octave:2> v=rand(1,5)
v =

   0.47487   0.77408   0.15505   0.94272   0.84118

octave:3> v=v/sum(v)
v =

   0.148961   0.242817   0.048638   0.295719   0.263866

octave:4> rand<cumsum(v)
ans =

   0   0   0   1   1

octave:5> u=rand
u =  0.71140
octave:6> cumsum(v)
ans =

   0.14896   0.39178   0.44042   0.73613   1.00000

octave:7> u<cumsum(v)
ans =

   0   0   0   1   1

octave:8> u=rand
u =  0.60588
octave:9> u=rand
u =  0.34630
octave:10> u<cumsum(v)
ans =

   0   1   1   1   1

octave:11> find(u<cumsum(v))
ans =

   2   3   4   5

octave:12> min(find(u<cumsum(v)))
ans =  2
octave:13> testsimula
octave:14> testsimula
octave:15> quit