```
Rectpsa = function(A,grid){
m = nrow(A)
n = ncol(A)
if (m >=2*n){
QR <- qr(A[n+1:m,])
Q = qr.Q(QR)
R = qr.R(QR)}
I = diag(nrow(n))
else ...
}
A = matrix(c(0, 2, 2,4,
0, 1, 2,4,
1, 0, 1,4,
0, 2, 2,4,
0, 1, 2,4,
1, 0, 1,4,
0, 1, 2,4,
1, 0, 1,4),8,4,byrow =TRUE)
A
z = seq(1,10,0.001)*1i
```

But my knowledge in R comes only with this.Any help?