fit Edward-Vilgis model

Post date: Aug 26, 2013 5:56:11 PM

load LPS4r10.TXT

data=LPS4r10;

enta_data=data(:,1);

xdata_l=exp(enta_data);

ydata_S=data(:,2);

global G0;

G0=270000;

para(1)=230000;

%Gc

para(2)=exp(2.6);

%lamda_max

parafit = lsqcurvefit(@fit_EV,para,xdata_l,ydata_S);

para=parafit;

alpha=1/parafit(2);

Gc=parafit(1);

Gs=G0-Gc;

eta=0.2;

D=lamda-1./(lamda.^2);

A=1-alpha^2*(lamda.^2+2./lamda);

B=1+eta*lamda.^2;

Ss=Gs.*D.*( (1-alpha^2)*(1+eta)./A.^2.*( (1-eta^2*lamda).*lamda.^2.*A./(B.^2.*(lamda+eta).^2)+alpha^2.*(lamda.^2./B+2./(lamda+eta) ) ) +eta*lamda./B./(lamda+eta)-alpha^2./A );

Sc=Gc.*D.*( (1-alpha^2)./(A.^2) - alpha^2./A );

S=Ss+Sc;

plot(enta,S,enta_data,ydata_S)

axis([0 6 0 2200000])

save lPSr1

function SEV=fit_EV(para,xdata_l)

alpha=1/para(2);

eta=0.2;

global G0;

Gc=para(1);

Gs=G0-Gc;

lamda=xdata_l;

D=lamda-1./(lamda.^2);

A=1-alpha^2*(lamda.^2+2./lamda);

B=1+eta*lamda.^2;

SEV=Gs.*D.*( (1-alpha^2)*(1+eta)./A.^2.*( (1-eta^2*lamda).*lamda.^2.*A./(B.^2.*(lamda+eta).^2)+alpha^2.*(lamda.^2./B+2./(lamda+eta) ) ) +eta*lamda./B./(lamda+eta)-alpha^2./A ) + Gc.*D.*( (1-alpha^2)./(A.^2) - alpha^2./A );