Setting Options

TidierData.jl comes with two settings that make it easier to understand the transformations that are being applied to a data frame and to troubleshoot errors. These settings are log and code. The log setting outputs information about the data frame after each transformation, including the number of missing values and the number of unique values in each column. The code setting outputs the code that is being executed by the TidierData.jl macros. By default, both settings are set to false. This page will review the log and code settings using the movies dataset.

We recommend setting the log setting to true in general, and especially when you are first learning TidierData.jl. This will help you understand how the data frame is being transformed at each step. The code setting is useful for debugging errors in TidierData.jl chains.

using TidierData
using RDatasets

movies = dataset("ggplot2", "movies");

log

Logging is set to false by default but can enabled as follows:

TidierData_set("log", true)

true

When enabled, each macro called will show information about its transformation of the data. Logging can be especially useful to catch silent bugs (those that do not result in an error).

When column values are changed, it will report the number new missing values, the percentage of missing values, and the number of unique values.

@chain movies begin
    @filter(Year > 2000)
    @mutate(Budget_cat = case_when(Budget > 18000 => "high",
                                   Budget > 2000  => "medium",
                                   Budget > 100 => "low",
                                    true => missing))
    @filter(!ismissing(Budget))
    @group_by(Year, Budget_cat)
    @summarize(Avg_Budget = mean(Budget), n = n())
    @ungroup
    @arrange(n)
end

20×4 DataFrame

Row	Year	Budget_cat	Avg_Budget	n
	Int32	String?	Float64	Int64
1	2005	low	2000.0	1
2	2002	missing	0.0	2
3	2001	missing	0.0	3
4	2001	low	1425.0	4
5	2005	missing	0.0	4
6	2004	missing	0.0	4
7	2002	low	1500.0	7
8	2003	missing	0.0	7
9	2005	medium	8249.94	16
10	2003	low	1443.48	23
11	2001	medium	9580.0	25
12	2004	low	1308.0	25
13	2002	medium	7815.33	30
14	2003	medium	8027.28	67
15	2005	high	2.0684e7	82
16	2004	medium	7946.05	91
17	2003	high	2.14431e7	276
18	2001	high	2.13646e7	289
19	2002	high	2.17604e7	320
20	2004	high	1.88698e7	336

Logging can also be disabled.

TidierData_set("log", false) # disable logging

false

code

Code printing is set to false by default. Enabling this setting prints the underlying DataFrames.jl code created by TidierData.jl macros. It can be useful for debugging, especially for users who understand DataFrames.jl syntax, or for filing bug reports.

TidierData_set("code", true) # enable macro code output

@chain movies begin
    @select(Title, Year, Budget)
    @slice_sample(n = 10)
end

10×3 DataFrame

Row	Title	Year	Budget
	String	Int32	Int32?
1	Dangerous Davies - The Last Detective	1981	missing
2	Stolen Heart	1998	missing
3	Don't Go Breaking My Heart	1999	missing
4	Transylvania 6-5000	1985	missing
5	Amores	1998	missing
6	Polar	1984	missing
7	Angel	1966	missing
8	Criminally Insane 2	1987	missing
9	Burgtheater	1936	missing
10	Carrier, The	1988	missing

Code printing can also be disabled.

TidierData_set("code", false) # disable macro code output

false

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