Linear Model
Formal Definition
General Linear Model
General Linear Model Can transform the predictor values to linearize the relationship between the predictors and the response Also changes the variance so it only should be done if the variance is not uniform and is made uniform by the transform
Polynomial Regression
Need More Not all phenomenon follow linear response Not all residuals are normally distributed This leads: –GLMs: Single function, specified regression distribution –GAMs: Multiple functions –“Non-parametric” approaches: function is determined by the computer
GLM
Generalized Linear Models
Common Functions in R Probability Distribution (Link Function) Binomial (link = "logit") –True/false, alive/dead Gaussian (link = "identity") –Continuous, normal Gamma (link = "inverse") –Seed distribution, distance from… Poisson (link = "log") –Counts
Normal Distribution WikipediaAKA “Gaussian” Distribution
Binomial Number of successes of yes/no experimentsWikipedia
Poisson Number of events in time T, k=number of occurrences Wikipedia
Gamma Distribution Wait times, seed distribution, etc. Wikipedia
Deviance
Degrees of Freedom