R in Action, Third Edition

Appendix D. Matrix algebra in R

Many of the functions described in this book operate on matrices. The manipulation of matrices is built deeply into the R language. Table D.1 describes operators and functions that are particularly important for solving linear algebra problems. In the table, A and B are matrices, x and b are vectors, and k is a scalar.

Table D.1 Functions and operators for matrix algebra

Operator or function	Description
+ - * / ^	Element-wise addition, subtraction, multiplication, division, and exponentiation, respectively
A %*% B	Matrix multiplication
A %o% B	Outer product: AB'
cbind(A, B, ...)	Combines matrices or vectors horizontally. Returns a matrix.
chol(A)	Cholesky factorization of A