 # Why don't I get a matrix of colors instead of a vector?

When I create four random colors, a and b show up as a row of four swatches
But when I try to create a matrix [a;b], figuring four over and under, all I get is a vector row of eight swatches

What am I doing wrong?

a = [RGB(rand(),rand(),rand()) for x in 1:4]
b = [RGB(rand(),rand(),rand()) for x in 1:4]

[a;b] Interesting. I also want to know, but I would’ve done

``````vcat(a, b)
``````

or

``````transpose([a b])
``````

or

``````reshape([a;b], 2, :)
``````

This is a matter of Julia’s design, not a problem of colors.

``````julia> a = [1, 2, 3, 4]; b = [5, 6, 7, 8];

julia> [a; b]
8-element Vector{Int64}:
1
2
3
4
5
6
7
8
``````

However, I don’t think it is useful to arrange the color swatches vertically.

1 Like

To get a 2-row matrix from two vectors of reals one can do: `[a'; b']` for more general case you could use: `permutedims([a b])`

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Thanks. What is the apostrophe for? I haven’t seen that usage.

Check the help:

``````help?>  '
A'