I am plotting the wind direction as a xyseries in a TimeChartView using aChartEngine along with windspeed (windspeed is a timeseries using left y-axis, winddir is XYSeries using right y-axis).
The problem I am facing is that as the windirection passes north, my values shift between 0 and 360, creating an ugly vertical line in my graph. I would prefer that if the values increased above 360 the graph just got clipped and resumed at 0. By filtering the values and inserting MathHelper.NULL_VALUE in my XYSeries (see code) I managed to get the graph as I wanted
double windDirTemp=0;
...
if (Math.abs(windDirValues[k] - windDirTemp)>300 ){
windDirTemp = windDirValues[k];
windDirSeries.add(convertedDateinDouble[k], MathHelper.NULL_VALUE );
}
else{
windDirSeries.add(convertedDateinDouble[k], windDirValues[k]);
}
The problem now is that my OnClickListener doesn't work anymore. The app crashes on
SeriesSelection seriesSelection = mChart.getCurrentSeriesAndPoint();
I assume that inserting the null-values to my series makes getCurrentSeriesAndPoint unable to get the SeriesIndex and can have something to do with the graph no longer being connected.
I would greatly appreciate any help to solve this. Could I filter the values differently? Is there an alternative to getCurrentSeriesAndPoint() I could try?
Thanks, Christian
EDIT:
I am using achartengine-1.1.0-rc2
My OneClickListener:
/**
* Setting a click event listener for the graph
*/
mChart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Format formatter = new SimpleDateFormat("HH:mm");
SeriesSelection seriesSelection = mChart.getCurrentSeriesAndPoint();
if (seriesSelection != null) {
int seriesIndex = seriesSelection.getSeriesIndex();
String selectedSeries = "Vindhastighet";
String unit = " m/s";
if (seriesIndex == 0)
selectedSeries = "Vindhastigheten";
else if (seriesIndex == 1)
selectedSeries = "Vindkast";
else {
selectedSeries = "Vindretningen";
unit = "\u00B0";
}
// Getting the clicked Date ( x value )
long clickedDateSeconds = (long) seriesSelection
.getXValue();
Date clickedDate = new Date(clickedDateSeconds);
String strDate = formatter.format(clickedDate);
// Getting the y value
int amount = (int) seriesSelection.getValue();
// Displaying Toast Message
Toast.makeText(
getBaseContext(),
selectedSeries + " kl " + strDate + " var "
+ amount + unit, Toast.LENGTH_LONG)
.show();
}
}
});
My logcat:
04-02 16:05:18.575: E/AndroidRuntime(29182): FATAL EXCEPTION: main 04-02 16:05:18.575: E/AndroidRuntime(29182): java.lang.NullPointerException 04-02 16:05:18.575: E/AndroidRuntime(29182): at org.achartengine.chart.XYChart.getSeriesAndPointForScreenCoordinate(XYChart.java:845) 04-02 16:05:18.575: E/AndroidRuntime(29182): at org.achartengine.GraphicalView.getCurrentSeriesAndPoint(GraphicalView.java:137) 04-02 16:05:18.575: E/AndroidRuntime(29182): at com.example.hellogooglemaps.WindChartActivity$1.onClick(WindChartActivity.java:116) 04-02 16:05:18.575: E/AndroidRuntime(29182): at android.view.View.performClick(View.java:4211) 04-02 16:05:18.575: E/AndroidRuntime(29182): at android.view.View$PerformClick.run(View.java:17267) 04-02 16:05:18.575: E/AndroidRuntime(29182): at android.os.Handler.handleCallback(Handler.java:615) 04-02 16:05:18.575: E/AndroidRuntime(29182): at android.os.Handler.dispatchMessage(Handler.java:92) 04-02 16:05:18.575: E/AndroidRuntime(29182): at android.os.Looper.loop(Looper.java:137) 04-02 16:05:18.575: E/AndroidRuntime(29182): at android.app.ActivityThread.main(ActivityThread.java:4898) 04-02 16:05:18.575: E/AndroidRuntime(29182): at java.lang.reflect.Method.invokeNative(Native Method) 04-02 16:05:18.575: E/AndroidRuntime(29182): at java.lang.reflect.Method.invoke(Method.java:511) 04-02 16:05:18.575: E/AndroidRuntime(29182): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006) 04-02 16:05:18.575: E/AndroidRuntime(29182): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773) 04-02 16:05:18.575: E/AndroidRuntime(29182): at dalvik.system.NativeStart.main(Native Method)
This was a bug in AChartEngine and is now fixed. You can download a version including this fix here.
来源:https://stackoverflow.com/questions/15764800/android-achartengine-getcurrentseriesandpoint-not-working-for-disconnected-g