##nonhomogeneous poisson 1##
lambda<-function(t){
1+t/5}
lmax<-3
T<-10
t<-0
S<-rep(0,100)
for (i in 1:100){
u<-runif(1)
t<-t-1/lmax*log(u)
if(t<T){
u<-runif(1)
if(u<lambda(t)/lmax){
S[i]<-t 
i<-i+1
}else{}
}else{break}
}
Si<-S[S>0]
length(Si)
Si
##nonhomogeneous poisson 2##
U<-runif(10);a<-0.003;S<-rep(0,10);s<-0
 for (i in 1:10){
 s<-(s+a*U[i])/(1-U[i])
  S[i]=s
 }
round(S,4)
