Transposing and Reshaping Matrices
Use t(), dim(), and reshape operations on matrices.
Transposing a Matrix with t()
t(m) transposes a matrix — it flips rows and columns so that row i becomes column i in the result. The dimensions swap: a 3x4 matrix becomes a 4x3 matrix after transposition.
m <- matrix(1:6, nrow = 2, ncol = 3)
cat('Original (2x3):
'); print(m)
cat('Transposed (3x2):
'); print(t(m))
cat('Original dim:', dim(m), '-> Transposed dim:', dim(t(m)), '
')Transpose with Named Dimensions
When a matrix has row and column names, t() correctly swaps the names: row names become column names and vice versa. This keeps your data labelled after transposition.
scores <- matrix(
c(88,92,75, 79,85,90),
nrow = 2, byrow = TRUE,
dimnames = list(c('Alice', 'Bob'), c('Math', 'Sci', 'Eng'))
)
cat('Original (students x subjects):
'); print(scores)
cat('Transposed (subjects x students):
'); print(t(scores))All lessons in this course
- Creating Matrices with matrix()
- Matrix Indexing and Subsetting
- Matrix Arithmetic and Operations
- Transposing and Reshaping Matrices