interval_stats: Statistics for Interval Data

In dataSDA: Datasets and Basic Statistics for Symbolic Data Analysis

Statistics for Interval Data

Description

Functions to compute the mean, variance, covariance, and correlation of interval-valued data.

Usage

int_mean(x, var_name, method = "CM", ...)

int_var(x, var_name, method = "CM", ...)

int_cov(x, var_name1, var_name2, method = "CM", ...)

int_cor(x, var_name1, var_name2, method = "CM", ...)

Arguments

x	interval-valued data with symbolic_tbl class.
var_name	the variable name or the column location (multiple variables are allowed).
method	methods to calculate statistics: CM (default), VM, QM, SE, FV, EJD, GQ, SPT.
...	additional parameters
var_name1	the variable name or the column location (multiple variables are allowed).
var_name2	the variable name or the column location (multiple variables are allowed).

Details

Available methods (applicable to all four functions):

• CM: Center Method — uses midpoints (a + b) / 2

• VM: Vertices Method — uses all 2^p vertex combinations

• QM: Quantiles Method — uses equally spaced quantile points

• SE: Set Expansion — uses endpoints only (quantiles with m = 1)

• FV: Fitted Values — uses linear regression fitted values

• EJD: Empirical Joint Distribution

• GQ: Symbolic Covariance method (Billard and Diday, 2006)

• SPT: Total Sum of Products (Billard, 2008)

Value

A numeric matrix for int_mean and int_var (methods x variables); a named list of covariance/correlation matrices for int_cov and int_cor (one matrix per method).

Author(s)

Han-Ming Wu

See Also

int_mean int_var int_cov int_cor

Examples

data(mushroom.int)
int_mean(mushroom.int, var_name = "Pileus.Cap.Width")
int_mean(mushroom.int, var_name = 2:3)

var_name <- c("Stipe.Length", "Stipe.Thickness")
method <- c("CM", "FV", "EJD")
int_mean(mushroom.int, var_name, method)
int_var(mushroom.int, var_name, method)

var_name1 <- "Pileus.Cap.Width"
var_name2 <- c("Stipe.Length", "Stipe.Thickness")
method <- c("CM", "VM", "EJD", "GQ", "SPT")
int_cov(mushroom.int, var_name1, var_name2, method)
int_cor(mushroom.int, var_name1, var_name2, method)

dataSDA documentation built on June 12, 2026, 9:06 a.m.