/android">

<LinearLayout
    android:id="@+id/graph"
    android:layout_width="fill_parent"
    android:layout_height="145dip" >

  </LinearLayout>
</RelativeLayout>

then in ur code :

 LinearLayout layout = (LinearLayout) findViewById(R.id.graph);
 mChartView = ChartFactory.mChartView = ChartFactory.getLineChartView(getBaseContext(), dataset, renderer)
 layout.addView(mChartView);

After entering values you read from edit text fields right:
then you are passing the new values to add in respective arraylists
then you should call the code for linegraph again after adding new values and remember to clear series before reading arraylists (ie. dataset.clear();) ie. when line code function starts at beginning add dataset.clear(); because if u dont clear data will overlap and may through exception or line may look thick at old data ...

then call mChartView.repaint(); to refresh graph

these links too ll help u link1 link2

:Hello , If you can help me with my example please.I don't want to do sth else now.Also , the links aren't for this kind of problem.Thanks — George, Apr 15 '13 at 13:32
if u have already done for static data then mail it to me ll edit it to work for dynamic data — Kiran, Apr 15 '13 at 15:44

achartengine - can't figure how to use dates as x axis - the file I save is empty

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