dvmisc (version 1.1.4)

which_min_nm: Return (Row, Column) Index of (First) Minimum of a Numeric Matrix

Description

Written in C++, this function tends to run much faster than the equivalent (if minimum is unique) base R solution which(x == min(x), arr.ind = TRUE).

Usage

which_min_nm(x)

Arguments

x

Numeric matrix.

Value

Integer vector.

Details

For optimal speed, choose the version of this function that matches the class of your x:

which_min_nv for numeric vector. which_min_iv for integer vector. which_min_nm for numeric matrix. which_min_im for integer matrix.

Examples

# NOT RUN {
# which_min_nm is typically much faster than 
# which(x == min(x), arr.ind = TRUE)
x <- matrix(rnorm(100), ncol = 10)
all(which(x == min(x), arr.ind = TRUE) == which_min_nm(x))
benchmark(which(x == min(x), arr.ind = TRUE), which_min_nm(x), 
          replications = 5000)

# }