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TSTool Documentation Examples of Use <br />6.3 Time Series Ensemble Examples <br />The general term time series ensemble refers to groups of a time series, often shown in overlapping <br />fashion. Common ways to create ensembles are: <br />• Split time series into N -year lengths and shift to overlap. <br />• Run a model multiple times with different input, in order to generate many possible outcomes. <br />• Generate synthetic data to use as input to a model. <br />Several TSTool commands have been implemented to create and process time series traces. Many other <br />commands allow ensembles to be specified to provide a list of time series for processing. TSTool <br />manages ensemble data by using an ensemble identifier and optionally using a trace (sequence) number <br />for each time series, which when processing historical data is typically the starting historical year for the <br />trace. For most functionality, the ensemble is simply a collection of the time series traces in the <br />ensemble. <br />6.3.1 Time Series Traces — Comparing Historical and Current Conditions (Input = HydroBase) <br />The following command file illustrates how historical time series traces can be plotted on top of real -time <br />data. The features illustrated in the example were implemented to help determine an estimate of future <br />flow based on current conditions. <br /># StartLog(LogFile= "Example Ensemble.TSTool.log ") <br /># These commands query historical and real -time data at the lobatos gage and <br /># compute a weighted "best- guess" for the flows at lobatos for the remainder <br /># of the current year. In other words, the current year will be complete, <br /># with observed at the beginning and historical "likely" at the end. <br /># First get the historic daily lobatos gage and convert to traces. Shift each trace to <br /># 2008 -01 -01 (the current year) so that the data can overlay the current year's <br /># values. <br />IS daily = readTimeSeries(" 08251500. USGS.Streamflow.Day - HydroBase ") <br />CreateEnsemble(TSID =" daily ",TraceLength =lYear, EnsembleID= "Lobatos ",ReferenceDate= "2008 -01- <br />01" ,ShiftDataHow =ShiftToReference) <br /># Now weight the traces using representative historic years. <br />IS lobatos likely = <br />WeightTraces( EnsembleID =" Lobatos", SpecifyWeightsHow= "AbsoluteWeights ",Weights= "1997,.5,1998,.4, <br />1999,.1 ",NewTSID =" Lobatos ..Streamflow.Day.likely ") <br /># Now query the current (real -time) flows. HydroBase may only hold a few weeks or months <br /># of data. <br /># Uncomment the following line to see the actual real -time values <br /># 08251500 - RIO GRANDE RIVER NEAR LOBATOS <br />08251500. DWR. Streamflow- DISCHRG.Irregular-HydroBase <br /># Convert the irrigular instantaneous values to a daily instantaneous (midnight) <br />IS lobatos = ChangeInterval(TSID="08251500.DWR.Streamflow- <br />DISCHRG.Irregular ",NewInterval= Day, OldTimeScale =INST,NewTimeScale =INST) <br /># Blend the current data to the end of the historical data (the current data <br /># will override. <br />Blend(TSID =" lobatos _current ",IndependentTSID =" lobatos_ likely ",BlendMethod =BlendAtEnd) <br /># After the above commands are executed, time series in memory will include the traces and <br /># the current time series. You can select only the time series of interest and plot <br /># OR select many time series and then disable /enable in the plot. You may need to use <br /># both approaches to find appropriate time series to weight. <br />89 Examples - 9 <br />