Force R to display the output rounded with 3 digits

I using R with Rstudio. I want to change the default behavior of R,preferably via options(), to show the numeric results of the output (ie, the values printed in the console) rounded with 3 decimal digits.

I know that I can use
round( x, digits = 3) command, but my objective is to compare "by eye" several variables, and enclosing all variables with the "round" (or "format") command is cumbersome.

An example of what I want:
I want to the command matrix(c(0.00003,0.1111111),ncol=1) give the output:

        [,1] 
   [1,] 0.000
   [2,] 0.111

I try to use options(digits=3), but with that command, some results are displayed in scientific notation. I also try options(digits=3, scipen = 999) but the scipen argument makes the R to print more decimal places in the output.

Ps.: I want to change only the output, not the variable values.

You can consider the following approach to define a new class with a different print method :

library(stringr)
options(myMatDigit = 3)

print.myMat <- function(mat)
{
  myMatDigits <- getOption("myMatDigit")
  nb_Col <- ncol(mat)
  nb_Row <- nrow(mat)

  for(i in 1 : nb_Col)
  {
    mat_Char[, i] <- round(mat[, i], digits = myMatDigits)
  }
  
  print(mat_Char)
}

mat <- matrix(c(0.00003, 0.1111111), ncol = 1)
mat <- structure(mat, class = "myMat")

mat

     [,1]
[1,] 0.000
[2,] 0.111

With this approach, you can set a global option with myMatDigit that you can use in the class afterwards.

R actually tries to help you here but showing the default number of digits, and offers different ways to influence this as you saw.

However, sometimes we want to override this in a 'brute force way'. One possible way is to round():

> matrix(c(0.00003,0.1111111),ncol=1)   # your example
         [,1]
[1,] 0.000030
[2,] 0.111111
>
> round(matrix(c(0.00003,0.1111111),ncol=1), digits=3)
      [,1]
[1,] 0.000
[2,] 0.111
> 

If you want to automate this you could create a new type myMatrix which inherits from matrix, and overwrites its print method by one that rounds as shown here.