maxCol {base}R Documentation

Find Maximum Position in Matrix

Description

Find the maximum position for each row of a matrix, breaking ties at random.

Usage

max.col(m)

Arguments

m numerical matrix

Details

Ties are broken at random. The determination of “tie” assumes that the entries are probabilities: there is a relative tolerance of 1e-5, relative to the largest entry in the row.

Value

index of a maximal value for each row, an integer vector of length nrow(m).

References

Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. New York: Springer (4th ed).

See Also

which.max for vectors.

Examples

data(swiss)
table(mc <- max.col(swiss))# mostly "1" and "5", 5 x "2" and once "4"
swiss[unique(print(mr <- max.col(t(swiss)))) , ] # 3 33 45 45 33 6

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