[R] Beginning lm

rkevinburton at charter.net rkevinburton at charter.net
Sat Jul 26 17:37:54 CEST 2008

I have ussed lm to generate a basic line correlation:

fit = lm(hours.of.sleep ~ ToSleep)

Note: From "Bayesian Computation with R", Jim Albert, p. 7

I understand the simple y = mx + b line that this fits the data to. Now apparently I don't understand formulas. The documentation indicates that there is an implied "intercept" in the formula so now I want to try and fit the line to a second degree polynomial so I tried:

ft = lm(hours.of.sleep ~ ToSleep ^ 2 + ToSleep)

and I still seem to get results that indicate a slope intercept, y = mx + b, type of fit. Can anyone give me a short tutorial on the formula syntax? I would like to fit the data to 2nd and higher order polynomials, 1 / x, log(x), etc. I am sorry but I could not glean this information from the help page on lm.

Thank you.


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