Published On Jun 23, 2017
Le module 1 de la serie des modèles de regression linéaire dans Rstudio
LINEAR REGRESSION MODELS IN R
1. Load and read data
library(readxl)
Database = read_excel("states.data.xlsx", col_names = TRUE, col_types = NULL, na="", sheet="states", skip = 0)
2. Simple linear regression
2.1 Examine the data before fitting models
summary of expense and csat columns, all rows
data.ex.csat = subset(Database, select = c("expense", "csat"))
summary(data.ex.csat)
correlation between expense and csat
cor(data.ex.csat)
2.2 Plot the data before fitting models : scatter plot of expense vs csat
plot(data.ex.csat)
2.3 Linear regression example
Fit our regression model
sat.mod1 = lm(csat ~ expense, data=Database)
summary(sat.mod1)
Regression csat vs percent
data.per.csat = subset(Database, select = c("percent", "csat"))
summary(data.per.csat)
cor(data.per.csat)
plot(data.per.csat)
sat.mod2 = lm(csat ~ percent, data=Database)
summary(sat.mod2)
anova(sat.mod1, sat.mod2)
AIC(sat.mod1, sat.mod2)