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rstringregressionformula

How to run regression when formula is given by a string?

Let's consider data following:

set.seed(42)
y <- runif(100)
df <- data.frame("Exp" = rexp(100), "Norm" = rnorm(100), "Wei" = rweibull(100, 1))

I want to perform linear regression but when formula is a string in format:

form <- "Exp + Norm + Wei"

I thought that I only have to use:

as.formula(lm(y~form, data = df))

However it's not working. The error is about variety in length of variables. (it seems like it still treats form as a string vector of length 1, but I have no idea why).

Do you know how I can do it ?

Solution

  • We can use paste to construct the formula, and use it directly on lm

    lm(paste('y ~', form), data = df)

    -output

    #Call:
#lm(formula = paste("y ~", form), data = df)

#Coefficients:
#(Intercept)          Exp         Norm          Wei  
#   0.495861     0.026988     0.046689     0.003612