My dataframe looks like this:
head(temp$HName)
[1] "UNIVERSITY OF TEXAS HEALTH SCIENCE CENTER AT TYLER"
[2] "METHODIST HOSPITAL,THE"
[3] "TOMBALL REGIONAL MEDICAL CENTER"
[4] "METHODIST SUGAR LAND HOSPITAL"
[5] "GULF COAST MEDICAL CENTER"
[6] "VHS HARLINGEN HOSPITAL COMPANY LLC"
head(temp$Rate)
[1] 7.3 8.3 8.7 8.7 8.8 8.9
76 Levels: 7.3 8.3 8.7 8.8 8.9 9 9.1 9.2 9.3 9.4 9.5 9.6 ... 17.1
> head(temp$Rank)
[1] NA NA NA NA NA NA
The temp$Rate is sorted. I am trying to write a function assignRank which gives me a new column temp$Rank which has values as 1, 2, 3, 3, 4, 5
My code is as below:
tapply(temp$Rank,temp$Rate, assignRank)
where :
assignRank<- function(r=1){
temp$Rank <- r
r <- r + 1
return(r)
}
I get following error when running tapply
tapply(temp$Rank,temp$Rate, assignRank)
Show Traceback
Rerun with Debug
Error in `$<-.data.frame`(`*tmp*`, "Rank", value = c(NA, NA)) :
replacement has 2 rows, data has 301
Please advise where I am going wrong?
I use data.table for stuff like this, because both sorting and ranking are very efficient/simple syntax
library(data.table)
setkey(setDT(temp), Rate) # This will sort your data set by Rate in case it's not yet sorted
temp[, Rank := .GRP, by = Rate]
temp
# HName Rate Rank
# 1: UNIVERSITY OF TEXAS HEALTH SCIENCE CENTER AT TYLER 7.3 1
# 2: METHODIST HOSPITAL,THE 8.3 2
# 3: TOMBALL REGIONAL MEDICAL CENTER 8.7 3
# 4: METHODIST SUGAR LAND HOSPITAL 8.7 3
# 5: GULF COAST MEDICAL CENTER 8.8 4
# 6: VHS HARLINGEN HOSPITAL COMPANY LLC 8.9 5
Or you could easily do the same using base R (assuming your data is sorted by Rank) just do
as.numeric(factor(temp$Rate))
## [1] 1 2 3 3 4 5
Or could also use dense_rank function from dplyr package (which will not require sorting the data set)
library(dplyr)
temp %>%
mutate(Rank = dense_rank(Rate))
# HName Rate Rank
# 1 UNIVERSITY OF TEXAS HEALTH SCIENCE CENTER AT TYLER 7.3 1
# 2 METHODIST HOSPITAL,THE 8.3 2
# 3 TOMBALL REGIONAL MEDICAL CENTER 8.7 3
# 4 METHODIST SUGAR LAND HOSPITAL 8.7 3
# 5 GULF COAST MEDICAL CENTER 8.8 4
# 6 VHS HARLINGEN HOSPITAL COMPANY LLC 8.9 5