# Example of R code for simple matrix operations
#

# Create matrices
A <- matrix(c(1,5, 2,1, 3,2), nrow=2, ncol=3)

B <- matrix(c(2, 4, -2, 0, 3, 1), nrow=3, ncol=2)

# Matrix addition (A plus transpose of B)

A + t(B)

# or so save to a matrix C
C <- A + t(B)

# Matrix multiplication

AB <- A %*% B
BA <- B %*% A


# Note that the following does element by element multiplication
AtB <- A * t(B)

# Determinant of a matrix
A <- matrix(c(4, 2, 1, 3,
              3, 5, 3, 2,
              2, 1, 2, 1,
              1, 0, 1, 4),
              nrow=4, ncol=4)
det <- det(A)

# inverse of a matrix

invA <- solve(A)

# Check
AinvA <- A %*% invA
invAA <- invA %*% A