methods of information geometry 05

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semi slide for Shun-Ichi Amari , Hiroshi Nagaoka 'Methods of Information Geometry' section 3.4 - 3.5, about alpha-affine manifold, alpha-divergence, alpha-family

TRANSCRIPT

  • x3.4 - x3.5

    @liang4673

    2013/3/13()

    2013/3/13() 1 / 14

  • previous contents

    1 RiemannRiemann

    2 Fisher-3

    Legendre

    2013/3/13() 2 / 14

  • todays contents

    abstract

    1 - - - -

    2

    2013/3/13() 3 / 14

  • todays contents

    review

    -

    n S = fpg

    ()ij;k := E

    @i@jl +1 2

    @il@jl

    (@kl)

    < r()@i @j ; @k >= ()ij;k

    r(0) : Fisher Riemannr(1) : (exponential family)r(e)r(1) : (mixture family)r(m)

    2013/3/13() 4 / 14

  • todays contents

    review

    (S; g;r;r) X;Y; Z 2 T (S)

    Z < X;Y >=< rZX;Y > + < X;rZY >

    r r g (dual)@kgij = ki;j + kj;ir()r() Fishier

    2013/3/13() 5 / 14

  • todays contents

    alpha-ane manifold

    -:

    S = fp(xj )j 2 g Rp(xj )dx = constant

    L()(u) :=

    (2

    1u(1)=2 ( 6= 1)

    log u ( = 1)

    l()(xj ) := L()(p(xj ))

    2013/3/13() 6 / 14

  • todays contents

    alpha-ane manifold

    -:

    Fisher

    gij() =Z@il

    ()(xj ) @jl()(xj )dx

    ()ij;k =Z@i @j l

    ()(xj ) @k l()(xj )dx

    2013/3/13() 7 / 14

  • todays contents

    alpha-ane manifold

    -:

    S = fp(xj )j 2 g -[i]

    @i @j l()(xj ) = 0

    x fC;Fig

    l()(xj ) = C(x) + iFi(x)

    S

    2013/3/13() 8 / 14

  • todays contents

    alpha-ane manifold

    -:

    !?(S; g;r();r())

    i :=ZFi(x)l()(xj )dx

    [i] i

    () =

    (2

    1+

    Rp(xj )dx ( 6= 1)R

    p(xj )(log p(xj ) 1)dx ( = 1)

    2013/3/13() 9 / 14

  • todays contents

    alpha-divergence

    -:

    - D()(pjjq)8p;q 2 P;8 2 R

    D()(pjjq) := 41 2

    Z 1 2

    p+1 + 2

    q

    p(1)=2q(1+)=2dx ( 6= 1)

    D(1)(pjjq) = D(1)(qjjp) :=Z

    q p+ p log pq

    dx

    2013/3/13() 10 / 14

  • todays contents

    alpha-divergence

    -:,

    D(1)(jj) : Kullback-Leibler divergence (ex.EM-algorithm : mixture model)

    D(0)(jj) : Hellinger

    2013/3/13() 11 / 14

  • todays contents

    alpha-family

    -:

    : S = fp(xj)j 2 g (3.35)

    S := fp(xj )j 2 ; > 0g

    - : S - S = fp(xj)j 2 g

    p(xj ) =(

    nXi=0

    ci()Fi(x)

    )2=(1)

    2013/3/13() 12 / 14

  • todays contents

    alpha-family

    -:

    (1)- : (1)-(1)-1- : 1-(1)- S () M

    M S e- () M - S M ( 3.11)

    2013/3/13() 13 / 14

  • todays contents

    foliation

    : ( 3.4)

    2013/3/13() 14 / 14

    previous contentstoday's contentsabstractreviewalpha-affine manifoldalpha-divergencealpha-familyfoliation