Data Filters (filter
)¶
Instances of classes derived from Filter are used for filtering the data.
When called with an individual data instance (Orange.data.Instance
),
they accept or reject the instance by returning either True or False.
When called with a data storage (e.g. an instance of
Orange.data.Table
) they check whether the corresponding class
provides the method that implements the particular filter. If so, the
method is called and the result should be of the same type as the
storage; e.g., filter methods of Orange.data.Table
return new
instances of Orange.data.Table
, and filter methods of SQL proxies
return new SQL proxies.
If the class corresponding to the storage does not implement a particular filter, the fallback computes the indices of the rows to be selected and returns data[indices].
- class Orange.data.filter.IsDefined(columns=None, negate=False)[source]¶
Select the data instances with no undefined values. The check can be restricted to a subset of columns.
The filter's behaviour may depend upon the storage implementation.
In particular,
Table
with sparse matrix representation will select all data instances whose values are defined, even if they are zero. However, if individual columns are checked, it will select all rows with non-zero entries for this columns, disregarding whether they are stored as zero or omitted.- columns¶
The columns to be checked, given as a sequence of indices, names or
Orange.data.Variable
.
- class Orange.data.filter.HasClass(negate=False)[source]¶
Return all rows for which the class value is known.
Orange.data.Table
implements the filter on the sparse data so that it returns all rows for which all class values are defined, even if they equal zero.
- class Orange.data.filter.Random(prob=None, negate=False)[source]¶
Return a random selection of data instances.
- prob¶
The proportion (if below 1) or the probability (if 1 or above) of selected instances
- class Orange.data.filter.SameValue(column, value, negate=False)[source]¶
Return the data instances with the given value in the specified column.
- column¶
The column, described by an index, a string or
Orange.data.Variable
.
- value¶
The reference value
- class Orange.data.filter.Values(conditions, conjunction=True, negate=False)[source]¶
Select the data instances based on conjunction or disjunction of filters derived from
ValueFilter
that check values of individual features or another (nested) Values filter.- conjunction¶
If True, the filter computes a conjunction, otherwise a disjunction
- negate¶
Revert the selection
- class Orange.data.filter.FilterDiscrete(column, values)[source]¶
Subfilter for discrete variables, which selects the instances whose value matches one of the given values.
- column¶
The column to which the filter applies (int, str or
Orange.data.Variable
).
- values¶
The list (or a set) of accepted values. If None, it checks whether the value is defined.
- class Orange.data.filter.FilterContinuous(position, oper, ref=None, max=None, min=None)[source]¶
Subfilter for continuous variables.
- column¶
The column to which the filter applies (int, str or
Orange.data.Variable
).
- ref¶
The reference value; also aliased to min for operators Between and Outside.
- max¶
The upper threshold for operators Between and Outside.
- oper¶
The operator; should be FilterContinuous.Equal, NotEqual, Less, LessEqual, Greater, GreaterEqual, Between, Outside or IsDefined.
- Type¶
alias of
FilterContinuous
- class Orange.data.filter.FilterString(position, oper, ref=None, max=None, case_sensitive=True, **a)[source]¶
Subfilter for string variables.
- column¶
The column to which the filter applies (int, str or
Orange.data.Variable
).
- ref¶
The reference value; also aliased to min for operators Between and Outside.
- max¶
The upper threshold for operators Between and Outside.
- oper¶
The operator; should be FilterString.Equal, NotEqual, Less, LessEqual, Greater, GreaterEqual, Between, Outside, Contains, StartsWith, EndsWith or IsDefined.
- case_sensitive¶
Tells whether the comparisons are case sensitive
- Type¶
alias of
FilterString
- class Orange.data.filter.FilterStringList(column, values, case_sensitive=True)[source]¶
Subfilter for strings variables which checks whether the value is in the given list of accepted values.
- column¶
The column to which the filter applies (int, str or
Orange.data.Variable
).
- values¶
The list (or a set) of accepted values.
- case_sensitive¶
Tells whether the comparisons are case sensitive