How to fit irregular data using Lowess/other correct method?

Hello, I really need some help- I have got two design variables with irrengular pattern.I wish to build a MATLAB code to establish a smooth relation and generate a relationship. I also want to plot and double-check that I have built it right. Can someone please tell how do I do it- is Lowess the best method to fit this curve? Thanks, Swanand.

Answer 1

[Image Analyst]

Lowess is a good method if you have the curve fitting toolbox. I don't, so I use the Savitzky-Golay filter, sgolayfilt() in the Signal Processing Toolbox. Or maybe a median filter will do the trick for you. It's claim to fame is it gets rid on impulsive noise while keeping true edges sharp.

[Swanand Kulkarni]

Hello, thanks a lot for your answer. I am using CFtool box and finding it really hard to fit my data in. Also, I need a relationship between the variables after plotting them. Is there any MATLAB which can do that? Thanks again!!!

[Image Analyst]

You can use fitlm() or fitglm() in the Stats toolbox.