Keep Drop and Order Arguments
the keep, drop and order keyword arguments act similarly and allow for quick selection of coefficients to keep and change. The sequence these options are applied in is keep -> drop -> order, so coefficients kept can then be reordered. There are four fundamental ways to select arguments:
- By string
- By Regex
- By index number
- By range
keep also adjusts the order of the coefficients, so specifying keep and then order would allow order to adjust the coefficients kept. drop does not change order of coefficients.
The keep, drop and order arguments use the relabeled versions of coefficients. If labels (or transform_labels) are used, then the keep, drop and order arguments should use the relabeled versions of the coefficients.
Just to setup these examples:
using RegressionTables, DataFrames, FixedEffectModels, RDatasets
df = dataset("datasets", "iris")
df[!,:SpeciesDummy] = df[!,:Species]
rr1 = reg(df, @formula(SepalLength ~ SepalWidth + fe(SpeciesDummy)))
rr2 = reg(df, @formula(SepalLength ~ SepalWidth + PetalLength + fe(SpeciesDummy)))
rr3 = reg(df, @formula(SepalLength ~ SepalWidth * PetalLength + PetalWidth + fe(SpeciesDummy)))
rr4 = reg(df, @formula(SepalWidth ~ SepalLength + PetalLength + PetalWidth + fe(SpeciesDummy)))
rr5 = reg(df, @formula(SepalLength ~ SepalWidth * PetalLength + fe(SpeciesDummy)))
rr6 = reg(df, @formula(SepalLength ~ SepalWidth + PetalLength + SpeciesDummy))By String
Selecting coefficients by string is the most straightforward. Specify arguments by exactly matching the output string (if labels are not used, these are the same as the input string). For example, starting with the original example:
regtable(rr1,rr2,rr3,rr4)
# output
------------------------------------------------------------------------
SepalLength SepalWidth
------------------------------ ----------
(1) (2) (3) (4)
------------------------------------------------------------------------
SepalWidth 0.804*** 0.432*** 0.719***
(0.106) (0.081) (0.155)
PetalLength 0.776*** 1.047*** -0.188*
(0.064) (0.143) (0.083)
PetalWidth -0.259 0.626***
(0.154) (0.123)
SepalWidth & PetalLength -0.070
(0.041)
SepalLength 0.378***
(0.066)
------------------------------------------------------------------------
SpeciesDummy Fixed Effects Yes Yes Yes Yes
------------------------------------------------------------------------
N 150 150 150 150
R2 0.726 0.863 0.870 0.635
Within-R2 0.281 0.642 0.659 0.391
------------------------------------------------------------------------To select the first two coefficients, specify keep=["SepalWidth", "PetalLength"]:
regtable(rr1,rr2,rr3,rr4; keep=["SepalWidth", "PetalLength"])
# output
------------------------------------------------------------------------
SepalLength SepalWidth
------------------------------ ----------
(1) (2) (3) (4)
------------------------------------------------------------------------
SepalWidth 0.804*** 0.432*** 0.719***
(0.106) (0.081) (0.155)
PetalLength 0.776*** 1.047*** -0.188*
(0.064) (0.143) (0.083)
------------------------------------------------------------------------
SpeciesDummy Fixed Effects Yes Yes Yes Yes
------------------------------------------------------------------------
Controls Yes Yes
------------------------------------------------------------------------
N 150 150 150 150
R2 0.726 0.863 0.870 0.635
Within-R2 0.281 0.642 0.659 0.391
------------------------------------------------------------------------Interacted coefficients are selected using the & to separate the interactions, even if the settings use a different interaction. For example, in Latex, the interaction defaults to \$times\$, but would still be selected by using &:
regtable(rr1, rr2, rr3, rr4; render=LatexTable(), keep=["SepalWidth & PetalLength"])
# output
\begin{tabular}{lrrrr}
\toprule
& \multicolumn{3}{c}{SepalLength} & \multicolumn{1}{c}{SepalWidth} \\
\cmidrule(lr){2-4} \cmidrule(lr){5-5}
& (1) & (2) & (3) & (4) \\
\midrule
SepalWidth $\times$ PetalLength & & & -0.070 & \\
& & & (0.041) & \\
\midrule
SpeciesDummy Fixed Effects & Yes & Yes & Yes & Yes \\
\midrule
Controls & Yes & Yes & Yes & Yes \\
\midrule
$N$ & 150 & 150 & 150 & 150 \\
$R^2$ & 0.726 & 0.863 & 0.870 & 0.635 \\
Within-$R^2$ & 0.281 & 0.642 & 0.659 & 0.391 \\
\bottomrule
\end{tabular}Similar to interacted coefficients, categorical coefficients are selected using a : between the name and the category.
