I need to change a row where if I have an n/a or null, I get a 0 and if I have a character in it, I get a 1, I am drawing a blank on it, when I tried the replace on is.na_replace no luck.

I have the following in the column

""    "h"   "t"   "tp"  "tb"  "p"   "b"   "ht"  "v"   "hb"  "et"  "hp"  "tv"  "e/s" "bp" 
 "e"   "htp" "eb"  "hv"  "etb" "he"  

any ideas?

CodePudding user response：

vec <- c("",    "h",   "t",   "tp")
 (!is.na(vec) & nzchar(vec))
# [1] 0 1 1 1

• nzchar(vec) returns logical (true/false) based on whether there are any characters in each string; it is analogous to nchar(vec) > 0, where nchar("") is 0;
• however, if any of vec are NA, they are silently converted to "NA" internally, which has 2 characters in it; to preclude this, we preface that with !is.na(vec)
• (...) where ... is a logical expression is a shortcut for converting a logical vector to integer. See TRUE and FALSE.

It could also have been done with an ifelse (or replace or dplyr::if_else or data.table::fifelse), which in this case is fine, but I don't think it adds much value while it does add overhead to the call-stack.

CodePudding user response：

Another way you can do this with dplyr:

df <- data.frame(s = c("", "hdsa", "t", "tp", "tb"))
df %>%
  mutate(new_col = ifelse(
    nchar(s) > 0,
    1,
    0
  ))

     s new_col
1            0
2 hdsa       1
3    t       1
4   tp       1
5   tb       1

CodePudding user response：

Here is a tidyverse approach:

library(dplyr)
library(stringr)
library(tibble)

vec <- c("",    "h",   "t",   NA)

tibble(vec) %>% 
  mutate(new_col = case_when(vec == "" | is.na(vec) ~ "0",
                             str_detect(vec, '[A-Za-z]') ~ "1"))

  vec   new_col
  <chr> <chr>  
1 ""    0      
2 "h"   1      
3 "t"   1      
4  NA   0 

CodePudding user response：

Try this

#first rty this,it will replace NA to 0

    df%>% mutate_at(vars(column,row with na),~replace(.,is.na(.), 0))

and use gsub function to replace characters with what you want
see samples below


# consider a string "Python and java"
# replace the character 'a' in  "Python and java"
# with "M"

      print(sub("a", "M", "Python and java") )

you get "Python and java"

I hope it works