A = matrix(1:10, 5, 2)
B = matrix(letters[1:10], 5, 2)
C = 1:10
is_matrix(A) # TRUE
is_matrix(C) # FALSE
is_not_matrix(C) # TRUE
is_numeric_matrix(A) # TRUE
is_numeric_matrix(B) # FALSE
is_string_matrix(A) # FALSE
is_string_matrix(B) # TRUE
Run the code above in your browser using DataLab