Copy a vector into a matrix

Creates a matrix by stacking multiple copies of a vector as rows (rowCopy) or as columns (colCopy).

Usage

colCopy(x, times, dimnames = NULL)

rowCopy(x, times, dimnames = NULL)

Arguments

x

A vector to be copied.

times

The number of copies to stack together.

dimnames

An optional list specifying row and column names for the output matrix.

Value

For rowCopy, a matrix with times rows and length(x) columns, where each row is x. For colCopy, a matrix with length(x) rows and times columns, where each column is x.

Details

These functions are shortcuts for building a matrix where every row (or every column) is the same vector. They are equivalent to calling matrix with appropriate byrow and dimension arguments.

See also

matrix, rbind, cbind

Examples

x <- c(3, 1, 4, 1, 5)

# stack x as rows
rowCopy(x, 4)
#>      [,1] [,2] [,3] [,4] [,5]
#> [1,]    3    1    4    1    5
#> [2,]    3    1    4    1    5
#> [3,]    3    1    4    1    5
#> [4,]    3    1    4    1    5

# stack x as columns
colCopy(x, 4)
#>      [,1] [,2] [,3] [,4]
#> [1,]    3    3    3    3
#> [2,]    1    1    1    1
#> [3,]    4    4    4    4
#> [4,]    1    1    1    1
#> [5,]    5    5    5    5

# with custom dimension names
dnames <- list(rows = c("r1", "r2", "r3"), cols = c("c1", "c2", "c3", "c4", "c5"))
rowCopy(x, 3, dnames)
#>     cols
#> rows c1 c2 c3 c4 c5
#>   r1  3  1  4  1  5
#>   r2  3  1  4  1  5
#>   r3  3  1  4  1  5