By Regex
Regex allows the selection of multiple coefficients based on the provided information. For example, to select coefficients with "Width", specify keep=[r"Width"]:
regtable(rr1,rr2,rr3,rr4; keep=[r"Width"])
# output
------------------------------------------------------------------------
SepalLength SepalWidth
------------------------------ ----------
(1) (2) (3) (4)
------------------------------------------------------------------------
SepalWidth 0.804*** 0.432*** 0.719***
(0.106) (0.081) (0.155)
PetalWidth -0.259 0.626***
(0.154) (0.123)
SepalWidth & PetalLength -0.070
(0.041)
------------------------------------------------------------------------
SpeciesDummy Fixed Effects Yes Yes Yes Yes
------------------------------------------------------------------------
Controls Yes Yes Yes
------------------------------------------------------------------------
N 150 150 150 150
R2 0.726 0.863 0.870 0.635
Within-R2 0.281 0.642 0.659 0.391
------------------------------------------------------------------------Regex works similarly to the exact string argument, so if the coefficients are labeled then the regex needs to match the relabeled value. It also expects any interaction to be based on & and categorical variables to be :, for example:
regtable(rr5, rr6)
# output
-------------------------------------------------
SepalLength
--------------------
(1) (2)
-------------------------------------------------
SepalWidth 0.715*** 0.432***
(0.156) (0.081)
PetalLength 1.050*** 0.776***
(0.144) (0.064)
SepalWidth & PetalLength -0.085*
(0.040)
(Intercept) 2.390***
(0.262)
SpeciesDummy: versicolor -0.956***
(0.215)
SpeciesDummy: virginica -1.394***
(0.286)
-------------------------------------------------
SpeciesDummy Fixed Effects Yes
-------------------------------------------------
N 150 150
R2 0.867 0.863
Within-R2 0.652
-------------------------------------------------regtable(rr5, rr6; keep=[r": ", r" & "])
# output
------------------------------------------------
SepalLength
-------------------
(1) (2)
------------------------------------------------
SpeciesDummy: versicolor -0.956***
(0.215)
SpeciesDummy: virginica -1.394***
(0.286)
SepalWidth & PetalLength -0.085*
(0.040)
------------------------------------------------
SpeciesDummy Fixed Effects Yes
------------------------------------------------
Controls Yes Yes
------------------------------------------------
N 150 150
R2 0.867 0.863
Within-R2 0.652
------------------------------------------------By Integer
Specifying an integer allows the selection of specific coefficients:
regtable(rr1, rr2, rr3, rr4; drop=[3])
# output
------------------------------------------------------------------------
SepalLength SepalWidth
------------------------------ ----------
(1) (2) (3) (4)
------------------------------------------------------------------------
SepalWidth 0.804*** 0.432*** 0.719***
(0.106) (0.081) (0.155)
PetalLength 0.776*** 1.047*** -0.188*
(0.064) (0.143) (0.083)
SepalWidth & PetalLength -0.070
(0.041)
SepalLength 0.378***
(0.066)
------------------------------------------------------------------------
SpeciesDummy Fixed Effects Yes Yes Yes Yes
------------------------------------------------------------------------
Controls Yes Yes
------------------------------------------------------------------------
N 150 150 150 150
R2 0.726 0.863 0.870 0.635
Within-R2 0.281 0.642 0.659 0.391
------------------------------------------------------------------------In typical arrays, Julia specifies the end argument to access the last argument. This does not work without direct access to the array, so this package provides an :end symbol that is handled similarly:
regtable(rr1, rr2, rr3, rr4; keep=[1, :end, (:end, 2)])
# output
------------------------------------------------------------------------
SepalLength SepalWidth
------------------------------ ----------
(1) (2) (3) (4)
------------------------------------------------------------------------
SepalWidth 0.804*** 0.432*** 0.719***
(0.106) (0.081) (0.155)
SepalLength 0.378***
(0.066)
PetalWidth -0.259 0.626***
(0.154) (0.123)
------------------------------------------------------------------------
SpeciesDummy Fixed Effects Yes Yes Yes Yes
------------------------------------------------------------------------
Controls Yes Yes Yes
------------------------------------------------------------------------
N 150 150 150 150
R2 0.726 0.863 0.870 0.635
Within-R2 0.281 0.642 0.659 0.391
------------------------------------------------------------------------The Tuple (:end, 2) is equivalent to end-2.
