This tutorial demonstrates how to use a DataFrame in Julia by creating a simple DataFrame with four columns, defining a function that adds a new column to the DataFrame by concatenating the values in other columns, and calling the function to add a new column to the DataFrame. The resulting DataFrame is then printed to the console.
Concatenate DataFrame Column Values in Julia Example
Here is an example of using a DataFrame in Julia:
using DataFrames
# Create a DataFrame with four columns: "a", "b", "c", and "d"
df = DataFrame(a = ["aa" for _ in 1:10], b = ["bb" for _ in 1:10],
c = ["cc" for _ in 1:10], d = ["dd" for _ in 1:10])
# Define a function that adds a new column to the DataFrame
function add_column(df::DataFrame, colname::Symbol, cols_to_concat::Vector)
df[!,colname] = (df[!, names(df)[cols_to_concat[1]]]
.* df[!, names(df)[cols_to_concat[2]]]
.* df[!, names(df)[cols_to_concat[3]]])
end
# Use the function to add a new column to the DataFrame
add_column(df, :add, [1, 4, 4])
# Print the updated DataFrame
println(df)This code creates a DataFrame with four columns: "a", "b", "c", and "d". It then defines a function add_column that takes a DataFrame, a column name (as a symbol), and a vector of indices for the columns to be concatenated. The function adds a new column to the DataFrame by concatenating the values in the specified columns. Finally, the function is called to add a new column called "add" to the DataFrame by concatenating the values in the first, fourth, and fourth columns. The updated DataFrame is then printed to the console.
Output:
10×5 DataFrame
Row │ a b c d add
│ String String String String String
─────┼────────────────────────────────────────
1 │ aa bb cc dd aadddd
2 │ aa bb cc dd aadddd
3 │ aa bb cc dd aadddd
4 │ aa bb cc dd aadddd
5 │ aa bb cc dd aadddd
6 │ aa bb cc dd aadddd
7 │ aa bb cc dd aadddd
8 │ aa bb cc dd aadddd
9 │ aa bb cc dd aadddd
10 │ aa bb cc dd aadddd
