truthTable: Create a truth table

Description

For any number of conditions, there is a finite number of possible combinations of presence/absence. truthTable() finds the observed combinations among all possible ones, prints the frequency of each observed combination and establishes the value for the outcome in this way: - if all observed combinations agree on having the same outcome value (either 0 or 1), then the value for the outcome will be set to that value - for any given combination, if the outcome present values of both 0 and 1 then the value for the outcome will be set to a contradiction ("C") - for all other possible combinations, the outcome is missing and will be coded with "?" is.tt() checkes if an object has the class tt (if it is a truth table); such an object is created by truthTable() print.tt() has an S3 method for printing objects of class 'tt'

Usage

truthTable(mydata, outcome = "", conditions = c(""), complete = FALSE,
           show.cases = FALSE, quiet = FALSE)
is.tt(x)
## S3 method for class 'tt':
print(x, funqmcc=FALSE, ...)

Arguments

mydata

the dataset we use for minimization

outcome

the name of the outcome variable in the dataset

conditions

the name of the conditions from the dataset (if not specified, all variables but the outcome are considered conditions)

quiet

if TRUE, return the truth table invisibly

show.cases

show the rownames from the original dataset for each combination of conditions

complete

prints the complete truth table, including the missing combinations

an object of class tt

funqmcc

logical, if called by (e)qmcc() function(s) it prints only the observed combinations from the initial data

...

other arguments from the generic print (not used in this function)

Value

An object of class "tt", which is essentially a list with three components: ll{ $tt: the truth table itself $indexes: a vector with the base 10 representation of the truth table observed combinations $noflevels: a vector with the number of levels from all input variables }

References

Ragin, Charles C. (1987) The Comparative Method. Moving beyond qualitative and quantitative strategies, Berkeley: University of California Press

Examples

Run this code

data(Osa)

# print the truth table
truthTable(Osa, outcome="OUT", show.cases=TRUE)

# print the complete truth table
truthTable(Osa, outcome="OUT", complete=TRUE, show.cases=TRUE)

# save the result into an R object:
mytable <- truthTable(Osa, outcome="OUT", complete=TRUE, show.cases=TRUE, quiet=TRUE)

mytable # or print.tt(mytable)

# check the components

mytable$tt # the truth table itself

mytable$indexes # base 10 representation of input combinations

mytable$noflevels # number of levels from each causal condition