MATLAB: How to make matrix dimensions to agree

matrix dimensions

Hi all, I get an error message:

Matrix dimensions must agree.
Error in lsqcurvefit/objective (line 279)
         F = F - YDATA;
Error in snls (line 333)
            newfvec = feval(funfcn{3},xcurr,varargin{:});
Error in lsqncommon (line 167)
            snls(funfcn,xC,lb,ub,flags.verbosity,options,defaultopt,initVals.F,initVals.J,caller, ...
Error in lsqcurvefit (line 271)
    lsqncommon(funfcn,xCurrent,lb,ub,options,defaultopt,allDefaultOpts,caller,...
Error in CurveFitting (line 135)
[theta,Rsdnrm,Rsd,ExFlg,OptmInfo,Lmda,Jmat]=lsqcurvefit(@kinetics,theta0,t,c);

when I run the attached code. What could be the cause of the disagreement?

Kind Regards Dursman

Best Answer

That means F =F-YDATA must be in the same dimension.

Please ensure that F and TDATA must be same before doing subtraction operation.

I have noticed in your code dcdt(2), dcdt(3),...what do these mean, are those scalar or vector variables?

Why you mixed up the function descriptions with other body code?

Related Solutions

MATLAB: How to fit the data by using lsqcurvefit

I didn't exactly understand how you went from your function to the code, so I re-implemented it. Apparently there is a functional difference, because this code does run correctly. One of the changes I made is calculating the sum as a stand-alone array. This does use implicit expansion, so if you're using R2016a or earlier you need to expand the arrays yourself first.

xdata=[0;86400;259200000;604800000;12096000000.0000;24192000000.0000];
ydata=[1.06180000000000;0.498230000000000;0.270470000000000;0.225110000000000;0.229290000000000;0.251620000000000];
x0=[1*10^-10,3];
x = lsqcurvefit(@sorptio,x0,xdata,ydata);
function ydata=sorptio(x,xdata)
D=x(1);
h=x(2);
t=xdata(:);%force nx1 size
n=0:1000;
S=(2*n+1).^(-2) .* exp( (-(2*n+1).^2 * pi^2 * D .*t)/(h^2) );
S=sum(S,2);
ydata=1-S*8/(pi^2);
ydata=reshape(ydata,size(xdata));%return to original size
end

MATLAB: How to fix Error using trustnleqn (line 28) Objective function is returning undefined values at initial point. FSOLVE cannot continue.

Only you know what your function is supposed to return, but I assume it is not this:

    >> fun_RMPL(x0_RMPL)
    ans =
       NaN   NaN

You must make it so that fun_RMPL returns a finite value.

Best Answer

Related Solutions

MATLAB: How to fit the data by using lsqcurvefit

MATLAB: How to fix Error using trustnleqn (line 28) Objective function is returning undefined values at initial point. FSOLVE cannot continue.

Related Question