[prml] パターン認識と機械学習(第1章:序論)

44
パターン認識と機械学習 1序論 佐々木亮輔 1

Upload: ryosuke-sasaki

Post on 22-Jan-2018

226 views

Category:

Software


13 download

TRANSCRIPT

  • 1

    1

  • 2

  • 3

  • 1.1 1.2

    1.2.1 1.2.2 1.2.3 1.2.4 1.2.5 1.2.6

    1.3 1.4

    4

  • 1.5

    1.5.1 1.5.2 1.5.3 1.5.4 1.5.5

    1.6 1.6.1

    5

  • 1.1

    6

  • y(x,w)x = (x , ...,x )

    y(x,w) = w x

    M :

    wM

    1 nT

    j=0

    M

    jj

    7

  • wy(x,w)

    ex.

    E w = y(x ,w) t

    0

    ( )21

    n=1

    N

    ( n n)

    8

  • 9

  • w = y(x ,w) t + w

    ...1.3

    E~( )

    21

    n=1

    N

    ( n n) 2 2

    10

  • 1.2

    p(B)

    FB

    p(BF )

    11

  • p(X) = p(X,Y )

    p X,Y = p(Y X)p(X)

    Y

    ( )

    12

  • DH

    p HD =

    ( )p(D)

    p DH p(H)( )

    13

  • 1.2.1 x (x,x+ x) p(x) 0 p(x)x p(x)

    p(x (a, b)) = p(x)dx

    2

    p(x) 0

    p(x)dx = 1

    a

    b

    14

  • P (x) = p(x)dx

    x

    z

    15

  • 1.2.2

    f(x)p(x)

    E[f ] = p(x)f(x)dx

    f(x)E[f(x)]

    var[f ] = E (f(x) E[f(x)])

    [ 2]

    16

  • 1.2.3

    wD

    Dw

    17

  • 22

    1 2

    30 20

    10 20

    18

  • P H D =

    P H D 1

    P DH 1

    P (H ) 1

    P (D)

    ( 1 )P (D)

    P DH P (H )( 1) 1

    ( 1 )

    ( 1)

    1

    19

  • 11

    1

    0.5 0.75 0.600

    2

    0.5 0.5 0.400

    P (H D) = 0.6

    0.50.75+0.50.51

    0.50.75+0.50.51

    1

    20

  • 2n n+ 1

    1

    0.6 0.75 0.692

    2

    0.4 0.5 0.308

    P (H D) = 0.692

    0.60.75+0.40.51

    0.60.75+0.40.51

    1

    21

  • 1.2.4

    N (x, ) = exp (x )

    :https://ja.wikipedia.org/wiki/

    2

    (2 )2 21

    1 (221 2)

    22

    https://ja.wikipedia.org/wiki/%E6%AD%A3%E8%A6%8F%E5%88%86%E5%B8%83

  • N (x, ) > 0, N (x, )dx = 1

    E[x] = , var[x] =

    2

    2

    2

    23

  • 0

    24

  • p(x, ) = N (x , )

    2

    n=1

    N

    n2

    25

  • ln p(x, ) = (x ) ln ln(2)2221

    n=1

    N

    n2

    2N 2

    2N

    26

  • 0

    = x

    = (x )

    MLN

    1

    n=1

    N

    n

    2

    ML2

    N

    1

    n=1

    N

    n ML

    27

  • 1.2.5 = y(x,w) t

    p(tx,w,) = N ty(x,w),

    p(tx,w,) = N t y(x ,w),

    w ,

    21

    ( 1)

    n=1N ( n n 1)

    ML ML

    28

  • w

    p(w) = N (w0, I)

    : , I:

    w

    p(wx, t,,) p(tx,w,)p(w)

    1

    29

  • MAPw

    y(x ,w) t + w w2

    n=1

    N

    { n n}2 2

    30

  • 1.2.6 w

    To Be Continue;

    31

  • 1.3 1LOO: Leaveoneoutmethod

    32

  • 1.3 1

    AIC: Akaike information criterionBayesian information criterion

    w

    33

  • 1.4 DMD

    ex.

    y(x,w) = w + w x + w x x

    M

    0

    i=1

    D

    i i

    i=1

    D

    j=1

    D

    ij i j

    34

  • 35

  • 1.5 t

    36

  • 1.5.1 K

    p(true) = p(x,C )dxk=1

    K

    Rk

    k

    37

  • 1.5.2

    E(L) = L p(c x)

    L

    k

    kj k

    38

  • 1.5.3 p(x,C )

    p(C x)x

    k

    k

    39

  • 1.5.4

    http://s0sem0y.hatenablog.com/entry/2017/06/08/010513

    40

    http://s0sem0y.hatenablog.com/entry/2017/06/08/010513

  • xf(w,x)

    41

  • 42

  • GAN

    43

  • 1.6 x

    H[x] = p(x) log p(x)

    to be continue

    x

    2

    44