how to find curve fit for my plot?

I have this plot in which I have plotted signal intensity vs time, but my plot does not look how it is supposed to (fig 2) instead it looks like fig 1.

so what I want to do is to find a function by curve fitting the points that I have already and then plotting the remaining points in the function to complete the curve. Ive tried using the cftool in matlab but I did not have any luck finding a function that would fit to my data.

[KSSV]

What you are looking for is extrapolation....you cannot expect the same result as you have shown.

[Raheema Al Karim Damani]

oh yes, can you advise me on what kind of function I could use with this plot, to gather the extrapolated points?

Answer 1

[Monisha Nalluru]

In order to get the second plot, Pre-processing of data is required. The pre-processed data then can be applied with the functions from Curve Fitting Toolbox such as cfit,sfit etc. After getting the fitting use those co-efficient to get the new signal intensity.

Also refer the following links:

https://www.mathworks.com/help/curvefit/linear-and-nonlinear-regression.html

https://www.mathworks.com/help/curvefit/interpolation.html

[Raheema Al Karim Damani]

Thank you for your response. Can you elaborate what you mean by pre-processing the data? I tried using cfit but I was not able to find any function that would fit my graph.

I was trying to use the slmengine function but I did not have much luck with it. From this graph, I am trying to extract area under curve which is why I do not just simply want to plot arbitrary points to complete the curve.