I have created a stacked bar chart in which I show a count on the y axis and dates on the x axis. The problem is that when I have many dates on the x axis it gets very cluttered and impossible to read. I would like to show only some of the dates, e.g one date per week. Is that possible? I am using ChartFactory.createStackedBarChart() to create the chart, and I have the data in a DefaultCategoryDataSet.
Any input is appreciated!
For a CategoryAxis, which is used the for the domain axis in a StackedBarChart, you have considerable flexility with the method setCategoryLabelPositions(). Typical usage is illustrated in the BarChartDemo1 source, shown here.
CategoryAxis domainAxis = plot.getDomainAxis();
domainAxis.setCategoryLabelPositions(
CategoryLabelPositions.createUpRotationLabelPositions(Math.PI / 6.0));
Have you tried overriding the generateLabel methods in the label generator? Something like:
chart.getCategoryPlot().getRenderer().setBaseItemLabelGenerator(
new CategoryItemLabelGenerator() {
public String generateColumnLabel(CategoryDataset dataset, Integer column) {
if(column % 7 == 0)
super.generateColumnLabel(dataset, column)
else
""
}
}
);
I haven't tested the code, but it should only output a label every 7 columns. More info on the label generator is here: http://www.jfree.org/jfreechart/api/javadoc/org/jfree/chart/labels/CategoryItemLabelGenerator.html
Related
I have two BarChartDataSets. One of them is always size 3 and the other is either 2 or 3. I tested out the code in version 3.0.0 and everything was working fine. When 3.0.1 came out, it broke my chart. I have the correct number of bars always, but I have six labels instead of 5 when the second dataset is only size 2. It has nothing to do with the stringForValue Delegate function. I set the X values using int's that are associated linearly with the Bar I want represented at that index, so each bar is equally spaced when working properly, but none of them are equally spaced when I have 6 labels and 5 bars.
The one on the left shows the issue and the one on the right shows what it looks like when my BarChartDataSet is size 3. It is duplicating whatever the last value on the chart is and adding it as a 6th label on the left. In 3.0.0 the one on the left would have only had 5 labels.
I dug into their code and where they create the labels in XAxisRendererHorizontalBarChart.swift right before they call drawLabel() I callprint("xAxis entries: \(xAxis.entries.count)")which prints xAxis entries: 6to the console even though right before I call let chartData = BarChartData(dataSets: [chartDataSet1, chartDataSet2])I callprint("dataEntries1 count: \(dataEntries1.count),
dataEntries2 count: (dataEntries2.count)")which prints dataEntries1 count: 3, dataEntries2 count: 2
First, xAxis.entries and dataSet.entries are totally different.
xAxis.entries are the values that being displayed on the axis as labels, while dataSet.entries is the value displayed for the data, e.g. the dot value in line chart, or the bar value for bar chart.
for x axis, it calculate the label count by your data entries min/max value. In Chart 3.0, x axis behaves like y axis, so it calculates x axis entries like y axis, please take a look at computeAxisValues() for details.
So xAxis.entries and dataSet.entries don't have to be equal size.
If you want to set the x axis label count same as your bars count, you can call: setLabelCount(5(6), true):
open func setLabelCount(_ count: Int, force: Bool)
{
self.labelCount = count
forceLabelsEnabled = force
}
Note, don't call the labelCount setter as it's different:
/// the number of label entries the axis should have
/// max = 25,
/// min = 2,
/// default = 6,
/// be aware that this number is not fixed and can only be approximated
open var labelCount: Int
{
get
{
return _labelCount
}
set
{
_labelCount = newValue
if _labelCount > 25
{
_labelCount = 25
}
if _labelCount < 2
{
_labelCount = 2
}
forceLabelsEnabled = false
}
}
I generate a transparent chart that lets the background of a web page be seen through it.
So far I've done this (omited the populating of dataset for brevity):
lineChartObject=ChartFactory.createLineChart("Title","Legend","Amount",line_chart_dataset,PlotOrientation.VERTICAL,true,true,false);
CategoryPlot p = lineChartObject.getCategoryPlot();
Color trans = new Color(0xFF, 0xFF, 0xFF, 0);
lineChartObject.setBackgroundPaint(trans);
p.setBackgroundPaint(trans);
for (int i=0;i<=3;i++){
lineChartObject.getCategoryPlot().getRenderer().setSeriesStroke(i, new BasicStroke(3.0f));
lineChartObject.getCategoryPlot().getRenderer().setBaseItemLabelsVisible(false);
}
Which renders this:
I cannot find a way of:
Removing border of plot (1)
Removing border of leyend as well as making it transparent (3)
Making the labels on the X axis (2) to behave intelligently as the labels of Y axis do (A). Labels of Y axis space themselves so as to not clutter the graph, for example if I rendered the graph smaller, it would show fewer labels, like this:
Edit: X label domain is dates.
For (1) try:
plot.setOutlineVisible(false);
For (2), a common reason for having too many categories along the x-axis is that the data is actually numerical, in which case you should be using XYPlot rather than CategoryPlot. With XYPlot, the x-axis scale adjusts in the same way that the y-axis does.
