Not able to display graph using achartengine. - achartengine

Question

I am retrieving data from my database and storing in 2 arrays. 1 array consists of temperature values and the other has date . I am using TimeChart of achartengine but still am not able to display the graph. It works well when I use random values for x axis and use LineChart. The x axis labels are 1970-01-01 5:30:00 . It seems that my database values are not being taken for the graph. can somebody plz help?
package com.ti.sensortag;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import org.achartengine.ChartFactory;
import org.achartengine.GraphicalView;
import org.achartengine.chart.PointStyle;
import org.achartengine.model.TimeSeries;
import org.achartengine.model.XYMultipleSeriesDataset;
import org.achartengine.renderer.XYMultipleSeriesRenderer;
import org.achartengine.renderer.XYSeriesRenderer;
import DB.DBHandler;
import DB.Temperature;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.Color;
import android.graphics.Paint.Align;
import android.util.Log;
import android.view.Menu;
import android.widget.LinearLayout;
public class Temperature_Graph extends Activity {
DBHandler db;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_temperature__graph);
GraphicalView mChart;
db=new DBHandler(getApplicationContext());
//reading data from database
List<Temperature> temp=db.getAllTempReadings();
int arraySize=temp.size();
double TArray[]=new double[arraySize]; //array to hold temperature values
String TSArray[]=new String[arraySize]; // array to hold timestamp values
Date dateArray[]=new Date[TSArray.length]; // array to hold timestamp (String) converted to (date)
for(int i=0;i<arraySize;i++){
TArray[i]=Double.parseDouble(temp.get(i).getTemperature());
TSArray[i]=temp.get(i).getTimestamp();
//converting string to date
SimpleDateFormat sdf=new SimpleDateFormat("dd-MM-yyyy hh:mm:ss");
try {
Date result=sdf.parse(TSArray[i]);
dateArray[i]= result;
Log.d("dateArray",String.valueOf(dateArray[i]));
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//TimeSeries
TimeSeries tSeries=new TimeSeries("Temperature");
TimeSeries hSeries=new TimeSeries("35"); // hypothermia
TimeSeries fSeries=new TimeSeries("37.5"); // fever
TimeSeries nSeries=new TimeSeries("Normal-36.4");
double hArray[]=new double[arraySize];
double fArray[]=new double[arraySize];
double nArray[]=new double[arraySize];
double numbers[]=new double[arraySize];
for(int i=0;i<TSArray.length;i++){
hArray[i]=35;
fArray[i]=37.5;
nArray[i]=36.4;
//adding values to the timeseries
tSeries.add(dateArray[i], TArray[i]);
hSeries.add(dateArray[i], hArray[i]);
nSeries.add(dateArray[i], nArray[i]);
fSeries.add(dateArray[i], fArray[i]);
}
//Dataset
XYMultipleSeriesDataset dataset=new XYMultipleSeriesDataset();
//adding series to the dataset
dataset.addSeries(tSeries);
dataset.addSeries(hSeries);
dataset.addSeries(nSeries);
dataset.addSeries(fSeries);
//properties of temperature series
XYSeriesRenderer tRenderer=new XYSeriesRenderer();
tRenderer.setColor(Color.YELLOW);
tRenderer.setPointStyle(PointStyle.DIAMOND);
tRenderer.setFillPoints(true);
final NumberFormat tempValueFormat=new DecimalFormat("##.##");
tRenderer.setChartValuesFormat(tempValueFormat);
tRenderer.setChartValuesTextSize(20);
tRenderer.setDisplayChartValues(true);
tRenderer.setChartValuesSpacing((float)0.5);
tRenderer.setChartValuesTextSize(20);
//properties of hSeries
XYSeriesRenderer hRenderer=new XYSeriesRenderer();
hRenderer.setColor(Color.MAGENTA);
hRenderer.setLineWidth(3);
//properties of fSeries
XYSeriesRenderer fRenderer=new XYSeriesRenderer();
fRenderer.setColor(Color.RED);
fRenderer.setLineWidth(3);
//properties of nSeries
XYSeriesRenderer nRenderer=new XYSeriesRenderer();
nRenderer.setColor(Color.CYAN);
nRenderer.setLineWidth(3);
fRenderer.setLineWidth(3);
//properties of the chart
XYMultipleSeriesRenderer mRenderer=new XYMultipleSeriesRenderer();
mRenderer.setBackgroundColor(Color.BLACK);
mRenderer.setPointSize(5);
mRenderer.setLabelsColor(Color.GREEN);
mRenderer.setChartTitle("TEMPERATURE LINE GRAPH");
mRenderer.setChartTitleTextSize(30);
mRenderer.setAxesColor(Color.WHITE);
mRenderer.setApplyBackgroundColor(true);
mRenderer.setAxisTitleTextSize(15);
mRenderer.setXTitle("TIME");
mRenderer.setYTitle("TEMPERATURE");
// mRenderer.setZoomButtonsVisible(true);
mRenderer.setXLabelsAngle(10);
mRenderer.setYLabelsAlign(Align.LEFT);
mRenderer.setYLabels(15);
mRenderer.setXLabels(10);
mRenderer.setXLabelsAlign(Align.RIGHT);
mRenderer.setYLabelsAngle(10);
mRenderer.setXAxisMin(0);
mRenderer.setXAxisMax(30);
mRenderer.setShowGridX(true);
mRenderer.setShowGridY(true);
mRenderer.setXLabelsAlign(Align.CENTER);
mRenderer.setLabelsTextSize(20);
//mRenderer.setLegendTextSize(20);
// mRenderer.setLegendHeight(50);
//Adding series to renderer
mRenderer.addSeriesRenderer(tRenderer);
mRenderer.addSeriesRenderer(hRenderer);
mRenderer.addSeriesRenderer(nRenderer);
mRenderer.addSeriesRenderer(fRenderer);
LinearLayout layout=(LinearLayout)findViewById(R.id.graph);
mChart=(GraphicalView)ChartFactory.getTimeChartView(getBaseContext(), dataset, mRenderer, "yyyy-MM-dd hh:mm:ss");
layout.addView(mChart);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.temperature__graph, menu);
return true;
}
}

Answer 1

TimeChart does not seem to support displaying a minimum number of points at a time. when i removed
mRenderer.setXAxisMin(0);
mRenderer.setXAxisMax(30);
the graph got displayed. Is there any way to display a certain number of points at a time using TimeChart?