Predict with linear model from another table with R

Question

Hi all I am new to R and I need to know how to use the predict function with tables.

I have a first table with some weather variables ( wind, temperature, pressure ) and with the consumption of a building. I have created a lineal model doing this:

mymodel<-lm(energyConsum ~ temperature + pressure+ wind, data=mytable)

And I have a second table with the weather prediction, with the values temperature, wind and pressure variables, and I want to predict the consumption

I know that I have to use the function predict() , and set mymodel , but I don't really know how to do it to create a new column with all the predictions (by line).

cheers

Answer 1

I don't have your data, but here's an example with mtcars .

You can use predict.lm 's second argument, newdata , to make predictions on a data.frame. You can then assign these results to a new column.

Example:

train <- mtcars[1:20, ]
test  <- mtcars[21:32,]

mymodel   <- lm(mpg ~ cyl + disp + hp, data=train)
test$pred <- predict(mymodel, test)