How to Use the intersect() Function in R

To fnd common elements between two vector or object, you can use intersect() function in R.

The following method shows how you can do it with syntax.

Method: Use intersect() Function

intersect(object1,object2)

Let’s understood this syntax using example:

Use intersect() Function For Vectors

Let’s create two vectors and apply intersect() function on them:

# Define vector
Temp1=c(77,"A",89,78,"C",84,81,74,"B")
Temp2=c(77,85,"A",77,78,"D",75,74,"B")

# Use intersect function
i <- intersect(Temp1,Temp2)

# Show common values
print(i)

Output:

[1] "77" "A"  "78" "74" "B" 

As in output we get five commmon elements from both vectors.

Use intersect() Function For Data Frame

Now apply intersect() function from dplyr package on two different data frames and see how its works:

# Load library
library(dplyr)

# Create data frame
df1 <- data.frame(Machine_name=c("A","C","D","F","B","H"),
                  Temp=c(77,89,78,84,81,73))

df2 <- data.frame(Machine_name=c("B","C","E","F","G","I"),
                  Temp=c(81,89,77,84,75,74))

# Find intesection between two data frames
dplyr::intersect(df1,df2)

Output:

 Machine_name Temp
1            C   89
2            F   84
3            B   81

As we can see in the output 3 common rows get from both data frames.