Like matrix, this function creates a matrix from the given set of values. However, these values can also be represented by a character string, or a list of vectors. Initially inspired by NumPy's matrix function.
Usage
mat(x, ...)
# Default S3 method
mat(x, ...)
# S3 method for class 'character'
mat(x, rows = TRUE, sep = ",", eval = FALSE, ...)
# S3 method for class 'list'
mat(x, rows = TRUE, ...)Arguments
- x
A data vector, character string, or a list.
- ...
Additional optional arguments to be passed on to matrix.
- rows
Logical. If
TRUE(the default) the matrix is filled by rows, otherwise the matrix is filled by columns.- sep
Separator string. Values within each row/column of x are separated by this string. Default is
",".- eval
Logical indicating whether or not the character string contains R expressions that need to be evaluated. Default is
FALSE. See examples below for usage.
Value
A matrix.
Examples
# Creating a matrix from a character string
mat("1, 2, 3, 4; 5, 6, 7, 8") # ";" separates rows
#> [,1] [,2] [,3] [,4]
#> [1,] 1 2 3 4
#> [2,] 5 6 7 8
mat("1, 2, 3, 4; 5, 6, 7, 8", rows = FALSE) # ";" separates columns
#> [,1] [,2]
#> [1,] 1 5
#> [2,] 2 6
#> [3,] 3 7
#> [4,] 4 8
mat("1 2 3 4; 5 6 7 8", sep = "") # use spaces instead of commas
#> [,1] [,2] [,3] [,4]
#> [1,] 1 2 3 4
#> [2,] 5 6 7 8
mat(c(1, 2, 3, 4, 5, 6, 7, 8), nrow = 2, byrow = TRUE) # works like matrix too
#> [,1] [,2] [,3] [,4]
#> [1,] 1 2 3 4
#> [2,] 5 6 7 8
# Character strings containing R expressions
mat("rnorm(3); rnorm(3)")
#> [,1]
#> [1,] "rnorm(3)"
#> [2,] "rnorm(3)"
mat("rnorm(3); rnorm(3)", eval = TRUE)
#> [,1] [,2] [,3]
#> [1,] 1.0673079 0.07003485 -0.6391233
#> [2,] -0.0499649 -0.25148344 0.4447971
mat("1, 2, 3; 4, 5, pi")
#> [,1] [,2] [,3]
#> [1,] "1" "2" "3"
#> [2,] "4" "5" "pi"
mat("1, 2, 3; 4, 5, pi", eval = TRUE)
#> [,1] [,2] [,3]
#> [1,] 1 2 3.000000
#> [2,] 4 5 3.141593
mat("-1, -.1; -0.1, -1.0")
#> [,1] [,2]
#> [1,] -1.0 -0.1
#> [2,] -0.1 -1.0
# Creating a matrix from a list
z1 <- list(1:5, 6:10)
z2 <- list(a = 1:5, b = 6:10)
mat(z1)
#> [,1] [,2] [,3] [,4] [,5]
#> [1,] 1 2 3 4 5
#> [2,] 6 7 8 9 10
mat(z2) # preserves names as row names
#> [,1] [,2] [,3] [,4] [,5]
#> a 1 2 3 4 5
#> b 6 7 8 9 10
mat(z2, rows = FALSE) # preserves names as column names
#> a b
#> [1,] 1 6
#> [2,] 2 7
#> [3,] 3 8
#> [4,] 4 9
#> [5,] 5 10