Apply a function on certain rows of a dataframe

[RBM]

Hi, I am trying to apply linear interpolation on a column EVI of a dataframe df. However, the column EVI has three distinct year classes (2015, 2016 and 2017). The code below (na.approx) applies to the whole column. I want to apply the linear interpolation function on different years (2015, 2016, 2017) for a single column.

# This function applies the linear interpolation on the whole column
df$EVI<- na.approx(df$EVI,  na.rm= FALSE, maxgp =Inf, rule =2)
#I want apply the function on different years for 2015, 2016 and 2017

[nirgrahamuk]

To apply a function to a group of rows within a data.frame I would use dplyr group_modify

Apply a function to each group — group_map