append a list from a for loop

[ntpelly]

I would like to take the output of this loop and append it in a dataframe. Any suggestion would be helpful

[pieterjanvc]

Hi there,

Looking at the function it is not clear what you are trying to do here, but chances are you don't even need a loop with IF statement if you just want to extract or rearrange data...

Next time try to generate a reprex instead of using a screenshot. A reprex consists of the minimal code and data needed to recreate the issue/question you're having. You can find instructions how to build and share one here:

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.…

That said, here are two generic examples of appending things to a data frame, the first one just using base R, the other one using tidyverse functions.

#Base R
myData = data.frame(
  a = character(),
  b = numeric()
)

for(i in 1:10){
  if(i %% 2 == 0){
    myData[nrow(myData)+1,] = list(i, runif(1))
  }
}
myData
#>    a         b
#> 1  2 0.5419549
#> 2  4 0.8368228
#> 3  6 0.2262199
#> 4  8 0.1070023
#> 5 10 0.8860279

#Tidyverse mapping
library(tidyverse)

map_df(1:10, function(i){
  
  if(i %% 2 == 0){
    tibble(a = i, b = runif(1))
  }
  
})
#> # A tibble: 5 x 2
#>       a     b
#>   <int> <dbl>
#> 1     2 0.268
#> 2     4 0.865
#> 3     6 0.269
#> 4     8 0.701
#> 5    10 0.246

^{Created on 2021-05-03 by the reprex package (v2.0.0)}

Hope this helps,
PJ

[ntpelly]

Thanks, PJ. Here's a better visual. I'm trying to populate the data frame with the for loop out put. All I get when I run is the last variable in the dataframe that qualifies.

HDL_uip <- data.frame()

for(i in 1:nrow(under_income_pop)){
HDL_county <- under_income_pop[i, "county"]
L_uip <- under_income_pop[i,"Lcount"]
HD_uip <- under_income_pop[i, "HDcount"]

    if(L_uip == 0 | HD_uip == 0){
        HDL_uip <- data.frame(HDL_county, L_uip, HD_uip)
}

}

View(HDL_uip)