Example usage for org.jfree.data.time RegularTimePeriod previous

Introduction

In this page you can find the example usage for org.jfree.data.time RegularTimePeriod previous.

Prototype

public abstract RegularTimePeriod previous();

Source Link

Document

Returns the time period preceding this one, or null if some lower limit has been reached.

Usage

From source file:com.dreikraft.axbo.timeseries.TimeSeriesUtil.java

/**
 * Create a moving average time series from a given source series.
 *
 * @param source the source timeseries//  w w w.jav  a2s. com
 * @param preLen number of timeperiods before current time period included in
 * moving average calculation
 * @param postLen number of timeperiods after current time period included in
 * moving average calculation
 * @return a moving average time series
 */
public static TimeSeries createMovingAverage(final TimeSeries source, final int preLen, final int postLen) {

    final int len = preLen + postLen + 1;
    final TimeSeries result = new TimeSeries(source.getKey());
    final RegularTimePeriod lastTimePeriod = source.getTimePeriod(source.getItemCount() - 1);

    // process all timeperiods including empty ones
    RegularTimePeriod t = source.getTimePeriod(0);
    while (!(t.getFirstMillisecond() > lastTimePeriod.getFirstMillisecond())) {

        // calculate the moving avg value for the current time period
        double value = getValue(source, t);
        RegularTimePeriod ti = t;
        for (int i = 0; i < preLen; i++) {
            ti = ti.previous();
            value += getValue(source, ti);
        }
        ti = t;
        for (int i = 0; i < postLen; i++) {
            ti = ti.next();
            value += getValue(source, ti);
        }

        // add the moving avg value to the included time periods
        result.addOrUpdate(t, value / len);
        t = t.next();
    }

    return result;
}

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From source file:org.jfree.chart.demo.TimeSeriesDemo11.java

/**
 * Creates a sample dataset./*from   w w w  .  j  a v  a2s .  c  o m*/
 * 
 * @param name  the dataset name.
 * @param base  the starting value.
 * @param start  the starting period.
 * @param count  the number of values to generate.
 *
 * @return The dataset.
 */
private XYDataset createDataset(final String name, final double base, final RegularTimePeriod start,
        final int count) {

    final TimeSeries series = new TimeSeries(name, start.getClass());
    RegularTimePeriod period = start;
    double value = base;
    for (int i = 0; i < count; i++) {
        series.add(period, value);
        period = period.previous();
        value = value * (1 + (Math.random() - 0.495) / 10.0);
    }

    final TimeSeriesCollection dataset = new TimeSeriesCollection();
    dataset.addSeries(series);

    return dataset;

}

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