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graphics - How to compute the Multifractal Spectrum of a Financial Series with WTMM


I would like to know if someone knows how to compute the Multifractal Spectrum of a Financial Time Series (Currency) througth the Wavelet Transformation Modulus Maxima (WTMM).


I would highly appreciate any hint in order to calculate Dq, Tau(q), alpha, f(alpha).


I am pasting here the code I am using to get the Multifractal Spectrum (Ref: Gerd Baumann - Mathematica for Theoretical Physics (Mathematica 6.0), Springer Second Edition (2005), page 892) Comments: The following code helps to get the MultiFractal Spectrum, with Mathematica 6.0. I have updated the function ListPlot to ListLinePlot and PlotJoined to Joined as suggested in the Help of Mathematica 8.0.


The code seems to work when the input are the probabilities pi ={p1,p2,....pn} and when the values of each subset of the probability space one is seeking to characterize.


The code doesn't work 100% and I still don't know why (I am new to Mathematica).


The thing is, that the package provided by Mr. Baumann works when you give the input of the probabilities - yet I need that such process should be automated by the WTMM so I can see (analyze) the Whole Multifractal Spectrum.


----------------- ## ----------------------------



BeginPackage["MultiFractal`"];
Clear[Dq, Tau, Alpha, MultiFractal];
MultiFractal::usage = "MultiFractal[p_List,r_List] calculates the 
        multifractal spectrum D_q for a model based on the probabilities
        p and the scaling factors r. This function plots five functions
        Tau(q), D_q(q), Alpha(q), f(q) and f(Alpha).";
Begin["Private`"];

(*---calculate the multifractal dimensions---*)
Dq[p_List, r_List] := Block[{l1, l2, listrg = {}},

   (*---length of the lists---*)
   l1 = Length[p]; l2 = Length[r];
   If[l1 == l2,
    (*---variation of q and determination of D_q---*)
    Do[gl1 = Sum[p[[j]]^q r[[j]]^((q - 1) Dfractal), {j, 1, l1}] - 1;
     result = FindRoot[gl1 == 0, {Dfractal, -3, 3}];
     result = -Dfractal /. result;
     (*---collect the result in a list----*)
     AppendTo[listrg, {q, result}], {q, -10, 10, .101}]
    ,

    Print[" "];
    Print["  Lengths of lists are different!"];
    listrg = {}];
   listrg];

(*----calculate Tau---*)
Tau[result_list] := Block[{l1, listtau = {}},
   (*----lengths of the lists---*)
   l1 = Length[result];
   (*---calcultate Tau---*)

   Do[AppendTo[
     listtau, {result[[k, 1]], 
      result[[k, 2]] (1 - result[[k, 1]])}], {k, 1, l1}];
   listtau];

(*---Legendre transform---*)
Alpha[result_List] := 
  Block[{l1, dq, listalpha = {}, listf = {}, listleg = {}, mlist = {},
     pl1, pl2},
   (*---lengths of the lists---*)

   l1 = Length[result];
   (*---determine the differential dq---*)
   dq = (result[[2, 1]] - result[[1, 1]]) 2;
   (*---calculate Alpha by numerical differentiation---*)
   Do[AppendTo[
     listalpha, {result[[k, 
        1]], (result[[k + 1, 2]] - result[[k - 1, 2]])/dq}], {k, 2, 
     l1 - 1}];
   l1 = Length[listalpha];
   (*---calculate f and collect the result in a list---*)

   Do[AppendTo[
     listf, {result[[k, 
        1]], -(result[[k, 1]] listalpha[[k, 2]] - result[[k, 2]])}];
    listalpha[[k, 2]] = -listalpha[[k, 2]], {k, 1, 12}];
   (*---list of the Legendre transforms---*)
   Do[AppendTo[listleg, {listalpha[[k, 2]], listf[[k, 2]]}]; 
    AppendTo[mlist, listf[[k, 2]]], {k, 1, l2}];
   (*---plot f and alpha versus q---*)
   pl1 = ListLinePlot[listalpha, Joined -> {True, False}, 
     AxesLabel -> {"q", "\[Alpha]"}, Prolog -> Thickness[0.001]];

   pl2 = ListLinePlot[listf, Joined -> {True, False}, 
     AxesLabel -> {"q", "f"}, Prolog -> Thickness[0.001]];
   Show[{pl1, pl2}, AxesLabel -> {"q", "\[Alpha],f"}];
   (*---plot the Legendre transform f versus alpha---*)
   ListLinePlot[listleg, AxesLabel -> {"\[Alpha]", "f"}];
   (*---print the maximum of f=D_ 0---*)
   maxi = Max[mlist];
   Print[" "];
   Print["   D_0 = ", maxi]];


(*---calcultate the multifractal properties---*)
MultiFractal[p_List, r_List] := Block[{listDq, listTau},
   (*---determine D_q---*)
   listDq = Dq[p, r];
   ListLinePlot[listDq, Joined -> {True, False}, 
      AxesLabel -> {"q", "Dq"}, Prolog -> Thickness[0.001]]
     (*---calculate Tau---*)
      listTau = Tau[listDq];
   ListLinePlot[listTau, Joined -> {True, False}, 
     AxesLabel -> {"q", "\[Tau]"}, Prolog -> Thickness[0.001]]

    (*---determine the Hoelder exponent---*) 
    Alpha[listTau]];

End[];

EndPackage[];

Answer



The code (Importation de la série)


