9

Do comments slow down R?

This question has been asked twice on StackOverflow regarding python:

Do comments slow down an interpreted language? Will excessive commenting of code slow execution?

For python the answer appears to be 'no'. I do not know enough about the differences between the two languages to know how relevant those answers are for R.

Here is a similar question about white space in R. Again the answer appears to be 'no'.

does white space slow down processing

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Mark Miller
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1 Answers1

6

For R the answer appears to be 'yes', unless I made a mistake somewhere below.

# Time difference of 21.84725 secs
# Time difference of 24.05738 secs

# total.time.2 - total.time.1
#
# Time difference of 2.210126 secs

n <- 280

start.time.1 <- Sys.time()

b <- 2

for(i in 1:n) {
     for(j in 1:n) {
          for(k in 1:n) {

               b <- b + 2 - 1 - 0.75

          }
     }
}

b

end.time.1 <- Sys.time()

total.time.1 <- end.time.1 - start.time.1
total.time.1


start.time.2 <- Sys.time()

b <- 2

# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.


for(i in 1:n) {

# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.

     for(j in 1:n) {

# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.

          for(k in 1:n) {

# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.

               b <- b + 2 - 1 - 0.75

# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.
# I wonder whether comments slow down R.  Here are some comments.  Let's see.

          }
     }
}

b

end.time.2 <- Sys.time()

total.time.2 <- end.time.2 - start.time.2

total.time.1
total.time.2

total.time.2 - total.time.1
Mark Miller
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    yes, indeed for example when creating a package, R removes all comments.This is why I've never seen a function inside R (eg giving `ls` to prompt) that has a line of comment. – Luca Braglia Apr 09 '14 at 19:22