marginSums {base}

R Documentation

Compute Table Margins

Description

For a contingency table in array form, compute the sum of table entries for a given margin or set of margins.

Usage

marginSums(x, margin = NULL)
margin.table(x, margin = NULL)

Arguments

x	an array, usually a table.
margin	a vector giving the margins to compute sums for. E.g., for a matrix 1 indicates rows, 2 indicates columns, c(1, 2) indicates rows and columns. When x has named dimnames, it can be a character vector selecting dimension names.

Value

The relevant marginal table, or just the sum of all entries if margin has length zero. The class of x is copied to the output table if margin is non-NULL.

Note

margin.table is an earlier name, retained for back-compatibility.

Author(s)

Peter Dalgaard

See Also

rowSums and colSums for similar functionality.

proportions and addmargins.

Examples

m <- matrix(1:4, 2)
marginSums(m, 1)  # = rowSums(m)
marginSums(m, 2)  # = colSums(m)

DF <- as.data.frame(UCBAdmissions)
tbl <- xtabs(Freq ~ Gender + Admit, DF)
tbl
marginSums(tbl, "Gender")  # a 1-dim "table"
rowSums(tbl)               # a numeric vector

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