How to sort alphabetically rows of a data frame?

EnginO picture EnginO · Feb 25, 2015 · Viewed 12.2k times · Source

I am tring to sort c alphabetically if x[i]== x[i+1]. I used order() function but it changes the x column as well. I want to order the entire row:

 best <- function(state){
 HospitalName<-vector()
 StateName<-vector()
 HeartAttack<-vector()

  k<-1

  outcome<-read.csv("outcome-of-care-measures.csv",colClasses= "character")

 temp<-(outcome[,c(2,7,11,17,23)])

for (i in 1:nrow(temp)){
 if(identical(state,temp[i,2])==TRUE){
    HospitalName[k]<-temp[i,1]
    StateName[k]<-temp[i,2]
    HeartAttack[k]<-as.numeric(temp[i,4])
    k<-k+1
     }}
    frame<-data.frame(cbind(HospitalName,StateName,HeartAttack))


  library(dplyr)
  frame %>%
  group_by(as.numeric(as.character(frame[,3]))) %>%
  arrange(frame[,1])
    }

  Output:
                               HospitalName StateName HeartAttack
 1              FORT DUNCAN MEDICAL CENTER        TX         8.1
 2         TOMBALL REGIONAL MEDICAL CENTER        TX         8.5
 3        CYPRESS FAIRBANKS MEDICAL CENTER        TX         8.7
 4                  DETAR HOSPITAL NAVARRO        TX         8.7
 5                  METHODIST HOSPITAL,THE        TX         8.8
 6         MISSION REGIONAL MEDICAL CENTER        TX         8.8
 7  BAYLOR ALL SAINTS MEDICAL CENTER AT FW        TX         8.9
 8       SCOTT & WHITE HOSPITAL-ROUND ROCK        TX         8.9
 9         THE HEART HOSPITAL BAYLOR PLANO        TX           9
 10    UT SOUTHWESTERN UNIVERSITY HOSPITAL        TX           9
..                                    ...       ...         ...
Variables not shown: as.numeric(as.character(frame[, 3])) (dbl)

Output does not contain the HeartAttack Column and I do not understand why?

Answer

LyzandeR picture LyzandeR · Feb 25, 2015

One solution with dplyr:

library(dplyr)
df %>%
  group_by(x) %>%
  arrange(c)

Or as @Akrun mentions in the comments below just

df %>%
  arrange(x,c)

if you are not interested in grouping. Depends on what you want.

Output:

Source: local data frame [5 x 2]
Groups: x

  x c
1 2 A
2 2 D
3 3 B
4 3 C
5 5 E

There is another solution in base R but it will only work if your x column is ordered as is, or if you don't mind changing the order it has:

> df[order(df$x, df$c), , drop = FALSE]
  x c
2 2 A
1 2 D
4 3 B
3 3 C
5 5 E