How to apply fit-function on variable

So I've got a fit done with cftool:

%% Fit: 'untitled fit 1'.
[xData, yData] = prepareCurveData( N, A );

% Set up fittype and options.
ft = fittype( 'poly6' );

% Fit model to data.
[fitresult, gof] = fit( xData, yData, ft );

% Plot fit with data.
figure( 'Name', 'untitled fit 1' );
h = plot( fitresult, xData, yData );
legend( h, 'A vs. N', 'untitled fit 1', 'Location', 'NorthEast', 'Interpreter', 'none' );
% Label axes
xlabel( 'N', 'Interpreter', 'none' );
ylabel( 'A', 'Interpreter', 'none' );
grid on
hold on

Now I want the fit-function to be applid on a variable, let's say y. Hence fit-function(y). For example if the fit-function would go like fit = m*x +n, I'd like to reform it to fit = m*y + n. Thanks in advance and appologies for the 3th question asked in such a short period of time.

Answer 1

[Aditya Patil]

You can pass the new data to the fitobject. See the example below,

x = sin(1:10)';
x2 = cos(1:10)';
y = (1:10)';
curve = fit(x, y, 'poly2');
y2 = curve(x2);

Here y2 is calculated from the function fit on x.

[Niklas Kurz]

Thank you. I asked this question in a state of total inexperience. After dealing with Matlab daily its beauty is being more and more revealed.