2.1 Constructing a complicated matrix

In some circumstances, we might need to construct a matrix with a particular pattern. For instance, suppose we want to construct a matrix of the form

First we can create a matrix of the correct dimension

M <- matrix(0,10,10)

One way to proceed is to use a for loop

for (i in 1:10) {

M[i,i]<-1

if (i>1) M[i,i-1]<--1

if (i<10) M[i,i+1]<--1

}