How to add vectors to the columns of some array in Julia?

dataframe, julia

Solution

If you know how many rows you have in your final Array, you can do it using `hcat`:

# The number of lines of your final array
numrows = 3

# Create an empty array of the same type that you want, with 3 rows and 0 columns:
a = Array(Int, numrows, 0)

# Concatenate 3x1 arrays in your empty array:
for i in 1:numrows
    b = [i, i+1, i*2] # Create the array you want to concatenate with a
    a = hcat(a, b)
end

Notice that, here you know that the arrays `b` have elements of the type `Int`. Therefore we can create the array `a` that have elements of the same type.

Problem

I know that, with package `DataFrames`, it is possible by doing simply ``` julia> df = DataFrame(); julia> for i in 1:3 df[i] = [i, i+1, i*2] end julia> df 3x3 DataFrame |-------|----|----|----| | Row # | x1 | x2 | x3 | | 1 | 1 | 2 | 3 | | 2 | 2 | 3 | 4 | | 3 | 2 | 4 | 6 | ``` ... but are there any means to do the same on an empty `Array{Int64,2}` ?

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