ctab: ctab Cross Tabulation (table outputs)

In tdisplay: Tool Box for Data Importation and Display

Description

The function builds contingency tables: counts and row proportions. When right-hand side formula contains more than 1 variable, ctab builds successive two-way tables, vertically and with same column-variable.

Three types of data are managed by ctab:

• Split individual data;

• Grouped data with weights;

• Grouped data of form “cbind(success, failure)”.

For grouped data, ctab uses splitbin.

Usage

  ctab(formula, data, weights = NULL, digits = 2)
  ## S3 method for class 'ctab'
print(x, ...)
  

Arguments

formula	A 2-sided formula describing the contincency table. The left-hand side represents the column-variable. See examples for syntax.
data	A data frame where formula is evaluated.
weights	Variable representing the weight for grouped data with weights.
digits	A scalar indicating the number of decimal digits left when rounding the result of the statictics.
x	An object of class “ctab”.
...	Further arguments to be passed to the functions.

Value

A list with components CALL, formula, f, tab, tab.counts, tab.p, counts and digits. Component tab is the basic contingency table. Component counts is the corresponding data frame (grouped data with weights).

See Also

table, xtabs, ftable

Examples

#=== Example of the 3 types of data managed by ctab

    # Split data

tmp <- data.frame(
    treatment = c("B", "A", "C", "C", "B", "B", "C", "A", "B", "B", NA, "C"),
    surv = c("YES", "NO", "YES", "YES", "NO", "NO", "NO", "YES", "YES", "NO", "NO", NA)
    )
#tmp$treatment <- factor(tmp$treatment, levels = c("C", "A", "B"))
tmp

ctab(formula = surv ~ 1, data = tmp)
ctab(formula = surv ~ treatment, data = tmp, digits = 1)

    # Grouped data with weights

tmp <- data.frame(
    treatment = c("A", "B", "C", "A", "B", "C", NA, "C"),
    surv = c("NO", "NO", "NO", "YES", "YES", "YES", "NO", NA),
    n = c(1, 3, 1, 1, 2, 2, 1, 1)
    )
tmp

ctab(formula = surv ~ 1, data = tmp, weights = n)
ctab(formula = surv ~ treatment, data = tmp, weights = n)

    # Grouped data of the form "cbind(success, failure)"

tmp <- data.frame(
    treatment = c("A", "B", "C", NA),
    surv = c(1, 2, 2, 0),
    death = c(1, 3, 1, 1)
    )
tmp

ctab(formula = cbind(surv, death) ~ 1, data = tmp)
ctab(formula = cbind(surv, death) ~ treatment, data = tmp)

#=== Examples of tables

n <- 80
tmp <- data.frame(
    y1 = sample(1:2, n, replace = TRUE),
    y2 = sample(1:2, n, replace = TRUE),
    y3 = sample(1:3, n, replace = TRUE),
    y4 = sample(1:4, n, replace = TRUE)
    )
head(tmp)
ctab(formula = y3 ~ 1, data = tmp)

res <- ctab(formula = y3 ~ y1, data = tmp)
res$tab
res$tab.p

ctab(formula = y3 ~ y1 + y2, data = tmp)
ctab(formula = y3 ~ y1 + y2 + y4, data = tmp)

    

tdisplay documentation built on May 2, 2019, 4:46 p.m.