v=rand(1,4)

v =

    0.8147    0.9058    0.1270    0.9134

v=v/sum(v)

v =

    0.2951    0.3281    0.0460    0.3308

cumsum(v)

ans =

    0.2951    0.6232    0.6692    1.0000

v(1)+v(2)

ans =

    0.6232

sum(v(1:3))

ans =

    0.6692

sum(v)

ans =

    1.0000

cumsum(v)

ans =

    0.2951    0.6232    0.6692    1.0000

rand

ans =

    0.6324

u=ans

u =

    0.6324

find(u<cumsum(v))

ans =

     3     4

find(u<cumsum(v),1)

ans =

     3

find(rand<cumsum(v),1)

ans =

     1

find(rand<cumsum(v),1)

ans =

     1

find(rand<cumsum(v),1)

ans =

     2

find(rand<cumsum(v),1)

ans =

     4

find(rand<cumsum(v),1)

ans =

     4

find(rand<cumsum(v),1)

ans =

     1

edit
randdisc([1/2,1/2])

ans =

     2

for i = 1:100
u(i)=randdisc([1/2,1/2]);
end
u

u =

  Columns 1 through 8

     2     1     2     1     1     2     2     2

  Columns 9 through 16

     2     1     2     2     2     2     2     1

  Columns 17 through 24

     2     1     2     1     1     1     1     2

  Columns 25 through 32

     2     1     2     1     1     1     2     2

  Columns 33 through 40

     1     1     1     2     2     2     1     2

  Columns 41 through 48

     2     1     1     1     2     1     2     1

  Columns 49 through 56

     2     1     2     2     2     2     2     1

  Columns 57 through 64

     1     1     2     1     2     1     2     1

  Columns 65 through 72

     1     1     2     1     1     2     2     2

  Columns 73 through 80

     2     1     2     2     1     2     1     1

  Columns 81 through 88

     2     2     2     1     2     1     1     1

  Columns 89 through 96

     1     2     1     2     1     2     1     2

  Columns 97 through 100

     2     2     1     1

find(u==1)

ans =

  Columns 1 through 8

     2     4     5    10    16    18    20    21

  Columns 9 through 16

    22    23    26    28    29    30    33    34

  Columns 17 through 24

    35    39    42    43    44    46    48    50

  Columns 25 through 32

    56    57    58    60    62    64    65    66

  Columns 33 through 40

    68    69    74    77    79    80    84    86

  Columns 41 through 48

    87    88    89    91    93    95    99   100

length(find(u==1))

ans =

    48

edit
P=randstoc(5);
simula(P,10)

ans =

     1

simula(P,10)

ans =

     2

simula(P,10,4)

ans =

     4

testsimula
testsimula
testsimula
counter(2)

n =

     2

counter(2)

n =

     2


i =

     1


i =

     0

x=linspace(pi/2,2*pi);
H=x.^2*sin(x);
??? Error using ==> mtimes
Inner matrix dimensions must agree.

H=x.^2.*sin(x);
plot(x,H)
H=x.^2.*sin(3*x);
plot(x,H)
sa(100)

counterstati =

    35


ans =

  -33.3802

sa(100)

counterstati =

    24


ans =

  -31.6899

sa(100)

counterstati =

    96


ans =

  -33.3802

sa(100)

counterstati =

    51


ans =

  -32.8900

sa(100)

counterstati =

    52


ans =

  -31.6899

sa(100)

counterstati =

    74


ans =

  -33.3802

sa(100)

counterstati =

   118


ans =

  -33.3802

sa(100)

counterstati =

    46


ans =

  -31.6899

sa(100)

counterstati =

   126


ans =

  -32.8900

sa(100)

counterstati =

   149


ans =

  -33.1728

sa(100)

counterstati =

   104


ans =

  -33.3802

sa(100)

counterstati =

    82


ans =

  -33.3802

sa(100)

counterstati =

    40


ans =

  -33.1728

sa(100)

counterstati =

    29


ans =

  -32.2947

sa(100)

counterstati =

    59


ans =

  -32.2947

sa(100)

counterstati =

    23


ans =

  -30.7856

sa(100)

counterstati =

    32


ans =

  -32.8900

sa(100)

counterstati =

    22


ans =

  -23.9314

sa(100)

counterstati =

    28


ans =

  -30.7856

sa(200)

counterstati =

    56


ans =

  -32.3660

sa(200)

counterstati =

    61


ans =

  -32.3660

sa(200)

counterstati =

    30


ans =

  -23.8416

sa(200)

counterstati =

    40


ans =

  -32.8511

sa(200)

counterstati =

    27


ans =

  -32.3660

sa(200)

counterstati =

    24


ans =

  -32.8511

sa(200)

counterstati =

    64


ans =

  -33.3724

sa(200)

counterstati =

    47


ans =

  -33.1992

sa(200)

counterstati =

    23


ans =

  -33.3723

sa(400)

counterstati =

    20


ans =

  -30.5072

sa(400)

counterstati =

    39


ans =

  -31.5951

sa(400)

counterstati =

    24


ans =

  -28.9427

sa(400)

counterstati =

    38


ans =

  -32.6647

sa(400)

counterstati =

    80


ans =

  -33.3936

sa(400)

counterstati =

    33


ans =

  -33.2989

sa(400)

counterstati =

    20


ans =

  -33.1866

sa(400)

counterstati =

    37


ans =

  -28.3552

sa(400)

counterstati =

    34


ans =

  -32.8312

sa(1000)

counterstati =

    32


ans =

  -33.2239

sa(2000)

counterstati =

    32


ans =

  -32.7220

sa(10000)

counterstati =

    38


ans =

  -32.8023

sa(10000)

counterstati =

    39


ans =

  -33.3588

1/(1.01)^20

ans =

    0.8195

sa(2000)

counterstati =

    40


ans =

  -31.9983

sa(2000)

counterstati =

    49


ans =

  -33.2493

sa(2000)

counterstati =

    29


ans =

  -33.3938

sa(2000)

counterstati =

    64


ans =

  -33.2507

sa(2000)

counterstati =

    39


ans =

  -33.3079

sa(2000)

counterstati =

    42


ans =

  -33.3858

sa(2000)

counterstati =

    23


ans =

  -32.7347

sa(2000)

counterstati =

    34


ans =

  -33.3902

sa(2000)

counterstati =

    66


ans =

  -30.8765

sa(2000)

counterstati =

    36


ans =

  -32.8152

sa(2000)

counterstati =

    32


ans =

  -32.9418

sa(2000)

counterstati =

    32


ans =

  -31.4164

diary off