How to reproduce least squares line with a plotted function

[jmichaelrosenberg@gmail.com]

Hi, I have a (possibly embarrassingly simple) question. How can I reproduce the line that I added to a graph using as a least squares lines with a plotted function? I am asking in part because I want to better understand how to plot other functions, i.e., one that will fit this data well! I tried:

 

f() = b + x

f() = x

But, these didn’t seem to do the trick. Thank you.

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   Screen-Shot-2019-05-27-at-7.51.00-AM.png
   

[Bill Finzer]

Hi,

The following should work:

2.39*x-5.6

2.39*Day-5.6

Or you could create two sliders, a and b, adjusted to -5.6 and 2.39. Then you would plot

b + a*Day or

b + a*x

I hope that helps,

Bill

[jrosenb8@utk.edu]

Thanks – that did the trick.

Is it possible (or on the docket) to facilitate adding a line of best fit that uses a function other than a linear model (i.e., could you fit a quadratic function)?

Thank you very much!

Josh

[Bill Finzer]

Hi Josh,

It is possible, of course to add quadratic fitting. That starts us down a slippery slope, though, that includes polynomial fitting and exponential/logarithmic fitting. All that functionality can be pretty off-putting to non-math-geeks. So we’d have to figure out how to provide it without cluttering things up. Maybe in a plugin?!

Bill

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