I tried to use fminsearch to solve an equation with three unknown parameters but there is an error:
fi1=[0.6787*1.0e-5 0.4520*1.0e-5 0.3519*1.0e-5 0.2655*1.0e-5 0.2317*1.0e-5]; Hw=[0.3974 0.3186 0.2612 0.1816 0.1284];
The function is: error=fi1-(A+(B*(Hw^n))); I would like to compute A,B and n. Initial guess; A=0.005, B=0.4, n=2
The codes are but error say define B?
error=inline(fi1-(A+(B.*(Hw.^n)))); xo=[0.005 0.4 2]; [x,fval,exitflag,output] = fminsearch(error,x0)

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Torsten
Torsten am 31 Mär. 2015

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error=@(x)(fi1-(x(1)+x(2)*Hw.^x(3)))*(fi1-(x(1)+x(2)*Hw.^x(3)))';
x0=[0.005 0.4 2];
[x,fval,exitflag,output] = fminsearch(error,x0);
Best wishes
Torsten.

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Parham Babakhani Dehkordi
Parham Babakhani Dehkordi am 31 Mär. 2015
Thank you Torsten, I copied your codes into my script, again there is an error as follows:
Attempt to execute SCRIPT fminsearch as a function: C:\Users\nima\Desktop\interfacial tensions\fminsearch.m
Error in interfacial_friction_factors (line 42) [x,fval,exitflag,output] = fminsearch(error,x0);

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