Two curves in one plot with wrong scaling

I want to show the measurement results of two measurements with a fitting curve in a plot. Now I want both values to start at x-value 1 and end at 13. I tried to do this with xticks and xticklabels, which has worked wonderfully so far. By adding the spline (from the curvefitting toolbox) I can no longer do it with the second value (y2).

Does anyone have an idea where the failure lies?

Here is the sample code:

y1= [ 1 2 3 4 5 6 7 8 9 10 11 12 13]
y2= [ 10 20 30 40 50 60 70 80 90 100 110 120 130]

ft = fittype( 'smoothingspline' );
opts = fitoptions( 'Method', 'SmoothingSpline' );

f = figure(1); 
set(f, 'Units', 'normalized', 'Position', [0.1, 0.1, 0.7, 0.7]); 
opts.SmoothingParam = 1;
[xData, yData] = prepareCurveData( [], y1 )
[fitresult, gof] = fit( xData, yData, ft, opts );
plot(fitresult,'b')
hold on
[xData, yData] = prepareCurveData( [], y2 )
[fitresult, gof] = fit( xData, yData, ft, opts );
plot(fitresult,'r')
grid on
legend('y1','y2')
xticks([0 1 2 3 4 5 6 7 8 9 10 11 12 13 14])
xticklabels({'',1,2,3,4,5,6,7,8,9,10,11,12,13,0})

Answer 1

[darova]

Use function that fit() returns

[fitresult, gof] = fit( xData, yData, ft, opts );
% plot(fitresult,'r')
plot(xData,fitresult(xData),'r')

[Mepe]

Many thanks for your response!

The scaling now fits perfectly!

Unfortunately the curve smoothing no longer works (cou can't see it with my trivial example). Do you have an idea why?

[darova]

You can manually enable this feature. Try:

plot(x,y,'linesmoothing','on')

[Mepe]

Sorry, I do not understand that. Shouldn't the smoothed lines already be called up via "fitresult"?

The Code

plot(xData,fitresult(xData),'b','linesmoothing','on')

also only delivers the original data...

[darova]

Can you please specify what do you mean by "smooth"?

[darova]

What about manual spline?

[fitresult, gof] = fit( xData, yData, ft, opts );
% plot(fitresult,'r')
x1 = linspace(xData(1),xData(end),100);
y1 = spline(xData,fitresult(xData),x1);
plot(xData,fitresult(xData),'.r')
hold on
plot(x1,y1,'b')
hold off

Answer 2

[Mepe]

I generated a spline code using the curve fitting toolbox:

ft = fittype( 'smoothingspline' );
opts = fitoptions( 'Method', 'SmoothingSpline' );
opts.SmoothingParam = 1;
[xData, yData] = prepareCurveData( [], y1 )
[fitresult, gof] = fit( xData, yData, ft, opts );
plot(fitresult,'b')