gsub

I am reading in a bunch of CSVs that have stuff like "sales - thousands" in the title and come into R as "sales...thousands". I'd like to use a regular expression (or other simple method) to clean these up. I can't figure out why this doesn't work: #mock data a <- data.frame(this.is.fine = letters[1:5], this...one...isnt = LETTERS[1:5]) #column names colnames(a) # [1] "this.is.fine" "this...one...isnt" #function to remove multiple spaces colClean <- function(x){ colnames(x) <- gsub("\\.\\.+", ".", colnames(x)) } #run function colClean(a) #names go unaffected colnames(a) # [1] "this.is.fine"

I have some sentences like this one. c = "In Acid-base reaction (page[4]), why does it create water and not H+?" I want to remove all special characters except for '?&+-/ I know that if I want to remove all special characters, I can simply use gsub("[[:punct:]]", "", c) "In Acidbase reaction page4 why does it create water and not H" However, some special characters such as + - ? are also removed, which I intend to keep. I tried to create a string of special characters that I can use in some code like this gsub("[special_string]", "", c) The best I can do is to come up with this cat("!\"#$%()*,

I have lines with a single : and a ' in them that I want to get rid of. I want to use awk for this. I've tried using: awk '{gsub ( "[:\\']","" ) ; print $0 }' and awk '{gsub ( "[:\']","" ) ; print $0 }' and awk '{gsub ( "[:']","" ) ; print $0 }' non of them worked, but return the error Unmatched ". . when I put awk '{gsub ( "[:_]","" ) ; print $0 }' then It works and removes all : and _ chars. How can I get rid of the ' char? Dimitre Radoulov You could use: Octal code for the single quote: [:\47] The single quote inside double quotes, but in that case special characters will be expanded by the

I am trying to write a function which does different things, depending on the second argument. But I am getting an error all the time. Depending on the dimension of the matrix, the function should perform different tasks. Here is an example x<-cbind(X1,X2,X3) function<-function(x,hnrstr){ if (hnrstr<-1){ x<-data.frame(X1=x[1],X2=x[2],X3=x[3]) y<-x y[ ,"X2","X3"]<- gsub(" {2, }"," ",y[ ,"X2","X3"]) } if (hnrstr<-2){ x<-data.frame(X1=x[1],X2=x[2]) P<-x } if (hnrstr<-1){ x<-y } if (hnrstr<-2){ x<-P } return(x) } apply(x,c(3,3), function(x,1)) I am getting the error: Error in drop && !has.j :

In order to be able to process I'd like to replace the first occurrence of a : in a string (which is my marker, that a speech begins). text <- c("Mr. Mark Francois (Rayleigh) (Con): If the scheme was so poorly targeted, why were the Government about to roll it out to employees in the Department of Trade and Industry and the Department for Work and Pensions on the very day the Treasury scrapped it? The CBI and the TUC have endorsed the scheme, which has helped 500,000 people and their families to improve their computer skills. When the Chancellor announced the original concession, he told the

New to R. I am looking to remove certain words from a data frame. Since there are multiple words, I would like to define this list of words as a string, and use gsub to remove. Then convert back to a dataframe and maintain same structure. wordstoremove <- c("ai", "computing", "ulitzer", "ibm", "privacy", "cognitive") a id text time username 1 "ai and x" 10 "me" 2 "and computing" 5 "you" 3 "nothing" 15 "everyone" 4 "ibm privacy" 0 "know" I was thinking something like: a2 <- apply(a, 1, gsub(wordstoremove, "", a) but clearly this doesnt work, before converting back to a data frame. wordstoremove

I have a column containing values of 3 strings separated by semicolons. I need to just extract the first part of the string. Type <- c("SNSR_RMIN_PSX150Y_CSH;SP_12;I0.00V50HX0HY3000") What I want is: Get the first part of the string (till the first semicolon). Output : SNSR_RMIN_PSX150Y_CSH I tried gsub but not able to understand. Kindly let me know how we can do this efficiently in R. You could try sub sub(';.*$','', Type) #[1] "SNSR_RMIN_PSX150Y_CSH" It will match the pattern i.e. first occurence of ; to the end of the string and replace with '' Or use library(stringi) stri_extract(Type,

I've been trying to remove the white space that I have in a data frame (using R) . The data frame is large (>1gb) and has multiple columns that contains white space in every data entry. Is there a quick way to remove the white space from the whole data frame? I've been trying to do this on a subset of the first 10 rows of data using: gsub( " ", "", mydata) This didn't seem to work, although R returned an output which I have been unable to interpret. str_replace( " ", "", mydata) R returned 47 warnings and did not remove the white space. erase_all(mydata, " ") R returned an error saying 'Error: