168 Appendix B: R commands for matrices

Beware: $R$ makes a meal of complex numbers, and is not a symbolic manipulation package.

$>$x-3 [this assigns value $x=3$]

$>$t-2 [this assigns value $t=2$]

$>$x*t [multiply $x$ and $t$]

$>$x+t [add $x$ and $t$]

$>$x/t [divide $x$ by $t$]

$>$x$\widehat{}$(-1.5) [raises $x$ to the power $-1.5$]

$>$2*((x+t)$\widehat{}$3) [computes $2{(x+t)}^3$]

$>$a-c(5,9,7,-2) [creates vector $a=(5,9,7,-2)$]

$>$A-array(a, dim=c(2,2)) [fills up a $2\times 2$ matrix, column by column, from vector a]

$>$b-c(1,4,2,5,3,6) [creates vector $b=(1,4,2,5,3,6)$]

$>$B-array(b, dim=c(2,3)) [fills up a $2\times 3$ matrix, column by column, from vector b]

$>$t(B) [forms the transpose of the matrix $B$]