org.apache.spark.api.java.function.DoubleFunction Java Examples

The following examples show how to use org.apache.spark.api.java.function.DoubleFunction. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example #1
Source File: ChronixRDD.java    From chronix.spark with Apache License 2.0 5 votes vote down vote up 
/**
 * Action: Calculates the slope of a linear regression of every time series.
 *
 * Where: value = slope * timestamp
 * .. or:     y = slope * x
 *
 * @return the slopes (simple linear regression) of each an every time series in the RDD
 */
public JavaDoubleRDD getSlopes() {
    return this.mapToDouble((DoubleFunction<MetricTimeSeries>) mts -> {
                SimpleRegression regression = new SimpleRegression();
        mts.points().forEach(p -> regression.addData(p.getTimestamp(), p.getValue()));
                return regression.getSlope();
            }
    );
}
Example #2
Source File: ChronixRDD.java    From chronix.spark with Apache License 2.0 4 votes vote down vote up 
/**
 * Action: Counts the number of observations.
 *
 * @return the number of overall observations in all time series
 */
public long countObservations() {
    JavaDoubleRDD sizesRdd = this.mapToDouble(
            (DoubleFunction<MetricTimeSeries>) value -> (double) value.size());
    return sizesRdd.sum().longValue();
}