How to sort an R data frame column without losing row names?

R ProgrammingServer Side ProgrammingProgramming

When we sort a data frame column in R, the row names are lost but we might need them. Therefore, sorting without losing row names is required and it can be done with the help of order function. For example, if we have a data frame called df that has a column x then sorting of x without losing row names can be done by using the below command −

df[order(df$x),,drop=FALSE]

Consider the below data frame −

Example

 Live Demo

x1<-rnorm(20)
x2<-rnorm(20,525,23.2)
df1<-data.frame(x1,x2)
row.names(df1)<-LETTERS[1:20]
df1

Output

      x1       x2
A   1.7337922  534.3863
B  -0.6754809  534.8879
C   0.1106191  520.2269
D   0.2270701  513.5676
E  -0.5678853  558.2216
F  -0.1885840  534.2416
G   0.2192299  552.8982
H   1.5135296  488.6875
I   0.9043322  529.6242
J   0.7014559  552.5001
K   0.2591020  514.1494
L  -1.1273898  580.5344
M  -0.1771963  516.4953
N   0.2317244  503.3607
O   0.6529487  501.4557
P  -0.9165830  496.4222
Q  -2.2928809  490.9002
R   0.7511574  519.3586
S   1.5003125  504.2702
T   1.3791592  496.9542

Sorting df1 based on x2 without losing row names −

df1[order(df1$x2),,drop=FALSE]

       x1        x2
H   1.5135296   488.6875
Q  -2.2928809   490.9002
P  -0.9165830   496.4222
T   1.3791592   496.9542
O   0.6529487   501.4557
N   0.2317244   503.3607
S   1.5003125   504.2702
D   0.2270701   513.5676
K   0.2591020   514.1494
M  -0.1771963   516.4953
R   0.7511574   519.3586
C   0.1106191   520.2269
I   0.9043322   529.6242
F  -0.1885840   534.2416
A   1.7337922   534.3863
B  -0.6754809   534.8879
J   0.7014559   552.5001
G   0.2192299   552.8982
E  -0.5678853   558.2216
L  -1.1273898   580.5344

Example

 Live Demo

y1<-rpois(20,5)
y2<-rpois(20,8)
df2<-data.frame(y1,y2)
row.names(df2)<-letters[1:20]
df2

Output

  y1  y2
a  5   7
b  5   5
c  4   6
d  7   1
e  3   8
f  7   9
g  5   9
h  2   7
i  3  14
j  12  6
k  6   9
l  12  7
m  2   11
n  5   6
o  5   11
p  3   3
q  6   10
r  3   9
s  7   8
t  6   8

Sorting df2 based on y1 without losing row names −

df2[order(df2$y1),,drop=FALSE]

Output

   y1  y2
h  2   7
m  2   11
e  3   8
i  3   14
p  3   3
r  3   9
c  4   6
a  5   7
b  5   5
g  5   9
n  5   6
o  5   11
k  6   9
q  6   10
t  6   8
d  7   1
f  7   9
s  7   8
j  12  6
l  12  7
raja
Published on 06-Feb-2021 09:00:45
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