CODEWITHSUNDEEP
dataframejuliasubset
spiral01
spiral01

Reputation: 545

Julia: invalid assignment location when creating function to subset dataframe

I am creating a function in Julia. It takes a dataframe (called window) and two strings (A and B) as inputs and subsets it using the variables given:

function calcs(window, A, B):
     fAB=size(window[(window[:ref].==A).&(window[:alt].==B),:])[1]
end

But I get the error:

syntax: invalid assignment location ":fAB"

Stacktrace:
 [1] include_string(::String, ::String) at ./loading.jl:522

I have tried running the code outside of a function (having pre-assigned the variables A="T" and B="C" like so:

fAB=size(window[(window[:ref].==A).&(window[:alt].==B),:])[1]

and this runs fine. I am new to Julia but cannot find an answer to this question. Can anyone help?

Upvotes: 1

Views: 1479

Answers (1)

Bogumił Kamiński
Bogumił Kamiński

Reputation: 69819

Seems you come from Python world. In Julia you do not need to add : in function definition. This will go through fine:

function calcs(window, A, B)
     fAB=size(window[(window[:ref].==A).&(window[:alt].==B),:])[1]
end

When Julia encounters : in the first line of function definition it continues parsing the expression in the following line producing :fAB symbol.

EDIT: In Julia 0.7 this problem is detected by the parser. This is the result of copy-pasting your original code to REPL:

julia> function calcs(window, A, B):
            fAB=size(window[(window[:ref].==A).&(window[:alt].==B),:])[1]
ERROR: syntax: space not allowed after ":" used for quoting

julia> end
ERROR: syntax: unexpected "end"

Upvotes: 4

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