myd = DataFrame(a = 1:3, b = ["aba","saba","daba" ]) Now trying to find the position of :b elements in certain vector and make a new column out of it: myd = transform(myd, :b => (v -> findfirst(x -> x==v, ["saba","daba","myy","aba","oba"])) => :sort_order) I end up with column of nothing.

It’s because your function is wrongly specified: You check if x == v where x is an element in the vector v. You could do v2 = ["saba","daba","myy","aba","oba"] transform(myd, :b => v -> [findfirst(isequal(i), v) for i in v2]) To be more efficient, you should probably create a Dict{String, Int} t…

Finding the position in array

New to Julia

rafael.guerra February 14, 2022, 1:31pm 3

@Mastomaki, what result do you expect?

Topic		Replies	Views
Find position of Array elements in another Array General Usage indexing , arrays	16	3748	February 1, 2023
Find position on list (fast) General Usage	13	847	November 22, 2021
Using findfirst with for multiple values and columns in a Dataframe? New to Julia dataframes	21	714	March 24, 2024
Findall/Findfirst across multiple columns in dataframe New to Julia	15	2474	March 26, 2021
Compare dataframes regardless of column order General Usage dataframes	8	276	February 4, 2025

Finding the position in array

Related topics