What is the problem with this Julia code?

General Usage
1

I wrote a function that plots several boxplots, ordered by the orders of a factor (categorical variable). It works, but VSCode keeps telling me there is a problem in one of the lines. Would someone know the reason?

Here is the code:


using DataFrames, StatsPlots

varnames = ["Winter", "Spring", "Summer", "Fall"]
df = DataFrame(
    :variable => categorical(repeat(varnames, 20), levels = varnames),
    :value => rand(80)
)

function boxplot_ordered(
    df::DataFrame;
    variable_col::Symbol = :variable,
    value_col::Symbol = :value,
    plotsize::Tuple{Int64,Int64} = (800, 600) # ctrl_parms.PlotSize
)
    msg = "`variable_col` is not a column name of `df`"
    @assert string(variable_col) in names(df) msg

    msg = "`value_col` is not a column name of `df`"
    @assert string(value_col) in names(df) msg

    msg = "Column `variable_col` of `df` is not categorical"
    @assert typeof(df[!, variable_col]) <: CategoricalVector msg

    variable_order = string.(levels(df[!, variable_col]))
    v = collect(1:length(variable_order))
    d = Dict(zip(variable_order, v))
    
    dfc = select(
        df,
        variable_col => ByRow(x -> d[x]) => :Order,
        variable_col => (x -> (string.(x))) => variable_col,
        value_col,
    )

    p = boxplot(
        dfc.Order,
        dfc[!, value_col],
        legend = false,
        size = plotsize
    )
    plot!(xticks = (v, variable_order)) # THIS IS THE LINE FLAGGED AS A PROBLEM

    display(p)

    return p
end # boxplot_ordered

boxplot_ordered(df)
2

I would suggest posting the error message.

1 Like
3

I would assume the problem is with VSCode, and not the Julia code.

4

Works for me. I didn’t get any error when running your code.

5

I think it is not an error but problem with VS code in windows. I also get the blue underline in windows but it is not present on Linux machine.
plot_warning

6

I ran it on VSCode in Windows and had no issue.

7

I don’t get an error when running the code. It is just that VSCode inserts that line in the list of Problems, with the message “Possible method call error.”

8

The message is "“Possible method call error.” It is not an error message, The function runs with no problems. It is a Problem flagged by VSCode.

9

Probably related to this issue:

https://github.com/julia-vscode/julia-vscode/issues/1576

It is the problem with linter. So the code will work.