How to fit a logarithmic curve to my data;

Hello everyone! Please, i need your feedback! I would like to to fit a log equation to my data but i cannot find it neither in curve fitting app nor in basic fitting in plots. How can i do it? Thanks in advance!

Answer 1

[Torsten]

Use lsqcurvefit (or fminsearch if you don't have the optimization toolbox).

Best wishes

Torsten.

[Alexandra Tzilivaki]

Many thanks Torsten! I have also used fittype

myfittype=fittype('a +b*log(x)',...
'dependent', {'y'}, 'independent',{'x'},...
'coefficients' {'a,b'});
myfit=fit(x',y',myfittype);

However, MATLAB shows warning cause start point is not provided in fit. How can i put it?

Thanks again!

[Torsten]

myfit=fit(x',y',myfittype,'StartPoint',[1 1]);

Best wishes

Torsten.

[Alexandra Tzilivaki]

Thanks a Lot!

[Shivam Kumar Pandey]

how to plot this now