I need a function similar to expand.grid in R, which takes a set of vectors and returns their Cartesian product . Is there existing art? My first cut is function expandgrid(vecs) expd = [] # vector of expanded vectors inner, outer = 1, prod(length, vecs) for v in vecs lv = le…

Thanks, I would have never found the solution myself :sweat_smile:

A trivial package (with unit tests etc) could solve this very quickly.

Well, it seems with my use case there is a collect or so missing somwhere: I am trying to apply a function (datagrid) to each column of a dataframe, then create a new dataframe which would be the “product” (all combinations) of the previous values. using DataFrames # Function to get a linear rang…

For me, it is not clear, what the desired result of collect(Base.product(X)) should be. With your code it is julia> collect(Base.product(X)) 2-element Array{Tuple{Array{Float64,1}},1}: ([0.0, 1.0, 2.0],) ([10.0, 15.0, 20.0],) But maybe it should be julia> X=collect(Base.product(X...)) 3×3 Ar…

perfect guess, that was what I wanted, thanks a lot :slight_smile:

I forgot the vec in julia> X=vec(collect(Base.product(X...))) 9-element Array{Tuple{Float64,Float64},1}: (0.0, 10.0) (1.0, 10.0) (2.0, 10.0) (0.0, 15.0) (1.0, 15.0) (2.0, 15.0) (0.0, 20.0) (1.0, 20.0) (2.0, 20.0) but end result is the same: julia> X=DataFrame(collect.(collect(zip(X...)))…

It seems that the last step doesn’t work when they are three variables (it takes forever to compute): These first steps work as expected: df = DataFrame(y=[1,3], x=[5,6], z=[8,9]) grid = colwise(x -> datagrid(x, n=3), df) grid = vec(collect(Base.product(grid...))) 27-element Array{Tuple{Float64,F…

This seems to be a bug in julia 1.0.0 julia 0.6.4: julia> a=1:30 1:30 julia> collect(zip(a...)) 0-dimensional Array{NTuple{30,Int64},0}: (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30) julia 1.0.0: julia> a=1:30 1:30 julia> zip(a.…

This is how it works nicely in julia 0.6.4: using DataFrames function datagrid(X::Array{<:Number}; n::Int=10, kwargs...) collect(range(minimum(X), (maximum(X)-minimum(X))/(n-1), n)) end df = DataFrame(y=[1,3], x=[5,6], z=[8,9]) grid = getindex.(colwise(x -> datagrid(Array(x), n=3), df),1) gri…

This is a julia 1.0.0 suggestion avoiding zip, only the last line changed: using DataFrames # Function to get a linear range function datagrid(X::Vector{<:Number}; n::Int=10, kwargs...) X = collect(range(minimum(X), stop=maximum(X), length=n)) end df = DataFrame(y=[1,3], x=[5,6], z=[8,9]) gri…

Function like expand.grid in R

General Usage

pdeffebach July 10, 2023, 6:32pm 23

There a DataFrames.jl function added in the past year called allcombinations. See here

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Function like expand.grid in R

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