Contents
How to plot an exponential curve in R?
An exponential y = y 0 exp x. (Note: this is corrected over first posting.) This is more a comment but I’m making it an answer so I can show the picture. This data doesn’t seem to be fitted by an exponential curve. In fact, if you look at log (y) vs x, it has got a pretty clear kink in it at around x=8 or x=9.
How is linear regression used in real life?
Linear regression is a very powerful statistical technique as it can be used to describe more complicated functions (such as exponential or power functions) by linearizing the data sets in question.
Which is the asymptotic regression function for curve fitting?
The solution is to use a self-starting function, a special function for curve fitting that guesses its own start parameters. The asymptotic regression function, SSasymp is equivalent to our exponential decay: it searches for the logarithm of α: From the fit result, you can plot the fitted curve, or extract whichever information you need:
How is an exponential function treated as a model?
We set up a grid of points and superpose the exponential function on the previous plot. An exponential function in the Time variable can be treated as a model of the log of the Counts variable. This model is pretty good, though it explains about 81% of the variance by comparison with the 89% explained by the quadratic model.
What happens when we convert exponential data to linear data?
To be done later, though one comment: when we convert exponential data to linear data, because we are taking the logarithm of each of the y values, the resulting curve minimizes the sum of the squares of the logarithms of the errors, not the sum of the squares of the errors themselves, so the fit will be much more tight for smaller values.
How to scale back the’y’predicted result?
Any tip is welcome. Thank you very much. Bit late to the game: Just don’t scale your y. With scaling y you actually loose your units. The regression or loss optimization is actually determined by the relative differences between the features. BTW for house prices (or any other monetary value) it is common practice to take the logarithm.
How to transform an exponential function into a linear sum?
We want to be able to transform the exponential function into a linear sum of functions. Here we will look at some transformations which may be used to convert such data so that we may use the least squares method to find the best fitting curve.