I am trying to write a function that will run only on the logical columns in my dataframe. To do this I am first trying to generate a list of the column numbers in my data frame which are classified as "logical."
For dataframe m here are how my data is classified:
str(m)
'data.frame': 169 obs. of 42 variables:
$ Municipality : chr "Andover" "Ansonia" "Ashford" "Avon" ...
$ Webpage_Link : chr "http://andoverconnecticut.org/services-government/building-zoning/" "http://www.cityofansonia.com/content/2524/2582/default.aspx" "http://www.ashfordtownhall.org/government/land-use/building-department/" "http://www.avonct.gov/building-department" ...
$ Webpage_LastUpdate : chr NA NA NA NA ...
$ Researcher : chr "DM" "DM" "LG" "LG" ...
$ Collection.Date : chr "11/4/15" "11/4/15" "1/26/16" "1/26/16" ...
$ Complete : logi TRUE TRUE TRUE TRUE TRUE TRUE ...
$ Application_BuildPermit : logi TRUE FALSE TRUE TRUE FALSE TRUE ...
$ Application_SolarPermt : logi FALSE FALSE TRUE TRUE FALSE FALSE ...
$ Contact_Name : logi TRUE TRUE TRUE TRUE TRUE FALSE ...
$ Contact_Address : logi TRUE TRUE TRUE TRUE TRUE TRUE ...
(df <- data.frame(a = 1:3, b = letters[1:3], c = TRUE))
# a b c
# 1 1 a TRUE
# 2 2 b TRUE
# 3 3 c TRUE
sapply(df, is.logical)
# a b c
# FALSE FALSE TRUE
If you really need a vector of numbers then you may additionally apply which:
which(sapply(df, is.logical))
# c
# 3