Re: [R] how to extract strings in any column and in any row that start with

Hi Rui, thank you so much that is exactly what I needed! Cheers, Ana On Fri, May 15, 2020 at 5:12 PM Rui Barradas wrote: > > Hello, > > I have tried several options and with large dataframes this one was the > fastest (in my tests, of the ones I have tried). > > > s1 <- sapply(tot, function(x)

Re: [R] how to extract strings in any column and in any row that start with

Hello, I have tried several options and with large dataframes this one was the fastest (in my tests, of the ones I have tried). s1 <- sapply(tot, function(x) grep('^E10', x, value = TRUE)) Then unlist(s1). A close second (15% slower) was s2 <- tot[sapply(tot, function(x) grepl('^E10',

Re: [R] how to extract strings in any column and in any row that start with

> How would I extract from it all strings that start with E10? Hi Ana, Here's a simple solution: x <- c ("P24601", "E101", "E102", "3.141593", "E101", "xE101", "e103", " E104 ") x [substring (x, 1, 3) == "E10"] You' will need to replace x with another *character vector*. (As

Re: [R] how to extract strings in any column and in any row that start with

This is almost certainly not the most efficient way: tot <- data.frame(v1 = paste0(LETTERS[seq(1:5)],seq(1:10)), v2 = paste0(LETTERS[seq(1:5)],seq(from = 101, to=110, by = 1)), v3 = paste0(LETTERS[seq(1:5)],seq(from = 111, to=120, by = 1)), v4 =

Re: [R] how to extract strings in any column and in any row that start with

If you want to treat your data frame as if it were a vector, then convert it to a vector before you give it to grep. unlist(tot) On May 15, 2020 12:24:17 PM PDT, Ana Marija wrote: >Hello, > >this command was running for more than 2 hours >grep("E10",tot,value=T) >and no output > >and this

Re: [R] how to extract strings in any column and in any row that start with

Hello, this command was running for more than 2 hours grep("E10",tot,value=T) and no output and this command df1 <- tot %>% filter_all(any_vars(grepl( '^E10', .))) gave me a subset (a data frame) of tot where ^E10 what I need is just a vector or all values in tot which start with E10. Thanks

Re: [R] how to extract strings in any column and in any row that start with

Read about regular expressions... they are extremely useful. df1 <- tot %>% filter_all(any_vars(grepl( '^E10', .))) It is bad form not to put spaces around the <- assignment. On May 15, 2020 10:00:04 AM PDT, Ana Marija wrote: >Hello, > >I have a data frame: > >> dim(tot) >[1] 502536 1093 >

[R] how to extract strings in any column and in any row that start with

Hello, I have a data frame: > dim(tot) [1] 502536 1093 How would I extract from it all strings that start with E10? I know how to extract all rows that contain with E10 df0<-tot %>% filter_all(any_vars(. %in% c('E10'))) > dim(df0) [1] 5105 1093 but I just need a vector of strings that start