Check if two matrices are compatible for multiplication or have the same dimensions

check_matrices_compatible() and check_is_matrices_compatible() validate if two matrices are compatible either for matrix multiplication or have the same dimensions. check_matrices_compatible() raises an error if the matrices do not satisfy the compatibility conditions, while check_is_matrices_compatible() returns TRUE if the matrices are compatible, and FALSE otherwise.

Usage

check_matrices_compatible(
  a,
  b,
  is_multiplication = FALSE,
  apar_name = "a",
  bpar_name = "b"
)

check_is_matrices_compatible(a, b, is_multiplication = FALSE)

Arguments

a

The first matrix to check.

b

The second matrix to check.

is_multiplication

Logical indicating whether to check for compatibility for matrix multiplication. Default is FALSE).

apar_name

A name for the parameter a to display in error messages.

bpar_name

A name for the parameter b to display in error messages.

Value

• check_matrices_compatible(): Returns a list containing the input matrices a and b if they are compatible, or raises an error if the matrices do not meet the compatibility conditions.

• check_is_matrices_compatible(): Logical value, TRUE if the matrices are compatible, FALSE otherwise.

Examples

# Examples for check_matrices_compatible()
# ----------------------------------------

A <- matrix(1:6, nrow = 2)
B <- matrix(7:12, nrow = 3)
check_matrices_compatible(A, B, is_multiplication = TRUE)
#> $a
#>      [,1] [,2] [,3]
#> [1,]    1    3    5
#> [2,]    2    4    6
#> 
#> $b
#>      [,1] [,2]
#> [1,]    7   10
#> [2,]    8   11
#> [3,]    9   12
#> 

try(check_matrices_compatible(A, B))
#> Error in check_matrices_compatible(A, B) : 
#>   Matrix 'a' and 'b' must have the same dimensions but got 2 by 3 and 3 by 2 matrices respectively

C <- matrix(1:4, nrow = 2)
D <- matrix(5:8, nrow = 2)
check_matrices_compatible(C, D)
#> $a
#>      [,1] [,2]
#> [1,]    1    3
#> [2,]    2    4
#> 
#> $b
#>      [,1] [,2]
#> [1,]    5    7
#> [2,]    6    8
#> 

try(check_matrices_compatible(C, D, is_multiplication = TRUE))
#> $a
#>      [,1] [,2]
#> [1,]    1    3
#> [2,]    2    4
#> 
#> $b
#>      [,1] [,2]
#> [1,]    5    7
#> [2,]    6    8
#> 

try(check_matrices_compatible(A, "not a matrix"))
#> Error in check_matrix(mat = b, par_name = bpar_name) : 
#>   Expected 'b' to be a matrix but got character

# Examples for check_is_matrices_compatible()
# -------------------------------------------

check_is_matrices_compatible(A, B, is_multiplication = TRUE)
#> [1] TRUE

check_is_matrices_compatible(C, D)
#> [1] TRUE

check_is_matrices_compatible(C, D, is_multiplication = TRUE)
#> [1] TRUE

check_is_matrices_compatible(A, "not a matrix")
#> [1] FALSE