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 Date Scale on x-axis |
| Posted by Alden on Jun-06-2012 15:32 |
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Hi Peter,
On a multiline chart, if I have three sets of data to plot each with different sets of date
points for their data(i.e. each data point has it's own date), how can I add a date range to
the x-axis and have the data point display at their relevant date point on the x-axis for all
three lines? Obviously I can't display three different sets of date labels on the x-axis.
If it helps, my data is passed into the charting class using a LinkedHashMap<String,
ArrayList<Object[]>>; where each Object[] in each arraylist has a date and a
double value. There can be multiple Arraylists in the hashmap.
Thanks,
Alden |
| Re: Date Scale on x-axis |
| Posted by Peter Kwan on Jun-07-2012 01:03 |
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Hi Alden,
There is a sample code "Uneven Data Points" included in ChartDirector, which should be close to your case.
In brief, the code is like:
//assuming the followings are your (x, y) data series
double[] yData0;
java.util.Date[] xDates0;
double[] yData1;
java.util.Date[] xDates1;
double[] yData2;
java.util.Date[] xDates2;
Layer layer0 = c.addLineLayer(yData0, .....);
layer0.setXData(xDates0);
Layer layer1 = c.addLineLayer(yData1, .....);
layer0.setXData(xDates1);
Layer layer2 = c.addLineLayer(yData2, .....);
layer0.setXData(xDates2);
//You can let ChartDirector auto-scale the x-axis, just like how it auto-scales the
//y-axis, or you may use Axis.setDateScale to set the x-axis scale.
c.xAxis().setDateScale(startDate, endDate, labelSpacingInSeconds);
//You can optionally use Axis.setLabelFormat to control the label format.
c.xAxis().setLabelFormat("{value|yyyy-mm-dd}");
Hope this can help.
Regards
Peter Kwan |
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