Package org.rrd4j.data

Class Variable

java.lang.Object
org.rrd4j.data.Variable
Direct Known Subclasses:
Variable.AVERAGE, Variable.FIRST, Variable.LAST, Variable.LSLCORREL, Variable.LSLINT, Variable.LSLSLOPE, Variable.MAX, Variable.MIN, Variable.PERCENTILE, Variable.STDDEV, Variable.TOTAL
public abstract class Variable
extends Object
An abstract class to help extract single value from a set of value (VDEF in rrdtool) It can be used to add new fancy statistical calculation with rrd values

  • Nested Class Summary

    Nested Classes 
    Modifier and Type Class Description
    static class  Variable.AVERAGE
    Calculate the average of the data points.
    (package private) static class  Variable.ComparPercentElemen
    The sort used by rrdtool for percent, where NaN < -INF < finite values < INF
    static class  Variable.FIRST
    Find the first valid data point and it's timestamp
    static class  Variable.LAST
    Find the first last valid point and it's timestamp
    static class  Variable.LSLCORREL
    Calculate the correlation coefficient of the least squares line.
    static class  Variable.LSLINT
    Calculate the y-intercept of the least squares line.
    static class  Variable.LSLSLOPE
    Calculate the slop of the least squares line.
    static class  Variable.MAX
    The biggest of the data points and it's time stamp (the first one) is stored.
    static class  Variable.MIN
    The smallest of the data points and it's time stamp (the first one) is stored.
    (package private) static class  Variable.PercentElem
    Store all the informations about a datasource point, for predictive and consistent sorting
    static class  Variable.PERCENTILE
    Find the point at the n-th percentile.
    static class  Variable.PERCENTILENAN  
    static class  Variable.STDDEV
    Calculate the standard deviation for the data point.
    static class  Variable.TOTAL
    Calculate the sum of the data points.
    static class  Variable.Value
    This class store both the value and the time stamp It will be used by graph rendering legend

  • Field Summary

    Fields 
    Modifier and Type Field Description
    static Variable.Value INVALIDVALUE  

  • Constructor Summary

    Constructors 
    Constructor Description
    Variable()  

  • Method Summary

    Modifier and Type Method Description
    (package private) void calculate​(Source s, long start, long end)
    Used to calculate the needed value from a source, this method call the abstract method fill(long[], double[], long, long).
    protected abstract Variable.Value fill​(long[] timestamps, double[] values, long start, long end)
    This method is call with the needed values, extracted from the datasource to do the calculation.
    Variable.Value getValue()  

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

  • Constructor Details

  • Method Details

    • calculate

      void calculate​(Source s, long start, long end)
      Used to calculate the needed value from a source, this method call the abstract method fill(long[], double[], long, long).
      Parameters:
      s -
      start -
      end -

    • getValue

      public Variable.Value getValue()

    • fill

      protected abstract Variable.Value fill​(long[] timestamps, double[] values, long start, long end)
      This method is call with the needed values, extracted from the datasource to do the calculation. Value is to be filled with both the double value and a possible timestamp, when it's used to find a specific point
      Parameters:
      timestamps - the timestamps for the value
      values - the actual values
      start - the start of the period
      end - the end of the period
      Returns:
      a filled Value object