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TSTool / Command / ChangeIntervalIrregularToRegular

Overview

The ChangeIntervalIrregularToRegular command creates a new regular interval time series (or ensemble) from an irregular interval time series (or ensemble). This command is under development and is intended to provide a simpler subset of functionality compared to the more complicated ChangeInterval command, which was developed for advanced hydrologic data processing but can be complicated to use.

A list of one or more time series or an ensemble of time series can be processed. The majority of the original header data (e.g., description, units) are copied to the new time series; however, the new interval will be used in the new time series identifier.

Irregular interval time series with interval Irreg or Irregular rely on the date/time precision indicated by the date/times from the original data source. Irregular interval time series with interval IrregMinute, for example, should have date/times with precision minute.

Time zone in input irregular time series is ignored for processing. Any time zone shift necessary to ensure that days align at midnight must occur prior to this command.

Example: Real-time to 1Hour for Event-Focused Data Management System

An event-focused data management system collects data at periodic regular intervals (e.g., every 12 hours) and when an event occurs that results in changing data values. Conversion of real-time irregular interval data to larger regular interval is as follows, using second-precision input and 1Hour output as an example, with Statistic=Mean. In the following diagram, (1), (2), (3), and (4) indicate sensor measurements.

       |                          PersistInterval=1Hour                                 |
       |                      /--------------------------/   |                          |
      (1)      (2)    (3)    (4)  |                          |                          |
       |                          |                          |                          |
  YYYY-MM-DD 00            YYYY-MM-DD 01              YYYY-MM-DD 02              YYYY-MM-DD 03
  1. For interval ending YYYY-MM-DD 01:
    1. The sample is determined as data values 2, 3, and 4. The sample does not include value 1 because the output interval spans the time: > YYYY-MM-DD 00 and <= YYYY-MM-DD 01
    2. The output value is computed as the mean of values 1, 2, and 3.
  2. For interval ending YYYY-MM-DD 02:
    1. The sample has no values.
    2. However, because the PersistInterval is 1Hour, the last value 4 within the PersistInterval is used as the single sample value and in this case is also the mean value. If PersistValue=0, then an input value of 0 would be used, which is suitable for data types such as precipitation increment.
  3. For interval ending YYYY-MM-DD 03:
    1. The sample has no values.
    2. The output value is missing since a value cannot be determined from the sample or PersistInterval.

Command Editor

The command is available in the following TSTool menu:

  • Commands / Create Time Series

The following dialog is used to edit the command and illustrates the syntax for the command.

ChangeIntervalIrregularToRegular command editor for Input parameters

ChangeIntervalIrregularToRegular Command Editor for Input Parameters (see full-size image)

ChangeIntervalIrregularToRegular command editor for Analysis to larger Parameters

ChangeIntervalIrregularToRegular Command Editor for Analysis (to Larger) Parameters (see full-size image)

ChangeIntervalIrregularToRegular command editor for analysis to smaller parameters

ChangeIntervalIrregularToRegular Command Editor for Analysis (to Smaller) Parameters (see full-size image)

ChangeIntervalIrregularToRegular command editor for output parameters

ChangeIntervalIrregularToRegular Command Editor for Output Parameters (see full-size image)

ChangeIntervalIrregularToRegular command editor for ensemble output parameters

ChangeIntervalIrregularToRegular Command Editor for Ensemble Output Parameters (see full-size image)

Command Syntax

The command syntax is as follows:

ChangeIntervalIrregularToRegular(Parameter=Value,...)

Command Parameters

Parameter Group Parameter                                Description Default                           
Input TSList Indicates the list of time series to be processed, one of:
  • AllMatchingTSID – all time series that match the TSID (single TSID or TSID with wildcards)
  • AllTS – all time series generated before the command
  • EnsembleID – all time series in the ensemble
  • FirstMatchingTSID – the first time series that matches the TSID (single TSID or TSID with wildcards)
  • LastMatchingTSID – the last time series that matches the TSID (single TSID or TSID with wildcards)
  • SelectedTS – the time series selected with the SelectTimeSeries command
 AllTS
Input TSID The time series identifier or alias for the time series to be processed, using the * wildcard character to match multiple time series. Can be specified using processor ${Property}. Required if TSList=*TSID.
Input EnsembleID The ensemble to be processed, if processing an ensemble. Can be specified using processor ${Property}. Required if TSList=EnsembleID.
Analysis (to Larger)
 Statistic
required		 Statistic to compute to convert sample of input time series values to output value, when converting smaller date/time precision units to larger interval. See the table below for supported statistics. None - must be specified.
Analysis (to Larger)
 Flag
 Flag to use for values that are calculated. Flag won't be set.
Analysis (to Larger)
 FlagDescription
 Description for Flag.
Analysis (to Larger) PersistInterval The interval after a non-missing value within which the value can be used to fill output values. This is used in data collection systems where data values are available only for periodic regular reports (e.g., every 12 hours) and when an event is occurring. Specify using an interval string consistent with time series identifier data interval, such as 15Minute, 1Hour, Day, Month, or Year. The PersistInterval is added to the last observation time and is considered as the input data value if the resulting date/time is within the output interval. Data do not persist past actual observations.
Analysis (to Larger) PersistValue The value to use in the PersistInterval when no sample values are found. For example specify 0 for precipitation increment time series (otherwise the last precipitation increment will be erroneously used). Last input time series value.
Analysis (to Larger)
 PersistFlag
 Flag to use for values that are set in the PersistInterval. Flag won't be set.
Analysis (to Larger)
 PersistFlagDescription
 Description for PersistFlag.
Analysis (to Smaller) SampleMethod This parameter is envisioned for the future and would indicate how to determine the smaller interval output from irregular interval values for larger date/time units. Not currently implemented.
Output Alias
required		 The alias to assign to the time series, as a literal string or using the special formatting characters listed by the command editor. The alias is a short identifier used by other commands to locate time series for processing, as an alternative to the time series identifier (TSID). None – must be specified.
Output NewInterval
required		 The data interval for the new time series, from the provided choices. For example: 6Hour, Day, Month, Year. None – must be specified.
Output OutputYearType The output year type if the output time series has an interval of Year. Calendar
Output NewDataType The data type for the new time series. This will be set in the identifier of the new time series. Use the data type from the original time series.
Output NewUnits The units for the new time series. This will be set in the identifier of the new time series. Use the units from the original time series.
Output ScaleValue Value to scale output values, used to convert units. Do not scale output values.
Output OutputStart Start date/time for output time series. Not yet implemented.. Determine from input time series.
Output OutputEnd End date/time for output time series. Not yet implemented.. Determine from input time series.
Output RecalcLimits Whether to recalculate the time series limits. Do not scale output values.
Output (Ensemble) NewEnsembleID New ensemble identifier, if processing an input ensemble.
Output (Ensemble) NewEnsembleName New ensemble name, if processing an input ensemble.

The following statistics can be used to compute the interval data using the Statistic parameter.

Supported Statistics

Statistic Description
Max Maximum of sample values.
Mean Mean of sample values.
Median Median of sample values.
Min Minimum of sample values.

Examples

See the automated tests.

Troubleshooting

See the main TSTool Troubleshooting documentation.

See Also