Develop Reference

MPAndroidChart - wrong values in getFormattedValue method. Where they come from?

I am working with a project which is using MPAndroidChart library which makes me really crazy, I want to remove it.
The problem is I have created a custom ValueFormatter and I can't understand where these values come from, all are wrong.
private void setData() {
for (int i = 1; i <= 10; i++) {
Entry entry = new Entry(i, i);
values.add(entry);
}
IAxisValueFormatter valueFormatter = new myValueFormatter();
XAxis xAxis = mChart.getXAxis();
xAxis.setValueFormatter(valueFormatter);
LineDataSet set1 = new LineDataSet(values, "DataSet 1");
ArrayList<ILineDataSet> dataSets = new ArrayList<ILineDataSet>();
dataSets.add(set1); // add the datasets
// create a data object with the datasets
LineData data = new LineData(dataSets);
// set data
mChart.setData(data);
}
custom formatter class:
I have an array which has 1,2,3,4,5,6,7,8,9,10 values
but I get 2,4,6,8,10 values in getFormattedValue method.
public classmyValueFormatter implements IAxisValueFormatter {
#Override
public String getFormattedValue(float value, AxisBase axis) {
System.out.println(value); //Here I get odd values where they come from I don't know.
}
}

Well, generally that's how library is written. Have a look here:
https://github.com/PhilJay/MPAndroidChart/blob/master/MPChartLib/src/main/java/com/github/mikephil/charting/renderer/XAxisRenderer.java#L205
String label = mXAxis.getValueFormatter().getFormattedValue(mXAxis.mEntries[i / 2], mXAxis);
Author's intention was probably to give more spacing between labels. If you think this is a bug, submit issue to library's repository on Github.

How to Draw Financial Transactions Graph using MPAndroid Chart Library

I'm Trying to create a Financial transactions Graph like banks ,As shown in this Pic
When Customer Selects the Start and End Date , Graph should show the Months on XAxis and Date and Amount when transaction was done as shown by White filled circle .
I have tried examples provided by library but I wasn't able to use string labels and plot real time values !

Try using IAxisValueFormatter
final String[] months = new String[] { "Jan", "Feb", "Mar", "Apr" };
IAxisValueFormatter formatter = new IAxisValueFormatter() {
#Override
public String getFormattedValue(float value, AxisBase axis) {
return months [(int) value];
}
#Override
public int getDecimalDigits() { return 0; }
};
XAxis xAxis = mLineChart.getXAxis();
xAxis.setGranularity(1f);
xAxis.setValueFormatter(formatter);

Drawing horizontal bar chart with `MPAndroidChart`

Does anybody have an idea on how to make this: my app image look like this: how it should be?
My question is: how to make each line of the Horizontal Bar Chart fill between the two lines?
for (Iterator<Map.Entry<String, Float>> iterator = structuredData.entrySet().iterator(); iterator.hasNext();) {
Map.Entry<String, Float> entry = iterator.next();
//i*10 => starting position of the bar
horizontalBarChartArr.add(new BarEntry((i*10), entry.getValue()));
names.add(entry.getKey());
i++;
}
XAxis xAxis = horizontalBarChart.getXAxis();
xAxis.setValueFormatter(new IAxisValueFormatter() {
#Override
public String getFormattedValue(float value, AxisBase axis) {
return names.get((int)value % names.size());
}
});
xAxis.setDrawGridLines(true);
xAxis.setDrawAxisLine(true);
BarDataSet barDataSet = new BarDataSet(horizontalBarChartArr, "Day Expenses");
barDataSet.setColors(Color.RED);
BarData data = new BarData(barDataSet);
data.setBarWidth(9f);
horizontalBarChart.setDoubleTapToZoomEnabled(false);
Description a = new Description();
a.setText("");
horizontalBarChart.setDescription(a);
horizontalBarChart.invalidate();
horizontalBarChart.animateY(1200);
horizontalBarChart.setData(data);

Check this example to your case:
https://github.com/ddanny/achartengine
It´s Automatically exported from code.google.com/p/achartengine

How to add x axis as datetime label in MPAndroidChart?

I implemented line chart (MPAndroidChart library) for temperature report in my project.In X axis datetime should be plotted and Y axis temperature should be plotted.
I just added datetime as string in X axis label but it's collapsed. So please anyone guide me.

Using version 3.0+ of the MPAndroidChart:
Set formatter to the x axis (created below):
// Formatter to adjust epoch time to readable date
lineChart.xAxis.setValueFormatter(new LineChartXAxisValueFormatter());
Create a new class LineChartXAxisValueFormatter:
public class LineChartXAxisValueFormatter extends IndexAxisValueFormatter {
#Override
public String getFormattedValue(float value) {
// Convert float value to date string
// Convert from seconds back to milliseconds to format time to show to the user
long emissionsMilliSince1970Time = ((long) value) * 1000;
// Show time in local version
Date timeMilliseconds = new Date(emissionsMilliSince1970Time);
DateFormat dateTimeFormat = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.getDefault());
return dateTimeFormat.format(timeMilliseconds);
}
}
When the entries are added to the chartDataArray they are added in seconds, not milliseconds, to avoid potential precision issues with inputting as a float (i.e. milliseconds divided by 1000).
chartDataArray.add(new Entry(secondsSince1970Float, yValueFloat));
Happy coding!

