Changing levels in R Shiny

shiny
r
#1

I have a field where the levels are broken down as below:

levels(demo$age)
"18 to 24 years old"    "25 to 34 years old"    "35 to 44 years old"    "45 to 54 years old"    "55 to 64 years old"    "65 to 74 years old"    "75 years old or older"

How can I change the levels to

 "Total " "18 to 24 years old" "25 plus".
#2

Check out the fct_collapse() function in {forcats}

*n.b. "Total" wouldn't be a level if it encompasses everything.

library(forcats)
fct_count(gss_cat$partyid)
#> # A tibble: 10 x 2
#>    f                      n
#>    <fct>              <int>
#>  1 No answer            154
#>  2 Don't know             1
#>  3 Other party          393
#>  4 Strong republican   2314
#>  5 Not str republican  3032
#>  6 Ind,near rep        1791
#>  7 Independent         4119
#>  8 Ind,near dem        2499
#>  9 Not str democrat    3690
#> 10 Strong democrat     3490
partyid2 <- fct_collapse(gss_cat$partyid,
  missing = c("No answer", "Don't know"),
  other = "Other party",
  rep = c("Strong republican", "Not str republican"),
  ind = c("Ind,near rep", "Independent", "Ind,near dem"),
  dem = c("Not str democrat", "Strong democrat")
)
fct_count(partyid2)
#> # A tibble: 5 x 2
#>   f           n
#>   <fct>   <int>
#> 1 missing   155
#> 2 other     393
#> 3 rep      5346
#> 4 ind      8409
#> 5 dem      7180

Created on 2018-05-29 by the reprex package (v0.2.0).

#4

So I am doing this using reactive in Shiny.

gender_levels <- reactive({
  fct_collapse(with_demo_vars()$gender,
                         Total = c("Male", "Female"),
                         Male = c("Male"),
                         Female = c("Female"))
  print(gender_levels)
})

  output$choose_gender <- renderUI({
    checkboxGroupInput(
      "selected_gender",
      "Gender",
      choices = fct_count(gender_levels),
      selected = fct_count(gender_levels)
    )
  })

I get the following error :

f must be a factor (or character vector).

#5

Hmm, as mentioned, I don't think Total is actually a case of fct_collapse(), but there are probably elements of what's going on that are related to Shiny. So, I'd recommend you move this over to the #shiny category so you can get more knowledgeable help!