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Let's imagine you have a string:
strLine <- "The transactions (on your account) were as follows: 0 3,000 (500) 0 2.25 (1,200)" Is there a function that strips out the numbers into an array/vector producing the following required solution:
result <- c(0, 3000, -500, 0, 2.25, -1200)? i.e.
result[3] = -500 Notice, the numbers are presented in accounting form so negative numbers appear between (). Also, you can assume that only numbers appear to the right of the first occurance of a number. I am not that good with regexp so would appreciate it if you could help if this would be required. Also, I don't want to assume the string is always the same so I am looking to strip out all words (and any special characters) before the location of the first number.
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To convert strings to integers in R, use the strtoi() function. The strtoi() is a built-in function that converts strings to integers. The strtoi() function accepts two arguments and returns the integers.
How to remove a character or multiple characters from a string in R? You can either use R base function gsub() or use str_replace() from stringr package to remove characters from a string or text.
Using the substr() function We can get the first character of a string by using the built-in substr() function in R. The substr() function takes 3 arguments, the first one is a string, the second is start position, third is end position.
library(stringr) x <- str_extract_all(strLine,"\\(?[0-9,.]+\\)?")[[1]] > x [1] "0" "3,000" "(500)" "0" "2.25" "(1,200)" Change the parens to negatives:
x <- gsub("\\((.+)\\)","-\\1",x) x [1] "0" "3,000" "-500" "0" "2.25" "-1,200" And then as.numeric() or taRifx::destring to finish up (the next version of destring will support negatives by default so the keep option won't be necessary):
library(taRifx) destring( x, keep="0-9.-") [1] 0 3000 -500 0 2.25 -1200 OR:
as.numeric(gsub(",","",x)) [1] 0 3000 -500 0 2.25 -1200 Here's the base R way, for the sake of completeness...
x <- unlist(regmatches(strLine, gregexpr('\\(?[0-9,.]+', strLine))) x <- as.numeric(gsub('\\(', '-', gsub(',', '', x))) [1] 0.00 3000.00 -500.00 0.00 2.25 -1200.00 If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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