Try the following.
To set the X Axis
XAxis xAxis = mChart.getXAxis();
xAxis.setPosition(XAxis.XAxisPosition.BOTTOM);
xAxis.setValueFormatter(new MyXAxisValueFormatter());
xAxis.setLabelsToSkip(0);
Create a new class MyXAxisValueFormatter implement XAxisValueFormatter
public class MyXAxisValueFormatter implements XAxisValueFormatter {
#Override
public String getXValue(String dateInMillisecons, int index, ViewPortHandler viewPortHandler) {
try {
SimpleDateFormat sdf = new SimpleDateFormat("dd MMM");
return sdf.format(new Date(Long.parseLong(dateInMillisecons)));
} catch (Exception e) {
return dateInMillisecons;
}
}
Hope this helps

Further from #Ben's answer, if you are creating BarChart, and the time span of the bar is like an hour or a day, and you are supplying with millisecond or second data, you will end up getting the bars too thin to be visible. This is a bug posted in 2017 (https://github.com/PhilJay/MPAndroidChart/issues/2892) and remains unresolved to date unfortunately.
A workaround was proposed and it is to convert the millisecond values into your time span of the bar before setting then into BarEntry. My time span is a day, so
I have the formatter as:
static class BarChartXAxisValueFormatter extends IndexAxisValueFormatter {
#Override
public String getFormattedValue(float value) {
// Convert float value to date string
// Convert from days back to milliseconds to format time to show to the user
long emissionsMilliSince1970Time = TimeUnit.DAYS.toMillis((long)value);
// Show time in local version
Date timeMilliseconds = new Date(emissionsMilliSince1970Time);
SimpleDateFormat dateTimeFormat = new SimpleDateFormat("MM-dd");
return dateTimeFormat.format(timeMilliseconds);
}
}
And I set the X axis with:
xAxis.setValueFormatter(new BarChartXAxisValueFormatter());
Then when setting the data to the bar, I have
new BarEntry(TimeUnit.MILLISECONDS.toDays((long)valX), valY).

If it still actually...
class DateAxisValueFormatter implements IAxisValueFormatter {
private String[] mValues;
SimpleDateFormat sdf = new SimpleDateFormat("yyyy.MM.dd.hh");
public DateAxisValueFormatter(String[] values) {
this.mValues = values; }
#Override
public String getFormattedValue(float value, AxisBase axis) {
// "value" represents the position of the label on the axis (x or y)
return mValues[(int) value];
}
}
And your must on Create put String[] values (public DateAxisValueFormatter(String[] values) ) where each value is a DateString.
Data series Entries for X (new Entry(forX,forY)) must be a flat array = 0,1,2,3,4
Sorry, my poor English, I am from Russia. From 1988 main chief of RealTime Control System Developer Company for Hydro Power Plants (www.asu-epro.ru).
Borodatov Michael miclosoft#mail.ru

Android - MPAndroidChart LineChart, not able to plot according to value date

I am using MPAndroidChart for my line chart.
I have date values and score values.
Example: on 11/10/2016 my score was 45.
I am struggling with the dates. Not sure how to set it in my setYAxisValues.
I am getting my values from a rest api and putting it in the graph.
This part is where i have my problem.
yVals.add(new Entry(Float.valueOf(ocd.getScore()), foo));
If I change foo to a normal int value like 1, 2, 3 I have no problem. The graph is working. The issue, i need to use dates to plot my value at the correct place.
#Override
protected void onPostExecute(List<ResultModel> result) {
super.onPostExecute(result);
//populating my yAxis with values from rest
for (ResultModel ocd : resModelList){
long unixSeconds = Long.parseLong(ocd.getPost_date());
Date date = new Date(unixSeconds*1000L);
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy");
String formattedDate = sdf.format(date);
int foo = Integer.parseInt(formattedDate);
yVals.add(new Entry(Float.valueOf(ocd.getScore()), foo));
}
}
The X axis is working
//set vales
private ArrayList<String> setXAxisValues(){
xVals = new ArrayList<String>();
//MM/dd/yyyy
xVals.add("01/01/2016");
xVals.add("02/01/2016");
xVals.add("03/01/2016");
xVals.add("04/01/2016");
xVals.add("05/01/2016");
return xVals;
}
private ArrayList<Entry> setYAxisValues(){
yVals = new ArrayList<Entry>();
return yVals;
}
Thanks in advance

I had the similar issue, the point is - MPChart library cannot have anything but float for X axis. I'd suggest you to have X axis represented by date's millis. Suppose you have four values with dates "01/01/2016", "02/01/2016", "03/01/2016", "04/01/2016", "05/01/2016". You add values like
yVals.add(new Entry(Float.valueOf(ocd.getScore()), "01/01/2016".toMillis()));
"01/01/2016".toMillis() is pseudocode of course, you need to convert your date to int (float).
Then, set up minX as "01/01/2016".toMillis(), maxX as"04/01/2016".toMillis(),
and provide a label formater which will format this millis back to string dates:
private class LabelFormatter implements AxisValueFormatter {
private Context context;
private LabelFormatter(Context context) {
this.context = context;
}
#Override
public int getDecimalDigits() {
return -1;
}
#Override
public String getFormattedValue(float value, AxisBase axis) {
return DateUtils.formatDateTime(context, (long) value, DateUtils.FORMAT_SHOW_DATE);
}
}