169 Appendix B: R commands for matrices (continued)

$>$ cbind(A,B) [forms matrix $[A\mathit{\hspace{1em}}B]$ with $A$ beside $B$]

$>$ rbind(A,B) [forms matrix $[\left(\begin{array}{c}\hfill A\hfill \\ \hfill B\hfill \end{array}\right)]$ with $A$ on top of $B$]

$>$A% *%B [forms the matrix product $AB$]

$>$A*X [multiplies matrices $A$ and $X$, entry by entry]

$>$solve(A) [computes the inverse matrix of $A$]

$>$det(A) [computes the determinant of $A$]

$>$diag(A) [lists the entries of $A$ on the leading diagonal]

$>$sum(diag(A)) [computes the trace of $A$]

$>$eigen(A) [computes the eigenvalues and eigenvectors of $A$]

$>$exp(A) [computes the matrix formed by exp of each entry of $A$]

$>$library(expm) [invokes the library $expm$ for matrix exponential]

$>$expm(A) [computes the matrix exponential $\exp (A)$]