CODEWITHSUNDEEP
julia
Henrik Renlund
Henrik Renlund

Reputation: 329

DataArrays in Julia

I'm trying out Julia and the DataArray package. I want to initialize, with zeros, a data array of a size given by an integer stored in a variable 'n'. However, I get an error message "ERROR: n not defined" (even though it clearly seems to be).

The following is a small example:

using DataArrays
n = 8
@data(zeros(Float64,n))

which for me produces the above error message. (Note that

using DataArrays
@data(zeros(Float64,8))

does work.)

Any ideas?

Upvotes: 2

Views: 1166

Answers (1)

Michael Fox
Michael Fox

Reputation: 3642

n = 8
float64(DataArray(zeros(Float64 ,n)))

Will get you where you're going. The @data macro kind of sucks and the only use I can think for it is when writing tests if you want to say something like

x = @data([1,2,3,NA])

Normally the list constructor will crap on you. However this does also work:

x = float64(DataArray(Any[1,2,3,NA]))

So, I don't know. Stay away from that @data macro. Macros in general have a hard time seeing your local variables or functions and variables from other Modules. It's a problem that can clearly be worked around since @show mostly works, but many macros have this and other problems. Macros in general are kind of suspect.

Upvotes: 1

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