CreateDataFrame.cs

This code shows how to create a DataFrame object and add data to it.

Index	Diameter(μm)	Elongation factor	Type
1	6.52	0.93	Nucleus
2	2.47	0.37	Mitochondrion
3	5.78	0.86	Nucleus

Then another Formula column is added to give the result of the multiplication of Diameter and Elongation factorcolumns.

using IOLink;
using System;
using System.Linq;
 
namespace Examples
{
    public class CreateDataFrame
    {
 
        // Create a DataFrame object with 4 columns, using given
        // values:
        // - Indexer (int)
        // - Diameter (double)
        // - Elongation Factor (double)
        // - Type (string)
        private static DataFrameView CreateDataFrameView(double[] diameterValues,
                                                         double[] elongFactValues,
                                                         string[] typeValues)
        {
            // each list should have the same size
            if (diameterValues.Length != elongFactValues.Length
                || diameterValues.Length != typeValues.Length)
            {
                throw new ApplicationException("All lists should have the same size");
            }
 
            // create a DataFrame object with 4 columns and the
            // number of rows equal to the size of the given data
            string[] columNames = new string[] { "Index", "Diameter", "Elongation Factor", "Type" };
            DataType[] columnTypes = new DataType[] {
                DataTypeId.UINT64, DataTypeId.DOUBLE, DataTypeId.DOUBLE, DataTypeId.UTF8_STRING
            };
            var dataFrame = DataFrameViewFactory.Allocate(
              new Vector2u64((ulong)columnTypes.Length, (ulong)diameterValues.Length),
              columNames,
              columnTypes);
 
            // set the unit of the Diameter column
            dataFrame.SetUnit(dataFrame.ColumnIndex("Diameter"), "μm");
 
            ulong[] indexValues = new ulong[diameterValues.Length];
            for (ulong i = 0; i < (ulong)diameterValues.Length; ++i)
            {
                indexValues[i] = i + 1;
            }
 
            // fill each column with the given data, one shot
            dataFrame.Write(
              dataFrame.ColumnIndex("Index"), 0, (uint)indexValues.Length, indexValues);
            dataFrame.Write(
              dataFrame.ColumnIndex("Diameter"), 0, (uint)diameterValues.Length, diameterValues);
            dataFrame.Write(dataFrame.ColumnIndex("Elongation Factor"),
                            0,
                            (uint)elongFactValues.Length,
                            elongFactValues);
            dataFrame.Write(dataFrame.ColumnIndex("Type"), 0, (uint)typeValues.Length, typeValues);
 
            return dataFrame;
        }
 
        // Add a new column "formula" to the DataFrame object
        // which is the result of the multiplication of the
        // Diameter and Elongation Factor columns
        private static void AddFormulaToDataFrame(DataFrameView df)
        {
            // add a new column "formula" to the DataFrame object
            df.AddColumn("Formula", DataTypeId.DOUBLE);
 
            // get the number of rows in the DataFrame object
            ulong numRows = df.Shape[1];
 
            // create a vector to store the result of the
            // multiplication of the Diameter and Elongation
            // Factor columns
            double[] formulaValues = new double[numRows];
 
            // calculate the result of the multiplication of the
            // Diameter and Elongation Factor columns
            for (uint i = 0; i < (uint)numRows; ++i)
            {
                formulaValues[i]
                  = df.At<double>("Diameter", i) * df.At<double>("Elongation Factor", i);
                // write the result of the multiplication of the
                // Diameter and Elongation Factor columns to the
                // new column "formula"
                df.SetAt<double>("Formula", i, formulaValues[i]);
            }
        }
 
        public static void Main(string[] args)
        {
            // create dataframe
            DataFrameView df
              = CreateDataFrameView(new double[] { 6.52, 2.47, 5.78 },
                                    new double[] { 0.93, 0.37, 0.86 },
                                    new string[] { "Nucleus", "Mitochondrion", "Nucleus" });
 
            // print the DataFrame object
            Console.WriteLine(df.ToString());
 
            // add one column "formula" to the DataFrame object
            // which contains the result of the multiplication of
            // the Diameter and Elongation Factor columns
            AddFormulaToDataFrame(df);
 
            // print the DataFrame object after adding the new
            // column "formula"
            Console.WriteLine(df.ToString());
        }
    }
}