By Range
Specifying a range works similarly to an integer:
regtable(rr1, rr2, rr3, rr4; keep=[1:3])
# output
------------------------------------------------------------------------
SepalLength SepalWidth
------------------------------ ----------
(1) (2) (3) (4)
------------------------------------------------------------------------
SepalWidth 0.804*** 0.432*** 0.719***
(0.106) (0.081) (0.155)
PetalLength 0.776*** 1.047*** -0.188*
(0.064) (0.143) (0.083)
PetalWidth -0.259 0.626***
(0.154) (0.123)
------------------------------------------------------------------------
SpeciesDummy Fixed Effects Yes Yes Yes Yes
------------------------------------------------------------------------
Controls Yes Yes
------------------------------------------------------------------------
N 150 150 150 150
R2 0.726 0.863 0.870 0.635
Within-R2 0.281 0.642 0.659 0.391
------------------------------------------------------------------------There is also a special symbol for selecting a range at the end, :last. By itself, :last works the same as :end, but in a Tuple (:last, x) selects the last x coefficients:
regtable(rr1, rr2, rr3, rr4; keep=[1, (:last, 2)])
# output
------------------------------------------------------------------------
SepalLength SepalWidth
------------------------------ ----------
(1) (2) (3) (4)
------------------------------------------------------------------------
SepalWidth 0.804*** 0.432*** 0.719***
(0.106) (0.081) (0.155)
SepalWidth & PetalLength -0.070
(0.041)
SepalLength 0.378***
(0.066)
------------------------------------------------------------------------
SpeciesDummy Fixed Effects Yes Yes Yes Yes
------------------------------------------------------------------------
Controls Yes Yes Yes
------------------------------------------------------------------------
N 150 150 150 150
R2 0.726 0.863 0.870 0.635
Within-R2 0.281 0.642 0.659 0.391
------------------------------------------------------------------------Mixing keep, drop and order
As mentioned, keep is applied first, then drop and finally order. keep also will rearrange arguments, so integer and range arguments in order are applied to the resorted arguments from keep. It is also possible to mix the different types of selectors. For example, if you want the last coefficient and all coefficients that are interactions:
regtable(rr5, rr6; keep=[:end, r" & "])
# output
------------------------------------------------
SepalLength
-------------------
(1) (2)
------------------------------------------------
SpeciesDummy: virginica -1.394***
(0.286)
SepalWidth & PetalLength -0.085*
(0.040)
------------------------------------------------
SpeciesDummy Fixed Effects Yes
------------------------------------------------
Controls Yes Yes
------------------------------------------------
N 150 150
R2 0.867 0.863
Within-R2 0.652
------------------------------------------------Relabeled Coefficients
By default, if labels change the name of the arguments, then keep, drop and order should use the relabeled versions of the coefficients. For example, if the coefficients are relabeled:
regtable(rr1, rr2, rr3, rr4; labels=Dict("SepalWidth" => "SW", "PetalLength" => "PL"), keep=["SW", "PL"])
# output
---------------------------------------------------------------------
SepalLength SW
------------------------------ -------
(1) (2) (3) (4)
---------------------------------------------------------------------
SW 0.804*** 0.432*** 0.719***
(0.106) (0.081) (0.155)
PL 0.776*** 1.047*** -0.188*
(0.064) (0.143) (0.083)
---------------------------------------------------------------------
SpeciesDummy Fixed Effects Yes Yes Yes Yes
---------------------------------------------------------------------
Controls Yes Yes
---------------------------------------------------------------------
N 150 150 150 150
R2 0.726 0.863 0.870 0.635
Within-R2 0.281 0.642 0.659 0.391
---------------------------------------------------------------------To use the original coefficient names, set use_relabeled_values=false:
regtable(rr1, rr2, rr3, rr4; labels=Dict("SepalWidth" => "SW", "PetalLength" => "PL"), keep=["SepalWidth", "PetalLength"], use_relabeled_values=false)
# output
---------------------------------------------------------------------
SepalLength SW
------------------------------ -------
(1) (2) (3) (4)
---------------------------------------------------------------------
SW 0.804*** 0.432*** 0.719***
(0.106) (0.081) (0.155)
PL 0.776*** 1.047*** -0.188*
(0.064) (0.143) (0.083)
---------------------------------------------------------------------
SpeciesDummy Fixed Effects Yes Yes Yes Yes
---------------------------------------------------------------------
Controls Yes Yes
---------------------------------------------------------------------
N 150 150 150 150
R2 0.726 0.863 0.870 0.635
Within-R2 0.281 0.642 0.659 0.391
---------------------------------------------------------------------