# NOT RUN {
## Rosenbrock's banana function
n=3; p=100
fr = function(x)
{
f=1.0
for(i in 2:n) {
f=f+p*(x[i]-x[i-1]**2)**2+(1.0-x[i])**2
}
f
}
grr = function(x)
{
g = double(n)
g[1]=-4.0*p*(x[2]-x[1]**2)*x[1]
if(n>2) {
for(i in 2:(n-1)) {
g[i]=2.0*p*(x[i]-x[i-1]**2)-4.0*p*(x[i+1]-x[i]**2)*x[i]-2.0*(1.0-x[i])
}
}
g[n]=2.0*p*(x[n]-x[n-1]**2)-2.0*(1.0-x[n])
g
}
x = c(1.02,1.02,1.02)
op1 <- qnbd(x, fr, grr)
# }
Run the code above in your browser using DataLab