Consider the following table:
julia> using RDatasets, DataFrames
julia> anscombe = dataset("datasets","anscombe")
11x8 DataFrame
| Row | X1 | X2 | X3 | X4 | Y1 | Y2 | Y3 | Y4 |
|-----|----|----|----|----|-------|------|-------|------|
| 1 | 10 | 10 | 10 | 8 | 8.04 | 9.14 | 7.46 | 6.58 |
| 2 | 8 | 8 | 8 | 8 | 6.95 | 8.14 | 6.77 | 5.76 |
| 3 | 13 | 13 | 13 | 8 | 7.58 | 8.74 | 12.74 | 7.71 |
| 4 | 9 | 9 | 9 | 8 | 8.81 | 8.77 | 7.11 | 8.84 |
| 5 | 11 | 11 | 11 | 8 | 8.33 | 9.26 | 7.81 | 8.47 |
| 6 | 14 | 14 | 14 | 8 | 9.96 | 8.1 | 8.84 | 7.04 |
| 7 | 6 | 6 | 6 | 8 | 7.24 | 6.13 | 6.08 | 5.25 |
| 8 | 4 | 4 | 4 | 19 | 4.26 | 3.1 | 5.39 | 12.5 |
| 9 | 12 | 12 | 12 | 8 | 10.84 | 9.13 | 8.15 | 5.56 |
| 10 | 7 | 7 | 7 | 8 | 4.82 | 7.26 | 6.42 | 7.91 |
| 11 | 5 | 5 | 5 | 8 | 5.68 | 4.74 | 5.73 | 6.89 |
I have defined a function as follows:
julia> f1(df, matchval, matchfield, qfields...) = isempty(qfields)
WARNING: Method definition f1(Any, Any, Any, Any...) in module Main at REPL[314]:1 overwritten at REPL[317]:1.
f1 (generic function with 3 methods)
Now below is the problem
julia> f1(anscombe, 11, "X1")
ERROR: KeyError: key :field not found
in getindex at ./dict.jl:697 [inlined]
in getindex(::DataFrames.Index, ::Symbol) at /home/arghya/.julia/v0.5/DataFrames/src/other/index.jl:114
in getindex at /home/arghya/.julia/v0.5/DataFrames/src/dataframe/dataframe.jl:228 [inlined]
in f1(::DataFrames.DataFrame, ::Int64, ::String) at ./REPL[249]:2
Where am I doing wrong? FYI I'm using Julia Version 0.5.2. How to overcome this problem? Thanks in advance!
There is nothing wrong with your code - try running just what you've posted in a fresh session. Possibly you've defined another f1 method before. If you come from R, you may assume that this is overwritten by f1(df, matchval, matchfield, qfields...) = isempty(qfields), while in fact you're just defining a new method for the f1 function. The error is probably thrown by a 3-argument version you've defined earlier. Look at https://docs.julialang.org/en/stable/manual/methods/