How would one round up to the nearest whole value only IF the value meets criteria, and keeping the-CodePudding

How would one round up to the nearest whole value only IF the values after decimal is >= 0.75? And keeping the original column within the df.

df1 <- data.frame(names = c("A","B","C","D","E"),
                  years_in_rank = c(3.15, 4.25, 5.75, 6.90, NA))

# Desired Outcome

names  years_in_rank   final_yir
A      3.15            3.15
B      4.25            4.25
C      5.75            6.00
D      6.90            7.00
E      NA              NA

**This was the very long approach, that prompted the question. ** (Im going to guess some beautiful use of case when can be used instead.)

library(tidyr)
# Transforming years in rank to separate columns
df1 %>%  separate(years_in_rank, into = c("years_whole", "years_deci"),
remove = FALSE)

#Transform years_in_deci back to decimal
df1$years_deci <- as.numeric(as.character(df1$years_deci))/100

# Rounding rules
df1 <- df1 %>% 
  mutate(years_deci_rounded = if_else(years_deci >= 0.75, round(years_deci, 0), years_deci),.after = years_deci)

#Final desired output column
df1 <- df1 %>% 
  mutate(final_yir = if_else(years_deci_rounded == 1, as.numeric(years_whole)   years_deci_rounded, years_in_rank),.after = years_deci_rounded)

CodePudding user response：

One approach using floor

cbind(df1, final_yir = 
  ifelse(df1$years_in_rank - floor(df1$years_in_rank) >= 0.75, 
         ceiling(df1$years_in_rank), df1$years_in_rank))
  names years_in_rank final_yir
1     A          3.15      3.15
2     B          4.25      4.25
3     C          5.75      6.00
4     D          6.90      7.00
5     E            NA        NA

With dplyr

library(dplyr)

df1 %>% 
  mutate(final_yir = ifelse(years_in_rank - floor(years_in_rank) >= 0.75, 
                            ceiling(years_in_rank), years_in_rank))
  names years_in_rank final_yir
1     A          3.15      3.15
2     B          4.25      4.25
3     C          5.75      6.00
4     D          6.90      7.00
5     E            NA        NA

CodePudding user response：

df %>%
  mutate(rounded = if_else(
    round(years_in_rank) == ceiling(years_in_rank),
    ceiling(years_in_rank),
    years_in_rank
  ))

# A tibble: 5 × 3
  names years_in_rank rounded
  <chr>         <dbl>   <dbl>
1 A              3.15    3.15
2 B              4.25    4.25
3 C              5.75    6   
4 D              6.9     7   
5 E             NA      NA

CodePudding user response：

You could use the mod 1 trick:

library(dplyr)

df1 %>% 
  mutate(final_year = ifelse((years_in_rank - years_in_rank %/% 1) >= 0.75,
                              ceiling(years_in_rank), 
                              years_in_rank))

This returns

  names years_in_rank final_year
1     A          3.15       3.15
2     B          4.25       4.25
3     C          5.75       6.00
4     D          6.90       7.00
5     E            NA         NA