Trying out DataFrame

TryingOutDataFrame.cs

using System;
using Microsoft.Data.Analysis;

namespace TryingOutDataFrame
{
    class Program
    {

        static void Main(string[] args)
        {
            // Data
            string[] names = { "John", "Ahmed", "Chris", "Albert" };
            int[] salaries = { 20000, 30000, 40000, 10000 };
            DateTime[] birthdays = { DateTime.Parse("23/4/1990"), DateTime.Parse("4/5/1982"),
                DateTime.Parse("2/1/1980"), DateTime.Parse("9/10/1994") };
            string[] departments = { "Development", "Development", "HR", null };

            var idColumn1 = new PrimitiveDataFrameColumn<int>("Id", new int[] { 1, 2, 3, 4 });
            var nameColumn = new StringDataFrameColumn("Name", names);
            var birthdayColumn = new PrimitiveDataFrameColumn<DateTime>("Birthday", birthdays);
            var salaryColumn = new PrimitiveDataFrameColumn<int>("Salary", salaries);

            var idColumn2 = new PrimitiveDataFrameColumn<int>("EmployeeId", new int[] { 3, 1, 2, 4 });
            var departmentColumn = new StringDataFrameColumn("Department", departments);

            var employeesDf = new DataFrame(idColumn1, nameColumn, birthdayColumn, salaryColumn);
            var departmentsDf = new DataFrame(idColumn2, departmentColumn);

            employeesDf.PrettyPrint();
            departmentsDf.PrettyPrint();

            employeesDf.Info().PrettyPrint();
            departmentsDf.Info().PrettyPrint();

            employeesDf.Description().PrettyPrint();

            // Fill nulls
            departmentColumn.FillNulls("Other", inPlace: true);

            // Create a new column by applying a function
            var currentYear = DateTime.Now.Year;
            employeesDf["Age"] = birthdayColumn.Apply(d => currentYear - d.Year);
            employeesDf.PrettyPrint();

            // Normalize salary between 0 and 1
            var minSalary = (float)(int)salaryColumn.Min();
            var maxSalary = (int)salaryColumn.Max();
            employeesDf["NormalizedSalary"] = (salaryColumn - minSalary) / (maxSalary - minSalary);
            employeesDf.PrettyPrint();

            // Join 2 dataframes
            var df = employeesDf.Merge<int>(departmentsDf, "Id", "EmployeeId", joinAlgorithm: JoinAlgorithm.Inner);
            df.PrettyPrint();

            // Drop column and sort by id
            df.Columns.Remove("EmployeeId");
            df = df.Sort("Id");
            df.PrettyPrint();

            // Mean salary by department
            var employeesByDepartment = df.GroupBy("Department");
            employeesByDepartment.Mean("Salary").PrettyPrint();

            // Value counts of department
            departmentColumn.ValueCounts().PrettyPrint();

            // Sample rows - sometimes gives duplicate rows
            df.Sample(2).PrettyPrint();
        }

    }
}