Schedule Append Data Frame

[atakzltn]

Hi,

I want to create a dataframe running a code every 30 seconds.

get_lokasyon() gives me a data frame. I want to query with get_lokasyon() every 30 seconds and add the results one after another but df_total gives me only last running get_lokasyon()

library(tcltk)

df_total = data.frame()
run <- function () { 
  .id <<- tcl("after", 30000, run) # after 30000 ms execute run() again
  
      df <- get_lokasyon()
    df_total <- rbind(df_total,df)
  print(df_total)
}

run()

Example result of get_lokasyon():

Operator Garaj KapiNo Saat Boylam Enlem
1 OHO AA 16:24:51 29.037663 41.12744

After 90 seconds I want:

Operator Garaj KapiNo Saat Boylam Enlem
1 OHO AA 16:24:51 29.037663 41.12744
2 OHO AA 16:25:40 29.037663 41.12744
3 OHO AA 16:26:10 29.037663 41.12744

Thank you

[pieterjanvc]

Hi,

The reason this is not working is because there is no loop in your function. If you like to get the results multiple times you need to specify a for-loop or while-loop.

The function tcl() might trigger ever x seconds, but this would not trigger the rest of the function around it again unless you are in a reactive environment like Shiny.

Here is an example how you could implement this

myData = data.frame()

for(x in 1:3){
  
  print(paste("Start round", x))
  newData = data.frame(x = x , time = Sys.time(), val = runif(1))
  myData = rbind(myData, newData)
  Sys.sleep(3)
  
}
#> [1] "Start round 1"
#> [1] "Start round 2"
#> [1] "Start round 3"

myData
#>   x                time       val
#> 1 1 2021-02-07 09:19:25 0.8187054
#> 2 2 2021-02-07 09:19:28 0.3396553
#> 3 3 2021-02-07 09:19:31 0.1789086

^{Created on 2021-02-07 by the reprex package (v1.0.0)}

In your case, do not set the timer within the function, but use the system sleep to wait before you run the next iteration.

Hope this helps,
PJ