I have several cases where I am trying to save a vector of elements to my global environment to be able to use for querying a database or other subsequent analyses.
As an example, I have a dataframe below, but in reality my data consists of thousands of values.
df:
example start stop range
set1 1 4180 1:4180
set2 460 499 460:499
set3 1 1127 1:1127
set4 1128 1622 1128:1622
set5 3741 3748 3741:3748
With this dataframe I want to capture every integer between start and stop, so I would like to use the range column to create a vector of every integer.
I have been using:
cat(paste0(df$range, collapse = ", "))
Which then prints to the console:
1:4180, 460:499, 1:1127, 1128:1622, 3741:3748
I have then been copy/pasting that output to save it as a vector in my global environment:
nums <- c(1:4180, 460:499, 1:1127, 1128:1622, 3741:3748)
Once I have this vector I can then do additional analyses such as:
> length(nums)
[1] 5850
> length(unique(nums))
[1] 4180
> summary(nums)
Min. 1st Qu. Median Mean 3rd Qu. Max.
1 712 1443 1727 2726 4180
etc. etc.
Is there a simple way to skip the copy/paste step and save my desired formatting as a vector directly?
An option is Map to get the sequence (:) between the corresponding 'start', 'stop' values and unlist the list of vectors to a single vector.
vec <- unlist(Map(`:`, df$start, df$stop))
Or if we want to use the 'range' column, then evaluate it
vec1 <- sapply(df$range, function(x) eval(parse(text = x)))