Insert variable within " " character string

Question

Ok so I am writing this loop which I intend to loop through and paste the name from my vector into the loop. The intended destination for the paste of the variable name is to be within a URL link and also a destfile name between " " marks.

So far this is my procedure:

    # Download ETF AUM Files 
    file.list <- c("DDM","MVV","QLD","SAA","SSO","TQQQ","UDOW","UMDD","UPRO","URTY","UWM", "BIB", "FINU","LTL","ROM", "RXL", "SVXY","UBIO","UCC","UGE","UPW","URE","USD","UXI","UYG","UYM","DOG","DXD","MYY","MZZ","PSQ","QID","RWM","SBB","SDD","SDOW","SDS","SH","SPXU","SQQQ","SRTY","TWM","SMDD","UVXY","VIXM","VIXY")


    # Loop 
     for (f in 1:length(file.list)) {
        next.file <- file.list[i]
        file.name.variable <- paste(next.file[1])
        url <- "https://accounts.profunds.com/etfdata/ByFund/file.name.variable-historical_nav.csv"
        destfile <- "C:/R Projects/Data/etf_aum/file.name.variable.csv"
        download.file(url, destfile, mode="wb")
}

As you can see... I wish to enter the name of my variable inside the vector and paste into into my character strings for the url and destfile... Is there any way to do this?

Right now it wouldn't recognize that I wish the name to be a variable, as its already in " " marks it would take it as its written.

kangaroo_cliff · Accepted Answer · 2017-10-14 03:07:14Z

4

It seems this is what you are after.

for (i in 1 : length(file.list)) {
  file.name.variable <-  file.list[i]

  url <- paste0("https://accounts.profunds.com/etfdata/ByFund/", 
                   file.name.variable, "-historical_nav.csv")

  destfile <- paste0("C:/R Projects/Data/etf_aum/",
                          file.name.variable, "csv")

  download.file(url, destfile, mode="wb")
}

answered Oct 14, 2017 at 3:07

kangaroo_cliff

6,2523 gold badges33 silver badges45 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Andrew Bannerman Over a year ago

Awesome! So all I needed was to ",file.name.variable," inserted unto my " " strings -fantastic - thank you, learn something new every day + the paste0 to remove my sep""

Rich Scriven Over a year ago

paste is vectorized. So it would be more efficient to create the urls and destfiles outside the loop

Collectives™ on Stack Overflow

Insert variable within " " character string

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related