How to determine the row that have min and max values in an R data frame column?

R ProgrammingServer Side ProgrammingProgramming

In data analysis, often we require to determine the minimum and maximum values because these values help us to understand the limits of a column or variable under consideration. This can be done by using which.max for maximum and which.min for minimum with single square brackets to extract the rows.

Example

Consider the below data frame −

 Live Demo

x1<-LETTERS[1:20]
x2<-rpois(20,5)
x3<-rexp(20,2)
x4<-rexp(20,5)
df1<-data.frame(x1,x2,x3,x4)
df1

Output

 x1 x2     x3        x4
1 A 7 0.56888750 0.10767756
2 B 7 0.04138254 0.01507087
3 C 3 0.82145385 0.02568754
4 D 4 0.07945021 0.51976803
5 E 7 0.73930797 0.41403820
6 F 7 0.05651587 0.04107620
7 G 4 0.11206284 0.55322510
8 H 3 0.33525532 0.29126855
9 I 6 0.76841536 0.55258446
10 J 2 0.96441097 0.29656683
11 K 1 0.10678610 0.05482085
12 L 14 0.28394648 0.15006675
13 M 1 0.96666190 0.21007950
14 N 4 1.80137393 0.07231502
15 O 8 0.65978932 0.19218883
16 P 6 0.46538207 0.13262744
17 Q 4 0.15772843 0.31552748
18 R 6 0.07239103 0.38449618
19 S 7 0.46414726 0.04460063
20 T 4 0.12917123 0.76904118

Determining the rows that have maximum and minimum values for a particular column −

Example

df1[which.max(df1$x2),]

Output

   x1 x2     x3       x4
12 L 14 0.2839465 0.1500667

Example

df1[which.min(df1$x2),]

Output

   x1 x2       x3       x4
11 K  1    0.1067861 0.05482085

Example

df1[which.min(df1$x3),]

Output

 x1 x2       x3       x4
2 B 7    0.04138254 0.01507087

Example

df1[which.min(df1$x4),]

Output

  x1 x2     x3        x4
2 B  7  0.04138254 0.01507087

Let’s have a look at another example −

Example

 Live Demo

y1<-sample(1:100,20)
y2<-sample(1:10,20,replace=TRUE)
y3<-sample(20:100,20,replace=TRUE)
y4<-sample(50:100,20,replace=TRUE)
y5<-rpois(20,15)
df2<-data.frame(y1,y2,y3,y4,y5)
df2

Output

   y1 y2 y3 y4 y5
1  20 10 64 81 19
2 100 5  29 61 20
3  93 4  61 68 14
4  84 2  43 76 17
5  94 1  37 81 6
6  41 1 100 76 19
7  8  5 78 79 19
8  39 2 28 53 19
9  74 2 72 73 12
10 81 3 30 77 15
11 63 5 27 52 21
12 82 6 24 95 19
13 11 10 48 89 12
14 2  3 69 55 13
15 19 3 89 85 18
16 77 1 93 91 18
17 13 8 45 97 13
18 31 1 92 79 9
19 30 4 30 97 15
20 22 8 25 59 19

Example

df2[which.min(df2$y1),]

Output

y1 y2 y3 y4 y5
14 2 3 69 55 13

Example

df2[which.min(df2$y2),]

Output

  y1 y2 y3 y4 y5
5 94 1  37 81 6

Example

df2[which.max(df2$y2),]

Output

  y1 y2 y3 y4 y5
1 20 10 64 81 19

Example

df2[which.min(df2$y3),]

Output

   y1 y2 y3 y4 y5
12 82  6 24 95 19

Example

df2[which.min(df2$y5),]

Output

  y1 y2 y3 y4 y5
5 94 1  37 81 6
raja
Published on 09-Sep-2020 08:22:05
Advertisements