The gridded table definition element
Prev Schematic overview of DAVEfunc Next

The gridded table definition element

The griddedTableDef element defines a multi-dimensional table of values corresponding with the value of an arbitrary function at the intersection of a set of specified independent inputs. The coordinates along each dimension are defined in separate breakpointDef elements that are referenced within this element by bpRefs, one for each dimension.

The data contained within the data table definition are a comma-separated set of floating-point values. This list of values represents a multidimensional array whose size is inferred from the length of each breakpoint vector. For example, a two-dimensional table that is a function of an eight-element Mach breakpoint set and a ten-element angle-of-attack breakpoint set is expected to contain 80 comma-separated values.

By convention, the breakpointRefs are listed in order such that the last breakpoint set varies most rapidly in the associated data table listing.

An optional uncertainty element may be provided that represents the statistical variation in the values presented. See the section on Statistics below for more information about this element. 

    griddedTableDef* : [gtID, name, units]
        description? :
            (description character data)
        provenance? :
            author : name, org, [email]
                address? :
                    (address character data)
            functionCreationDate :
                (date in YYYY-MM-DD format, character data)
            documentRef* : docID
            modificationRef* : modID
        breakpointRefs :
          bpRef+ : bpID
        uncertainty? : effect
            (normalPDF : numSigmas | uniformPDF : symmetry )
        dataTable
          (character data)

griddedTableDef attributes:

gtID

An XML-legal name that is unique within the file.

name

A UNICODE name for the table (may be same as gtID).

units

The units-of-measure for the table's output signal. See the section on Conventions below.

griddedTableDef sub-elements:

description

The optional description element allows the author to describe the data contained within this griddedTable.

provenance

The optional provenance element allows the author to describe the source and history of the data within this griddedTable.

breakpointRefs

The mandatory breakpointRefs element contains separate bpRef elements, each pointing to a separately-defined breakpointDef. Thus, the independent coordinates associated with this function table are defined elsewhere and only a reference is given here. The order of appearance of the bpRefs is important; see the text above.

uncertainty

This optional element, if present, describes the uncertainty of this parameter. See the section on Statistics below for more information about this element.

dataTable

The numeric values of the function at the function vertices specified by the breakpoint sets are contained within this element, in a single comma-separated list. Parsing this list and storing it in the appropriate array representation is up to the implementor. By convention, the last breakpoint value increases most rapidly.

Example 8. An example of a griddedTableDef element

This non-linear function table is used by a subsequent function in example 9 to specify an output value based on two inputs values - body flap deflection and Mach number. This table is defined outside of a function element because this particular function table is used by two functions - one for the left lower body flap and one for the right lower body flap; thus, their actual independent (input) variable values might be different. 

        <!-- ==================================== -->     1
        <!-- Lower Body Flap Tables (definitions) -->
        <!-- ==================================== -->

  <griddedTableDef name="CLBFL0" gtID="CLBFL0_table">     2
    <description>      3
        Lower body flap contribution to lift coefficient,
        polynomial constant term
    </description>
    <provenance>        4
      <author name="Bruce Jackson" org="NASA Langley Research Center" email="[email protected]"/>
      <functionCreationDate date="2003-01-31"/>
      <documentRef docID="REF01"/>
    </provenance>
    <breakpointRefs> 5
      <bpRef bpID="DBFL_PTS"/>
      <bpRef bpID="XMACH1_PTS"/>
    </breakpointRefs>
    <dataTable> <!-- last breakpoint changes most rapidly --> 6
<!-- CLBFL0 POINTS  -->
<!-- DBFL =        0.0       -->
 0.00000E+00 , 0.00000E+00 , 0.00000E+00 , 0.00000E+00 , 0.00000E+00 ,
 0.00000E+00 , 0.00000E+00 , 0.00000E+00 , 0.00000E+00 , 0.00000E+00 ,
 0.00000E+00 , 0.00000E+00 , 0.00000E+00 ,
<!-- DBFL =       15.0       --> 7
-0.86429E-02 ,-0.10256E-01 ,-0.11189E-01 ,-0.12121E-01 ,-0.13520E-01 ,
-0.86299E-02 ,-0.53679E-02 , 0.76757E-02 , 0.11300E-01 , 0.62992E-02 ,
 0.51902E-02 , 0.38813E-02 , 0.37366E-02 ,
<!-- DBFL =       30.0       -->
 0.22251E-01 , 0.26405E-01 , 0.28805E-01 , 0.31206E-01 , 0.34806E-01 ,
 0.31321E-01 , 0.28996E-01 , 0.19698E-01 , 0.18808E-01 , 0.12755E-01 ,
 0.10804E-01 , 0.98493E-02 , 0.83719E-02 ,
<!-- DBFL =       45.0       -->
 0.29416E-01 , 0.34907E-01 , 0.38080E-01 , 0.41254E-01 , 0.46014E-01 ,
 0.42215E-01 , 0.39681E-01 , 0.29547E-01 , 0.28211E-01 , 0.19132E-01 ,
 0.16206E-01 , 0.14774E-01 , 0.12558E-01 ,
<!-- DBFL =       60.0       -->
 0.63779E-01 , 0.75685E-01 , 0.82566E-01 , 0.89446E-01 , 0.99767E-01 ,
 0.85587E-01 , 0.76127E-01 , 0.38301E-01 , 0.36569E-01 , 0.24800E-01 ,
 0.21007E-01 , 0.19151E-01 , 0.16278E-01
    </dataTable>
  </griddedTableDef>
1

Comments are a good idea for human readers

2

name is used for documentation purposes; gtID is intended for automatic wiring (autocode) tools.

3

Descriptions are a good idea whenever possible - Here we explain the contents of the function represented by the data points.

4

provenance is the story of the origin of the data.

5

These bpRefs are in the same order as the table is wrapped (see text above) and must be reflected in the referencing function in the same order. In this example, the referencing function must list the independentVarRefs such that the signal that represents delta body flap (DBFL) must precede the reference to the signal that represents Mach number (XMACH).

6

The points listed within the dataTable element are given as if the last bpRef varies most rapidly. See the discussion above.

7

Embedded comments are a good idea.


Prev Up Next
The breakpoint set definition element Home | ToC The ungridded table definition element