6.2.7. The checkData element

The checkData element contains one or more input/output vector pairs (and optionally a dump of internal values) for the encoded model to assist in verification and debugging of the implementation.

    checkData
      staticShot+ : name, [refID]
            description?
                {text description of the static test case}
                    (provenance | provenanceRef)?   {as defined previously}
            checkInputs
                signal+
                    signalName
                    signalUnits
                    signalValue
            internalValues?
                signal+
                    varID 
                    signalValue
            checkOutputs
                signal+
                    signalName
                    signalUnits
                    signalValue
                    tol

        

checkData sub-elements:

staticShot

One or more check-case data sets, each of which contain mandatory sub-elements checkInputs and checkOutputs vectors (with required match tolerances), and optional provenance, provenanceRef, description and internalValues sub-elements.

Example 14. Check-case data set excerpt

A DAVE-ML file excerpt specifying a check-case data set example for a simple model

  <checkData>
    <staticShot name="Nominal" refID="NOTE1"> 1
      <description>An example static check of a simple DAVE-ML model</description>
      <checkInputs>  2
        <signal>  3
          <signalName>trueAirspeed</signalName>
          <signalUnits>f_s</signalUnits>
          <signalValue> 300.000</signalValue>
        </signal>
        <signal> 
          <signalName>angleOfAttack</signalName>
          <signalUnits>deg</signalUnits>
          <signalValue>   5.000</signalValue>
        </signal>
         .
         .       (similar input signals omitted)
         .
        <signal>
          <signalName>delta elevator</signalName> 
          <signalUnits>deg</signalUnits>
          <signalValue>   0.000</signalValue>
        </signal>
      </checkInputs>
      <checkOutputs> 4
        <signal>  5
          <signalName>CX</signalName>
          <signalUnits>nd</signalUnits>
          <signalValue>-0.00400000000000</signalValue>
          <tol>0.000001</tol>
        </signal>
         .
         .       (similar output signals omitted)
         .
      </checkOutputs>
    </staticShot>
    <staticShot name="Positive pitch rate"> 6
      <checkInputs> 
         .
         .       (similar input and output signal information omitted)
         .
      </checkOutputs>
    </staticShot>
    <staticShot name="Positive elevator">
      <checkInputs> 
         .
         .       (similar input and output signal information omitted)
         .
      </checkOutputs>
    </staticShot>
  </checkData>
          
1

This first check-case refers to a note given in the file header; this is useful to document the source of the check-case values.

2

The checkInputs element defines the input variable values, by variable name, as well as units (so they can be verified).

3

Multiple signal elements are usually given; taken together, these scalar signalss represent the check-case input "vector."

4

The checkOutputs element defines output variable values that should result from the specified input values.

5

Note the included tolerance value, indicating the absolute value tolerance within which the output values must match the check-case data values.

6

Multiple check-cases may be specified; this one differs from the previous check-case due to an increase in the pitching-rate input.


Example 15. A second checkData example with internal values

This example shows another check-case; this one includes intermediate values as an aide to debugging a new implementation.

  <checkData>
    <( provenance | provenanceRef )?>
    <staticShot name="Skewed inputs">
      <description>
        Another example static check; this one includes all the internal, intermediate calculations
        to assist in debugging the implementation.
      </description>
      <checkInputs> 
        <signal> 
          <signalName>trueAirspeed</signalName>
          <signalUnits>f_s</signalUnits>\
          <signalValue> 300.000</signalValue>
        </signal>
        <signal>
          <signalName>angleOfAttack</signalName>
          <signalUnits>deg</signalUnits>
          <signalValue>  16.200</signalValue>
        </signal>
         .
         .       (similar input values omitted)
         .
        <signal>
          <signalName>bodyPositionOfCmWrtMrc</signalName>
          <signalUnits>fracMAC</signalUnits>
          <signalValue>   0.123</signalValue>
        </signal>
      </checkInputs>
      <internalValues> 1
        <signal>
          <varID>vt</varID>
          <signalValue>300.0</signalValue>
        </signal>
        <signal>
          <varID>alpha</varID>
          <signalValue>16.2</signalValue>
        </signal>
         .
         .       (similar internal values omitted)
         .
      </internalValues>
      <checkOutputs>
        <signal>
          <signalName>aeroBodyForceCoefficient_X</signalName>
          <signalValue> 0.04794994533333</signalValue>
          <signalUnits>nd</signalUnits>
          <tol>0.000001</tol>
        </signal>
        <signal>
          <signalName>aeroBodyForceCoefficient_Z</signalName>
          <signalValue>-0.72934852554344</signalValue>
          <signalUnits>nd</signalUnits>
          <tol>0.000001</tol>
        </signal>
        <signal>
          <signalName>aeroBodyMomentCoefficient_Pitch</signalName>
          <signalValue>-0.10638585796503</signalValue>
          <signalUnits>nd</signalUnits>
          <tol>0.000001</tol>
        </signal>
      </checkOutputs>
    </staticShot>
  </checkData>
            
          
1

The internalValues element, if present, usually is a list of all model-defined internal variable values. This is normally not required for a model exchange, but such information is very useful to aide in debugging the implementation by the recipient.


2011-03-31