I'm looking to do polynomial regression on 2 relatively uncorrelated features. Even with very high degrees, I find that the model doesn't fit very well to the data (figure attached here). Since the number of degrees is the only parameter that I can modify, I am looking to know if polynomial regression only works with highly correlated variables?
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$\begingroup$ What do the various colors represent? Linear regression assumes that there is a linear relation between the variables (similar for polynomial). If this is not the case then you have the wrong model. $\endgroup$– user2974951Sep 20, 2019 at 6:14
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1$\begingroup$ This is a nice example of why polynomial regression can be a horrible regression procedure: the right tail of the fit is determined primarily by the data at the extreme left. It's obviously a terrible description of the right-hand points. It's likely you will learn far more by choosing effective plots of the data and looking at them closely before continuing: consider using logarithmic or square root scales on both axes. $\endgroup$– whuber ♦Sep 20, 2019 at 14:26