OSID - osid.metering.Statistic Service Interface Definition

Interface	osid.metering.Statistic
Implements	`osid.OsidCompendium`
Used By	`osid.metering.StatisticList`
Used By	`osid.metering.StatisticLookupSession`
Description	A `Statistic` represents a reading of a `Meter` for a reference metered object over a period of time.
Method	getMeterId
Description	Gets the `Id` of the `Meter` associated with this reading.
Return	`osid.id.Id`		the `Id` of the `Meter`
Compliance	`mandatory`		This method must be implemented.
Method	getMeter
Description	Gets the `Meter` associated with this reading.
Return	`osid.metering.Meter`		the `Meter`
Errors	OPERATION_FAILED		unable to complete request
Compliance	`mandatory`		This method must be implemented.
Method	getMeteredObjectId
Description	Gets the metered object associated with this reading.
Return	`osid.id.Id`		the metered object `Id`
Compliance	`mandatory`		This method must be implemented.
Method	getSum
Description	Gets the total.
Return	`decimal`		the sum
Compliance	`mandatory`		This method must be implemented.
Method	getMean
Description	Gets the mean.
Return	`decimal`		the mean
Compliance	`mandatory`		This method must be implemented.
Method	getMedian
Description	Gets the median.
Return	`decimal`		the mean
Compliance	`mandatory`		This method must be implemented.
Method	getMode
Description	Gets the mode.
Return	`decimal`		the mode
Compliance	`mandatory`		This method must be implemented.
Method	getStandardDeviation
Description	Gets the standard deviation.
Return	`decimal`		the standard deviation
Compliance	`mandatory`		This method must be implemented.
Method	getRMS
Description	Gets the root mean square.
Return	`decimal`		the rms
Compliance	`mandatory`		This method must be implemented.
Method	getDelta
Description	Gets the difference between the end and start values.
Return	`decimal`		the delta
Compliance	`mandatory`		This method must be implemented.
Method	getPercentChange
Description	Gets the percent change between the end and start values (e.g. 50.25%).
Return	`decimal`		the delta
Compliance	`mandatory`		This method must be implemented.
Method	getAverageRate
Description	Gets the average rate of change.
Parameters	`osid.calendaring.DateTimeResolution`	`units`	the time units
Return	`decimal`		the average rate
Errors	NULL_ARGUMENT		`units` is `null`
Compliance	`mandatory`		This method must be implemented.
Method	getStatisticRecord
Description	Gets the statistic record corresponding to the given `Statistic` record `Type`. This method is used to retrieve an object implementing the requested record. The `statisticRecordType` may be the `Type` returned in `getRecordTypes()` or any of its parents in a `Type` hierarchy where `hasRecordType(statisticRecordType)` is `true`.
Parameters	`osid.type.Type`	`statisticRecordType`	the statistic record type
Return	`osid.metering.records.StatisticRecord`		the statistic record
Errors	NULL_ARGUMENT		`statisticRecordType` is `null`
	OPERATION_FAILED		unable to complete request
	UNSUPPORTED		`hasRecordType(statisticRecordType)` is `false`
Compliance	`mandatory`		This method must be implemented.