Input
  • input
Coefficient set
  • interpolationType
  • extrapolationType
  • inputUnit (optional, since 2016.02)
  • outputUnit (optional, since 2016.02)
  • lookupTable (choice)
    • lookupTableRow
    • locationId / inputParameterId / outputParameterId / qualifierId (since 2017.02)
Output
  • output
Description

 The output will be calculated using a simple table lookup with the input value. The output value will be calculated by interpolation or extrapolation in the lookup table. The type of

interpolation can be configured in the coefficient set with the interpolation type option. The options available are:lineair and logarithmic. When the input value is outside the range

of the lookup table the behaviour of the transformation will be determined by the configured extrapolation type. Make sure the input and output values are configured in ascending order.

 The options available are:

  • notAllowed,
  • maxMin,
  • linear
  • class

 If the first option, notAllowed, is configured an input value outside the range will return a missing value. The second option will return the minimum value or the maximum value in the lookup table. The third option linear enables the extrapolation for the function.

inputUnit: unit of the input values in the lookup table. When this unit is different from the input parameter unit the input values are converted using the config
units configured in the parameters.xml

ouputUnit: unit of the output values in the lookup table. When this unit is different from the output parameter unit the output values are converted using the config

units configured in the parameters.xml

Lookup using table directly specified in transformation config

 

config example lookupTableRow
<transformation id="simpleTableLookup">
	<lookup>
		<simple>
			<input>
				<variableId>H1</variableId>
			</input>
			<coefficientSet>
				<interpolationType>linear</interpolationType>
				<extrapolationType>extrapolate</extrapolationType>
				<inputUnit>m</inputUnit>
				<outputUnit>mm</outputUnit>
				<lookupTable>
					<lookupTableRow input="1.8" output="4000"/>
					<lookupTableRow input="2.0" output="6000"/>
					<lookupTableRow input="2.2" output="8000"/>
					<lookupTableRow input="2.4" output="10000"/>
					<lookupTableRow input="2.6" output="12000"/>
					<lookupTableRow input="2.8" output="14000"/>
					<lookupTableRow input="3.0" output="16000"/>
					<lookupTableRow input="3.2" output="18000"/>
					<lookupTableRow input="3.4" output="20000"/>
					<lookupTableRow input="3.6" output="22000"/>
				</lookupTable>
			</coefficientSet>
			<output>
				<variableId>H2</variableId>
			</output>
		</simple>
	</lookup>
</transformation>

In case of class interpolation we look at which input threshold (lower or higher) the value is closest to, and the output responding to that threshold will be the output.  Using the example below it mean for an input 0 the output will be 0, for input 160 output will be 2, for input 499 output will be 5. When the input falls exactly between the two thresholds, it will be rounded up, so for input 500 the output will be 6.

class interpolation
<transformation id="ClassInterpolation">
	<lookup>
		<simple>
			<input>
				<variableId>variable1</variableId>
			</input>
			<coefficientSet>
				<interpolationType>class</interpolationType>
				<extrapolationType>extrapolate</extrapolationType>
				<lookupTable>
					<lookupTableRow input="0" output="0"/>
					<lookupTableRow input="10" output="1"/>
					<lookupTableRow input="150" output="2"/>
					<lookupTableRow input="250" output="3"/>
					<lookupTableRow input="350" output="4"/>
					<lookupTableRow input="450" output="5"/>
					<lookupTableRow input="550" output="6"/>
				</lookupTable>
			</coefficientSet>
			<output>
				<variableId>variable2</variableId>
			</output>
		</simple>
	</lookup>
Lookup using LookupTables.xml from RegionConfigFiles

 

Since 2017.02 it is possible to use LookupTables.xml from RegionConfig by referencing with locationId, inputParameterId & outputParameterId

config example lookup from LookupTables.xml in RegionConfig
<transformation id="simpleTableLookup">
	<lookup>
		<simple>
			<input>
				<variableId>H1</variableId>
			</input>
			<coefficientSet>
				<interpolationType>linear</interpolationType>
				<extrapolationType>extrapolate</extrapolationType>
				<lookupTable>
					<piTable>
						<locationId>H-2002</locationId>
						<inputParameterId>H.m</inputParameterId>
						<outputParameterId>H.obs</outputParameterId>
					</piTable>
				</lookupTable>
			</coefficientSet>
			<output>
				<variableId>H2</variableId>
			</output>
		</simple>
	</lookup>
</transformation>

Example LookupTables.xml from RegionConfig

Example LookupTables.xml from RegionConfig
<?xml version="1.0" encoding="UTF-8"?>
<Tables xmlns="http://www.wldelft.nl/fews/PI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://www.wldelft.nl/fews/PI http://fews.wldelft.nl/schemas/version1.0/pi-schemas/pi_tables.xsd">
   <table>
      <header>
         <locationId>H-2002</locationId>
         <a parameterId="H.m" units="m"/>
         <b parameterId="H.obs" units="m"/>
         <startDate date="2012-01-01" time="00:00:00"/>
      </header>
      <table>
         <row a="99" b="122.566570633982"/>
         <row a="158" b="216.30059062327"/>
         <row a="160" b="218.698850750015"/>
         <row a="162" b="221.058958199806"/>
         <row a="164" b="223.381719470149"/>
         <row a="166" b="225.667911902593"/>
         <row a="168" b="227.91859175558"/>
         <row a="170" b="230.884412887021"/>
         <row a="172" b="233.920464645294"/>
         <row a="174" b="237.492498877315"/>
      </table>
   </table>
</Tables>

When 'b' needs to be looked up by 'a' ->

<locationId> of the PiTable
<inputParameterId1> => 'a'
<outputParameterId> => 'b'

  • No labels

Disclaimer