nf_cpm.m

来自「计算动力学系统的分岔图」· M 代码 · 共 21 行

function coef= nf_CPm(mapsf,mapsJ,mapsH,mapsDer3,A,vext,wext,nphase,x0,p,n)
%
% coef= nf_CPm(mapsf,mapsJ,mapsH,mapsDer3,A,vext,wext,nphase,x0,p,n) 
% compute cusp normal form coefficient.
%
global cds T1global T2global T3global
  hessIncrement =(cds.options.Increment)^(3.0/4.0);
  ten3Increment =(cds.options.Increment)^(3.0/5.0);
  if (cds.options.SymDerivative >= 3)
    T1global=tens1(mapsf,mapsJ,x0,p,n);
    T2global=tens2(mapsf,mapsH,x0,p,n);
    T3global=tens3(mapsf,mapsDer3,x0,p,n);
  end
  h2 = multilinear2(mapsf,vext,vext,x0,p,n,hessIncrement);        		%B(q,q)
  h2 = [A-eye(nphase) vext ; wext' 0]\[(wext'*h2)*vext-h2; 0];	    		%h2 = (A-I)^{INV}(-B(q,q))
  h2 = h2(1:nphase);
  RHS3 =  multilinear3(mapsf,vext,vext,vext,x0,p,n,ten3Increment);  		%   C(q,q,q)
  RHS3 = RHS3 + 3.0*multilinear2(mapsf,vext,h2,x0,p,n,hessIncrement);		% +3B(q,h2)  
  coef = wext'*(RHS3)/6.0;
clear T1global T2global T3global;