Unable to update values in a column based on pattern match of another column in a dataframe in R

[ritm]

I have a dataframe in R which has two columns Machine Name(character) and Region(factor).They have values as follows(few examples):

Machine Name Region
1233.corp.pdo.om APAC
xyz.om Europe
345.corp.pdo.cm Europe
abc12.cm Americas

So i want to update the region with pdo for the machines which have corp.pdo in them.But when i am trying to update its not happening using if else.Can you please help.

[siddharthprabhu]

Something like this?

library(dplyr, warn.conflicts = FALSE)
library(stringr)

df <- tribble(~ `Machine Name`, ~ Region,
              "1233.corp.pdo.om", "APAC",
              "xyz.om", "Europe",
              "345.corp.pdo.cm", "Europe",
              "abc12.cm", "Americas")

mutate(df, Region = if_else(str_detect(`Machine Name`, "corp.pdo"), "pdo", Region))
#> # A tibble: 4 x 2
#>   `Machine Name`   Region  
#>   <chr>            <chr>   
#> 1 1233.corp.pdo.om pdo     
#> 2 xyz.om           Europe  
#> 3 345.corp.pdo.cm  pdo     
#> 4 abc12.cm         Americas

^{Created on 2020-07-20 by the reprex package (v0.3.0)}

[ritm]

Yes like this only.Let me try this.Hope this works.I will update you.Thanks.

[ritm]

@siddharthprabhu

mutate(df, Region = if_else(str_detect(Machine Name, "corp.pdo"), "pdo", Region))

I get the following error:

Error: false must be a character vector, not a factor object

Its got to do with Region column i guess which is a factor type.

[siddharthprabhu]

Indeed. I missed the part where you stated that Region is a factor. The simplest workaround is to coerce it into a character vector. You can always convert it back to factor later with pdo added as a new level if necessary.

df %>% 
  mutate(Region = as.factor(Region)) %>% 
  mutate(Region = if_else(str_detect(`Machine Name`, "corp.pdo"), "pdo", as.character(Region)))
#> # A tibble: 4 x 2
#>   `Machine Name`   Region  
#>   <chr>            <chr>   
#> 1 1233.corp.pdo.om pdo     
#> 2 xyz.om           Europe  
#> 3 345.corp.pdo.cm  pdo     
#> 4 abc12.cm         Americas

[ritm]

I tried doing that.Although it doesn't throw any error but it doesn't update the values for those records.
Code:-

df3_machine_region %>%mutate(Region= ifelse(str_detect(Machine.Name, "corp.pdo"), "pdo", as.character(Region)))

Output:(sample)
Machine Name Region
D120710.corp.pdo.om
Europe

D120867.corp.pdo.om
Americas

[siddharthprabhu]

Not sure about that. It would help if you could post a self-contained reproducible example with a subset of your data.

FAQ: How to do a minimal reproducible example ( reprex ) for beginners

A minimal reproducible example consists of the following items: A minimal dataset, necessary to reproduce the issue The minimal runnable code necessary to reproduce the issue, which can be run on the given dataset, and including the necessary information on the used packages. Let's quickly go over each one of these with examples: Minimal Dataset (Sample Data) You need to provide a data frame that is small enough to be (reasonably) pasted on a post, but big enough to reproduce your issue. Let's say, as an example, that you are working with the iris data frame head(iris) #> Sepal.Length Sepal.Width Petal.Length Petal.Width Species #> 1 5.1 3.5 1.4 0.2…