Data Preparation Rules

DataGrid

Structure(DataGrid) DataGrid(Structure(Partition) partition1, ..., Structure(Frequencies))

Builds a DataGrid structure.

The first parameters are partitions: the results of the rules IntervalBounds, ValueGroups, ValueSetC or ValueSet. The last argument are the data grid cell frequencies.

Example

The following contingency table (a two-dimensional data grid)

Interval	Iris-setosa	Iris-versicolor	Iris-virginica
]-inf;0.75]	38	0	0
]0.75;1.55]	0	33	0
]1.55;+inf[	0	3	34

is encoded in a dictionary using a constructed variable:

Dictionary Example
{
  Structure(DataGrid) PPetalWidth = DataGrid(
    IntervalBounds(0.75, 1.55),
    ValueSetC("Iris-setosa", "Iris-versicolor", "Iris-virginica"),
    Frequencies(38, 0, 0, 0, 33, 3, 0, 0, 34)
  );
};

The cells are indexed column-first. In this example, contingency table indexation is as follows:

Interval	Iris-setosa	Iris-versicolor	Iris-virginica
]-inf;0.75]	1	4	7
]0.75;1.55]	2	5	8
]1.55;+inf]	3	6	9

Several derivation rules use a data grid structure to retrieve a cell given a vector of input values. For example, the vector of values (1.1, "Iris-versicolor") falls into the cell of index 5.

The value vector can be partially complete. In this case, the other dimension has default values corresponding to the first part of their dimension. For example, the single value vector (1.1) falls into the cell of index 2.

The value types can be either Numerical or Categorical according to the data grid input partition types. In the following, this will be indicated using SimpleType for such parameter types.

IntervalBounds

Structure(IntervalBounds) IntervalBounds(Numerical bound1, ...)

Builds a partition into interval.

ValueGroup

Structure(ValueGroup) ValueGroup(Categorical value1, ...)

Builds a group of values. The special value * cannot correspond to a value extracted from datasets (these ones are trimmed before being processed). This special value can be used as a "garbage value" to match any value that are not explicitly defined elsewhere.

ValueGroups

Structure(ValueGroups) ValueGroups(Structure(ValueGroup) valueGroup1, ...)

Builds a partition into groups of values. The special value * must be defined in exactly one value group, which is assigned to unknown values.

ValueSetC

Structure(ValueSetC) ValueSetC(Categorical value1, ...)

Builds a partition into categorical values.

ValueSet

Structure(ValueSet) ValueSet(Numerical value1, ...)

Builds a partition into numerical values.

Frequencies

Structure(Frequencies) Frequencies(Numerical frequency1, ...)

Builds a vector of frequencies.