How is it possible that a fitobject can used as an input for the plot function?

How is it possible that a fitobject can used as an input for the plot function?

Answer 1

[Titus Edelhofer]

That's because the fit object has a method called plot:

x = fit([1 2 3]', [4 5 6.5]', 'linear')
x = 
   Linear interpolant:
     x(x) = piecewise polynomial computed from p
   Coefficients:
     p = coefficient structure

You can use which to find out:

which plot(x)
C:\MATLAB\R2015b\toolbox\curvefit\curvefit\@cfit\plot.m  % cfit method

Other objects define a plot method as well:

 which -all plot
built-in (C:\MATLAB\R2015b\toolbox\matlab\graph2d\plot)
C:\MATLAB\R2015b\toolbox\curvefit\curvefit\@cfit\plot.m         % cfit method
C:\MATLAB\R2015b\toolbox\matlab\graphfun\@graph\plot.m          % graph method
C:\MATLAB\R2015b\toolbox\matlab\graphfun\@digraph\plot.m        % digraph method
C:\MATLAB\R2015b\toolbox\matlab\polyfun\@alphaShape\plot.m      % alphaShape method
C:\MATLAB\R2015b\toolbox\matlab\timefun\@duration\plot.m        % duration method
C:\MATLAB\R2015b\toolbox\matlab\timefun\@datetime\plot.m        % datetime method
C:\MATLAB\R2015b\toolbox\curvefit\curvefit\@sfit\plot.m         % sfit method
C:\MATLAB\R2015b\toolbox\finance\ftseries\@fints\plot.m         % fints method
C:\MATLAB\R2015b\toolbox\ident\ident\@iddata\plot.m             % iddata method
C:\MATLAB\R2015b\toolbox\ident\nlident\@idnlhw\plot.m           % idnlhw method
C:\MATLAB\R2015b\toolbox\ident\nlident\@idnlarx\plot.m          % idnlarx method
C:\MATLAB\R2015b\toolbox\robust\rctobsolete\robust\@frd\plot.m  % frd method
C:\MATLAB\R2015b\toolbox\signal\signal\@dspdata\plot.m          % dspdata method
C:\MATLAB\R2015b\toolbox\stats\classreg\@LinearModel\plot.m     % LinearModel method
C:\MATLAB\R2015b\toolbox\matlab\timeseries\@timeseries\plot.m   % timeseries method
C:\MATLAB\R2015b\toolbox\wavelet\wavelet\@wdectree\plot.m       % wdectree method
C:\MATLAB\R2015b\toolbox\wavelet\wavelet\@ntree\plot.m          % ntree method
C:\MATLAB\R2015b\toolbox\wavelet\wavelet\@dtree\plot.m          % dtree method
C:\MATLAB\R2015b\toolbox\wavelet\wavedemo\@wvtree\plot.m        % wvtree method
C:\MATLAB\R2015b\toolbox\wavelet\wavedemo\@rwvtree\plot.m       % rwvtree method
C:\MATLAB\R2015b\toolbox\wavelet\wavedemo\@edwttree\plot.m      % edwttree method

Titus