条件付きでデータフレームに行を挿入する

Question

の後に新しい行を挿入するにはmtcarsデータセットでhpが110を超え、hpで車を維持する< = 110？

library(tidyverse) 
data(mtcars) 

I'veは、次のことを試みたが、success--

mtcars %>% modify_if(.p = .$hp>110,.f = add_row(.after=1)) #noe equal lengths 
mtcars %>% filter(hp>110) %>% add_row(.after=1) #only gives an extra row for the first row meeting condition 
mtcars %>% rownames_to_column() %>% 
    group_by(rowname) %>% modify_if(.p=.$hp>110,.f=add_row(.after=1)) #not egual length 

せずに、次の - purrr-を使用して動作するようです：

foo <- function(df){ 
    if (df$hp>110) {df<-add_row(.data=df,.after=1)} 
    df 
} 

mtcars %>% rownames_to_column(var = "make") %>% nest(-make) %>% 
    mutate(new=map(data,~ foo(.x))) %>% select (-data) %>% unnest(new) 

add_row_ifと呼ばれる任意の機能？

Answer 1

これは、乱数（あなたのフィルタに一致する各行の下にrunif(length(.))の新しい行を挿入：

mtcars %>% filter(hp > 110) %>% 
    group_by(row_number()) %>% 
    do ( 
    rbind(., runif(length(.))) 
    ) %>% 
    ungroup() 

# # A tibble: 36 × 12 
# mpg  cyl  disp   hp  drat   wt  qsec  vs 
# <dbl>  <dbl>  <dbl>  <dbl>  <dbl>  <dbl>  <dbl>  <dbl> 
# 1 18.70000000 8.0000000 360.0000000 175.0000000 3.15000000 3.440000000 17.02000000 0.0000000 
# 2 0.98189043 0.5940565 0.7401747 0.7300069 0.73460416 0.102802673 0.06632293 0.3771534 
# 3 14.30000000 8.0000000 360.0000000 245.0000000 3.21000000 3.570000000 15.84000000 0.0000000 
# 4 0.02192815 0.4811006 0.6456729 0.2900382 0.69145964 0.741733891 0.34932004 0.1356568 
# 5 19.20000000 6.0000000 167.6000000 123.0000000 3.92000000 3.440000000 18.30000000 1.0000000 
# 6 0.95568849 0.6532453 0.8744450 0.3346875 0.66217223 0.776532606 0.24731722 0.9633778 
# 7 17.80000000 6.0000000 167.6000000 123.0000000 3.92000000 3.440000000 18.90000000 1.0000000 
# 8 0.43592634 0.6036127 0.3185138 0.1035780 0.48505561 0.007380369 0.24154177 0.4978268 
# 9 16.40000000 8.0000000 275.8000000 180.0000000 3.07000000 4.070000000 17.40000000 0.0000000 
# 10 0.10970496 0.9063285 0.4659718 0.2793090 0.04670105 0.337342230 0.85691425 0.2758889 
# # ... with 26 more rows, and 4 more variables: am <dbl>, gear <dbl>, carb <dbl>, 
# # `row_number()` <dbl>