Julia 1.0 Programming Cookbook

How it works...

There are a wide number of methods that can be used to create DataFrame. Here are some of the most frequently used methods:

• By using keyword arguments, for example, DataFrame(a=[1, 2], b = "s") (the scalar in column :b will be converted to a vector of appropriate length)

• By passing column types, column names, and number of rows; for example, DataFrame([Int, String], [:a, :b], 2) will create a data frame with two columns that are uninitialized

• By passing a vector of data vectors and, optionally, column names, for example, DataFrame([[1, 2], ["a", "b"]], [:a, :b])

An important feature of DataFrame constructors is that if you pass a vector of data as a column, this vector is not copied. In other words, a variable is passed ...