ClearAll["Global`*"]
d = Import[SystemDialogInput["FileOpen"]];

ima = Flatten[d];
ima = ima + 0.000001;
n1 = Length[d];
n2 = Log[2, Length[ima]];
ny = Table[2^i, {i, 3, n2}];

(*Calcul des valeurs Dq pour chaque sous série*)

f[n_] := Module[{xx = ima, d2, stot, freqpuis, somfreqpuis, pq},
  d2 = Partition[xx, n];

  fmaxmin[x_List] := Mean[x];
  stot = Map[fmaxmin, d2] // N;
  stot = stot/Total[Flatten[stot]];
  freqpuis = Table[stot^j, {j, -7, 7, 0.5}];
  somfreqpuis = Total[Transpose[freqpuis]];
  pq = Log[2, somfreqpuis]
  ]

logmuql = Flatten[Table[f[i], {i, ny}]] // N;
logmuqlt = Partition[logmuql, 29];

pqpart = logmuqlt;
logtaille = Log[2, ny] // N;

f2[nn_] := 
 Module[{a = logtaille, b = logmuqlt, essai, line, linen, fa1},
  essai = Partition[Riffle[logtaille, logmuqlt[[All, nn]]], 2];
  line = LinearModelFit[essai, x, x];
  linen = Normal[line];
  fa1 = linen[[2, 1]] // N
  ]


Dq = Table[f2[i], {i, 1, 29}];
qq = Table[i, {i, -7, 7, 0.5}];
q = 1/(qq - 1.000001);
Dqq = q*Dq;
kq = 2 - Dqq;
cq = kq*q;
qmoin = qq - 1;
rq = qmoin*Dq;
ecartDq = Dqq[[1]] - Dqq[[29]] // N;

Print["ecart Dq = ", ecartDq]
ListPlot[{pqpart[[All, 1]], pqpart[[All, 5]], pqpart[[All, 10]], 
   pqpart[[All, 15]], pqpart[[All, 20]], pqpart[[All, 29]]}, 
 ImageSize -> {300, 200}, Joined -> True, 
 AxesLabel -> {"log_tailleboite", "SomPiQ"}, PlotRange -> All, 
 PlotStyle -> PointSize[Medium]]

dqrel = Dqq - 1;
d3 = Riffle[qq, Dqq];
d6 = Partition[d3, 2];

d6 = Drop[d6, {17}];

ListPlot[{d6}, 
  ImageSize -> {300, 200}, Joined -> True, 
  AxesLabel -> {"q", "Dq"}, PlotRange -> All, PlotStyle -> {Black}]

d3 = Riffle[qq, kq];
d6 = Partition[d3, 2];
d6 = Drop[d6, {17}];


ListPlot[{d6}, ImageSize -> {300, 200}, Joined -> True, 
 AxesLabel -> {"q", "Kq"}, PlotRange -> All, PlotStyle -> {Black}]

d3 = Riffle[qq, cq];
d6 = Partition[d3, 2];
d6 = Drop[d6, {17}];
ListPlot[{d6}, 
  ImageSize -> {300, 200}, Joined -> True, 
   AxesLabel -> {"q", "Cq"}, PlotRange -> All, PlotStyle -> {Black}]


d3 = Riffle[qmoin, rq];
d6 = Partition[d3, 2];
d6 = Drop[d6, {17}];
ListPlot[{d6}, 
 ImageSize -> {300, 200}, Joined -> True, 
 AxesLabel -> {"q", "Tauq"}, PlotRange -> All, PlotStyle -> {Black}]

d3 = Riffle[qq, dqrel];
d6 = Partition[d3, 2];
d6 = Drop[d6, {17}];

ListPlot[{d6}, 
  ImageSize -> {300, 200}, Joined -> True, 
  AxesLabel -> {"q", "Dq_Relatif"}, PlotRange -> All, 
  PlotStyle -> {Black}]

fo[n_] := 
  Module[{xx = ima, d2, stot, tfreqpuis, freqpuis, logfreqpuis, 
    produitfreq, somfproduit4},
  d2 = Partition[xx, n];
  fmaxmin[x_List] := Mean[x];

  stot = Map[fmaxmin, d2] // N;
  freqpuis = Table[stot^j, {j, -7, 7, 0.5}];
  tfreqpuis = Total[Transpose[freqpuis]];
  freqpuis = freqpuis/tfreqpuis;
  logfreqpuis = Log[10, freqpuis];
  produitfreq = freqpuis*logfreqpuis;
  somfproduit4 = Map[Total, produitfreq] // N
  ]

totlogmuql = Flatten[Table[fo[i], {i, ny}]];

logmuqlt = Partition[totlogmuql, 29];
pqpart = logmuqlt;
logtaille = Log[10, ny] // N;

fo2[nn_] := 
 Module[{a = logtaille, b = logmuqlt, essai, line, linen, fa1},
  essai = Partition[Riffle[logtaille, logmuqlt[[All, nn]]], 2];
  line = LinearModelFit[essai, x, x];
  linen = Normal[line];
  fa1 = ToExpression[linen[[2, 1]]] // N

  ]

fqr = Table[fo2[i], {i, 1, 29}];
qq = Table[i, {i, -7, 7, 0.5}];
fq2 = Riffle[qq, fqr];
fq2 = Partition[fq2, 2];

ListPlot[{fq2}, 
  ImageSize -> {300, 200}, Joined -> True, 
  AxesLabel -> {"q", "f(alpha)q"}, PlotRange -> All, 

  PlotStyle -> {Black}]
ecartFq = fqr[[29]] - fqr[[1]] // N;
Print["ecart Fq = ", ecartFq]

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