dig {nuggets}

Search for rules

Description

This is a general function that enumerates all conditions created from data in x and calls the callback function f on each.

Usage

dig(x, f, ...)

## Default S3 method:
dig(x, f, ...)

## S3 method for class 'matrix'
dig(
  x,
  f,
  condition = everything(),
  focus = NULL,
  disjoint = NULL,
  min_length = 0,
  max_length = Inf,
  min_support = 0,
  t_norm = "goguen",
  ...
)

## S3 method for class 'data.frame'
dig(
  x,
  f,
  condition = everything(),
  focus = NULL,
  disjoint = NULL,
  min_length = 0,
  max_length = Inf,
  min_support = 0,
  t_norm = "goguen",
  ...
)

Arguments

x

a matrix or data frame. The matrix must be numeric (double) or logical. If x is a data frame then each column must be either numeric (double) or logical.

f

the callback function executed for each generated condition. This function may have some of the following arguments. Based on the present arguments, the algorithm would provide information about the generated condition: - condition - a numeric vector of column indices that represent the predicates of the condition. Names of the vector correspond to column names; - foci_supports - a list of support of foci columns (see focus argument to specify, which columns are foci); - support - a numeric scalar value of the current condition's support; - indices - a logical vector indicating the rows satisfying the condition; - weights - (similar to indices) weights of rows to which they satisfy the current condition.

...

Further arguments, currently unused.

condition

a tidyselect expression (see tidyselect syntax) specifying the columns to use as condition predicates

focus

a tidyselect expression (see tidyselect syntax) specifying the columns to use as focus predicates

disjoint

an atomic vector of size equal to the number of columns of x that specifies the groups of predicates: if some elements of the disjoint vector are equal, then the corresponding columns of x will NOT be present together in a single condition.

min_length

the minimum size (the minimum number of predicates) of the condition to be generated (must be greater or equal to 0). If 0, the empty condition is generated in the first place.

max_length

The maximum size (the maximum number of predicates) of the condition to be generated. If equal to Inf, the maximum length of conditions is limited only by the number of available predicates.

min_support

the minimum support of a condition to trigger the callback function for it. The support of the condition is the relative frequency of the condition in the dataset x. For logical data, it equals to the relative frequency of rows such that all condition predicates are TRUE on it. For numerical (double) input, the support is computed as the mean (over all rows) of multiplications of predicate values.

t_norm

a t-norm used to compute conjunction of weights. It must be one of "goedel" (minimum t-norm), "goguen" (product t-norm), or "lukas" (Lukasiewicz t-norm).

Value

A list of results provided by the callback function f.

Author(s)

Michal Burda