How do I prevent R function "step" from outputing to the console?

Question

The step function always prints the result of each stepwise regression to the console, even if the executed statement is an assignment, not evaluation. How do I make it just silently select predictors, without printing anything?

Answer 1

In the help file of function step() you can find that there is argument trace=. If you set this argument to 0 then only final predictors are printed or if you use step() in assignment then nothing is printed.

Modified example from help file:

summary(lm1 <- lm(Fertility ~ ., data = swiss))
slm1 <- step(lm1,trace=0)
summary(slm1)

Or

step(lm1, trace=0)

Call:
lm(formula = Fertility ~ Agriculture + Education + Catholic + 
    Infant.Mortality, data = swiss)

Coefficients:
     (Intercept)       Agriculture         Education          Catholic  
         62.1013           -0.1546           -0.9803            0.1247  
Infant.Mortality  
          1.0784