Sets the x values of the data points in the data sets.
In most ChartDirector XY chart layers, when a data set is added, only the y Values for the data points are needed. For example, in a bar layer, you just need to specify the values of the bars (y values). ChartDirector will automatically layout the bars evenly on the x-axis. You can then specify the labels on the x-axis using Axis.setLabels
In ChartDirector, this type of x-axis scaling is called "enumerated" scale. Please refer to Axis.setLabels
for a more detail explanation of "enumerated" scale.
However, in some cases, it may be necessary to specify the x values explicitly. For example, if a chart contains data points that are not evenly distributed on the x-axis, it is necessary to specify the x values explicitly. It is because enumerated scale always assume the data points are distributed evenly on the x- axis. In this case, the setXData method can be used to specify the x values for the data points.
In general, if the data points are evenly distributed on the x-axis, it is recommended enumerated x-scale be used and no x values are necessary. Even the data points are evenly distributed, except that some data points are missing, it is still possible to use enumerated x-scale by using the NoValue
constant to represent missing data points.
On the other hand, if the data points are by its nature not evenly distributed, the x values should be provided explicitly using the setXData method.
Each layer only supports one x values series. All data sets in the layer will use the same x value series. If two data sets have different x values, they should be put in two separate layers.
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