Is there any R like subset function in Julia?

Question

Consider the iris dataset in R. (available in Julia via RDatasets package). Suppose I want to get the observations of "Sepal.Length" and "Petal.Width" for Species "setosa". In R, I can do it by:

subset(iris, Species=="setosa", select = c(Sepal.Length, Petal.Width))

Is there any similar function in Julia for the same job?

Reza Afzalan Reza Afzalan · Accepted Answer · 2015-10-13T10:13:19

using RDatasets
iris = dataset("datasets","iris") # typeof(iris) => DataFrames.DataFrame 
subset=iris[iris[:Species].=="setosa",[:PetalLength,:PetalWidth]]

Notes(1) refer to RDatasets.jl:

In order to load one of the data sets included in the RDatasets package, you will need to have the DataFrames package installed. This package is automatically installed as a dependency of the RDatasets package if you install RDatasets as follows:

Pkg.add("RDatasets")

Note(2): as datasets in RDatasets package are of DataFrame type, so one can use syntax from dataframesjl to create Subsets

EDIT:

As @jverzani commented, using DataFramesMeta unveils a set of macros with SQL semantics that guides users to write query statements in more familiar styles. e.g the above command would be @ix(iris, :Species.=="setosa", [:PetalLength,:PetalWidth])

Is there any R like subset function in Julia?

1 Answers