Identify and strip characters from colums - r

Question

I have a large dataset in which I want identify and remove characters and signs to keep only the number value.
For example I want -£1125.91m to be -1125.91
dataset
Event var1 var2
<fct> <chr> <chr>
1 Labour Costs YoY 13.34m 0.026
2 Unemployment Change (000's) $16.91b -0.449
3 Unemployment Rate -£1125.91m 0.89k
4 Jobseekers Net Change ¥1012.74b 9.56m
At the moment I know how to remove a single character from the column. Like this:
dataset$`var1` <- gsub("k", "", dataset$`var`)
Doing this manually will be a lot of work because the dataset is really big. I was wondering if you can identify and remove all the characters, so also the currency symbols and the m's and b's all at once?
To replicate the dataset:
dataset <- structure(list(Event = structure(2:5, .Label = c("Event", "Labour Costs YoY",
"Unemployment Change (000's)", "Unemployment Rate", "Jobseekers Net Change"),
.Names = c("", "", "", ""), class = "factor"), var1 = c("13.34m", "$16.91b", "-£1125.91m", "¥1012.74b"), var2 = c(0.026, -0.449, "0.89k", "9.56m")), row.names = c(NA,
-4L), class = c("tbl_df", "tbl", "data.frame"))

Answer 1

To remove all but a hyphen, digit or a dot, you can use
dataset$var1 <- gsub("[^-0-9.]", "", dataset$var1)
The [^-0-9.] pattern is a negated character class that matches any char but the ones defined in the class.
See the regex demo online.
See an online R demo:
dataset <- structure(list(Event = structure(2:5, .Label = c("Event", "Labour Costs YoY",
"Unemployment Change (000's)", "Unemployment Rate", "Jobseekers Net Change"),
.Names = c("", "", "", ""), class = "factor"), var1 = c("13.34m", "$16.91b", "-£1125.91m", "¥1012.74b"), var2 = c(0.026, -0.449, "0.89k", "9.56m")), row.names = c(NA,
-4L), class = c("tbl_df", "tbl", "data.frame"))
gsub("[^-0-9.,]", "", dataset$var1)
## => [1] "13.34" "16.91" "-1125.91" "1012.74"