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    %% Find Coefficient Order to Set Start Points and Bounds  
% For the properties |Upper|, |Lower|, and |StartPoint|, you need to find
% the order of the entries for coefficients.   

% Copyright 2015 The MathWorks, Inc.


%% 
% Create a fit type. 
ft = fittype('b*x^2+c*x+a');  

%% 
% Get the coefficient names and order using the |coeffnames| function. 
coeffnames(ft) 

%%
% Note that this is different from the order of the coefficients in the
% expression used to create |ft| with |fittype|.  

%% 
% Load data, create a fit and set the start points. 
load enso
fit(month,pressure,ft,'StartPoint',[1,3,5]) 

%%
% This assigns initial values to the coefficients as follows: |a = 1|,
% |b = 3|, |c = 5|.  

%% 
% Alternatively, you can get the fit options and set start points and lower
% bounds, then refit using the new options. 
options = fitoptions(ft)
options.StartPoint = [10 1 3];
options.Lower = [0 -Inf 0];
fit(month,pressure,ft,options)