How do I make a logamarithic curved line of best fit?

This is my Code:

Stim=[200 250 350 600];

Volt_Max=[max(mV200(:,3)) max(mV250(:,3)) max(mV350(:,3)) max(mV600(:,3))];

plot(Stim,Volt_Max,'h')

ylabel('Voltage (mV)')

xlabel('Stimulus Voltage (mV)')

xlim([200 700])

title('Effect of Stimulus Intensity on Active Propagations')

grid on

logx=log(Stim)

logy=log(Volt_Max)

Const=polyfit(logx, logy, 6)

hold on

plot(Stim, exp(polyval(Const, logx)));

I want a curved plot, however, the plot I get becomes this:

Answer 1

[Durganshu]

You can manually code the problem to store more intermediate values through interpolation in order to make the curve more smooth. Predefined function pchip can be used for this. Read the documentation here: https://in.mathworks.com/help/matlab/ref/pchip.html

You can also use teh Curve Fitting toolbox for your purpose. Read this documentation: https://in.mathworks.com/help/curvefit/curve-fitting.html

The easiest way to solve this issue and get a smooth curve will be to perform interpolation and obtain more values between two data points (marked with 'o' on the shown graph). This will definitely smoothen the curve.