Check if a dataframe column contains decimal values

Question

Sample Dataframe

df<- data.frame(column1=c("row1", "row2", "row3", "row4", "row5", "row6"), column2=c(1,3,4.3,5,6.5,7.8))

check if df$column2 contains decimals. The result should be a TRUE or FALSE

Answer 1

Try this:

round(df$column2) != df$column2

Since you cannot create a column of internals and doubles, we improperly assume that if the decimal part is 0, then the number is integer.

If you are interested in knowing if the column contains at least one decimal use

any(round(df$column2) != df$column2)

If you are interested in knowing if all the column values ​​are decimal use

all(round(df$column2) != df$column2)

Answer 2

Use the modulus operator.

x%%1==0 will check if the modulus (x mod 1) is 0

x%%1!=0 will check if the modulus (x mod 1) is not 0, which means its value has decimals

This will give you elementwise results:

> df$column2%%1!=0
[1] FALSE FALSE  TRUE FALSE  TRUE  TRUE

for an aggregate on the whole column, call

any(df$column2%%1!=0)

[1] TRUE