Edit from OP: Using a TimeSeriesChart with a TimeSeriesCollection as XYDataSet did the work! (fotgot to say X domain is dates)
For (3) try:
LegendTitle legend = chart.getLegend();
legend.setFrame(BlockBorder.NONE);
legend.setBackgroundPaint(new Color(0, 0, 0, 0));
I am using GWT Highcharts to draw a bar-graph.
The values for both X and Y axis are coming from the MySQL database.
The chart will display a graph having vc values on Y-Axis and corresponding sampleno (i.e. Date) on X-Axis.
Following is the code of loop that fills the series.
for(int i = 0; i < stats.size(); i++)
{
long sample = Long.parseLong(stats.get(i).getSampleno() + "");
long n = (sample*60000);
pointDate = new Date(n);
Point point = new Point( /* pointDate?? */ ,stats.get(i).getVc());
serPt.addPoint(point);
}
The sampleno is some timestamp which I am converting into Date.
Now, Could you guide me how can I display this date as values on x-axis.
An example on Moxie Group site does this, but the dates are in a fixed range there.
Please comment if any further explanation is needed.
I advice to use labels formatter http://api.highcharts.com/highcharts#xAxis.labels.formatter and then return value by using http://api.highcharts.com/highcharts#Highcharts.dateFormat()
labels: {
formatter: function() {
return Highcharts.dateFormat('%Y/%m/%d',this.value);
}
}
I'm trying to add a second Y axis to a StockChart with the Moxieapps Highcharts wrapper, but without success. I need to add a new axis on the right side of the chart, and would expect the following code to work:
StockChart chart = new StockChart();
YAxis firstYAxis = chart.getYAxis(0);
firstYAxis.setAxisTitleText("First Y axis");
Series firstSeries = chart.createSeries();
firstSeries.setPoints(/* Imagine lots of points. */);
firstSeries.setYAxis(0); // Not required since 0 is the default Y axis.
chart.addSeries(firstSeries);
YAxis secondYAxis = chart.getYAxis(1);
secondAxis.setOpposite(true); // *Should* put the axis on the right side.
secondYAxis.setAxisTitleText("Second Y axis");
Series secondSeries = chart.createSeries();
secondSeries.setPoints(/* Imagine lots of points. */);
secondSeries.setYAxis(1); // *Should* add the series to the second Y axis.
chart.addSeries(secondSeries);
// Somehow the second series ends up being in the navigator...
chart.setOption("navigator/enabled", true);
chart.setOption("scrollbar/enabled", true);
add(chart);
The second Y axis does not even render. If I don't add the second series to the second Y axis, it shows up (as expected) as values on the first Y axis.
Has anyone successfully added multiple Y axes on a StockChart, that can tell me what I'm doing wrong here? Thanks a lot in advance!
I had the same problem and it seems that GWT-HighCharts is the problem. You must create YAxises manually via native calls. Here is the solution;
HighCharts Stock Chart error code 18
Specifically I am looking to add text annotations to specific locations to a JFreeChart that is being output to a png file for web use. Can/how do annotations get added to pie charts. I have been able to successfully add annotations to XYPlots, but don't know how to overlay or add one to a PiePlot.
My full task is to use the PiePlot to create a sort of clock. So far everything has worked great, but now I need to add labels at the 12, 3, 6, and 9 o'clock locations and completely stumped.
Adam
Bit of an old question, but here's how I did something similar (annotation at 1, 2, 3, ... o'clock positions) using a polar plot. It uses a ChoiceFormatter and the NumberTickUnit:
final JFreeChart chart = ChartFactory.createPolarChart(
"HAPI Hourly Usage (UTC)", ds, true, true, false);
final PolarPlot plot = (PolarPlot) chart.getPlot();
// Create a ChoiceFormat to map the degrees to clock positions
double[] limits = new double[12];
String[] formats = new String[12];
limits[0] = 0;
formats[0] = "12";
// degrees = 360/12
for (int i = 1; i < limits.length; i++) {
limits[i] = degrees * (i);
formats[i] = Integer.toString(i);
}
ChoiceFormat clock = new ChoiceFormat(limits, formats);
TickUnit tickUnit = new NumberTickUnit(degrees, clock);
// now configure the plot
plot.setAngleTickUnit(tickUnit); // sets the ticks
plot.setAngleLabelsVisible(true); // makes the labels visible
plot.setAngleLabelPaint(Color.LIGHT_GRAY); // user choice
plot.setAngleGridlinesVisible(true); // must set this to display the
// labels
plot.setAngleGridlinePaint(Color.BLACK); // plot's background color
// (makes lines invisible)
plot.setRadiusGridlinesVisible(false); //turn off the radius value circles
ValueAxis axis = plot.getAxis();
axis.setTickLabelsVisible(false); //turn off the radius value labels
winds up looking like http://img522.imageshack.us/img522/6693/hapihours.jpg
After a fairly strenuous search I don't believe this is currently possible (JFreeChart 1.0.13).
Possible options are:
Create a second chart with an XYPlot to generate a second image with needed annotations. Overlay this image on the page. This option is bad because it doubles the number of chart images to be uploaded.
Set the image as a background on the page and HTML the text over the image. Bad because it isn't maintainable and makes a headache of data transfer.
Personally I am just going to find another way to communicate the information in the title, but I wanted to post my findings for the next person.
Adam