CSV to Double Array

[James_43]

Hi all,

I am able to pull data from a CSV file into a string array using the following code.

        public static string[,] ReadCSV(string filename)
        {
            //Read Text
            string whole_file = System.IO.File.ReadAllText(filename);

            //Split into Lines
            whole_file = whole_file.Replace('\n', '\r');
            string[] lines = whole_file.Split(new char[] { '\r' }, StringSplitOptions.RemoveEmptyEntries);

            //Calucluate Rows and Columns
            int num_rows = lines.Length;
            int num_cols = lines[0].Split(',').Length;

            //Allocate Array
            string[,] values = new string[num_rows, num_cols];

            //Load Array
            for (int r = 0; r < num_rows; r++)
            {
                string[] line_r = lines[r].Split(',');

                for (int c = 0; c < num_cols; c++)
                {
                    values[r, c] = line_r[c];
                }
            }

            //Return Values
            return values;

        }

This was based off an online example, so I'm not entirely sure what's happening here. I'm assuming that the data is stored as a string array with two required indexes [row, column]... Though I've never seen that, so it causing a bit of confusion.

Anyway, all the data in the CSV is a double, and I need the array to contain only doubles. How would I go about either converting the entire array, or populating it as a double in the first place?

[ddanbe]

Have a look at this snippet and the tip from deceptikon
Converting strings to doubles can be done this way
Happy reading!

[James_43]

That's really helpful thanks. I was hoping for something I can apply to the whole array, but I guess I have to convert each entry under a loop.

[James_43]

I've taken another look at this and now have the following code:

static void ReadCSV(string filename)
        {
            using (Microsoft.VisualBasic.FileIO.TextFieldParser parser = new Microsoft.VisualBasic.FileIO.TextFieldParser(filename))
            {
                string[] fields = null;

                parser.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited;
                parser.SetDelimiters(",");

                while (!parser.EndOfData)
                {
                    //Processing Row
                    fields = parser.ReadFields();
                    foreach (string field in fields)
                    { 
                       fields = AddItemToArray(fields, field);
                    }
                }
                Console.WriteLine(fields[17]);
            }
        }

The AddItemToArray code is:

        public static string[] AddItemToArray (string[] original, string itemToAdd)
        {
            string[] finalArray = new string[original.Length + 1];

            for (int i = 0; i < original.Length; i++)
            {
                finalArray[i] = original[i];
            }

            finalArray[finalArray.Length - 1] = itemToAdd;
            return finalArray;
        }

This should ensure that the final fields variable contains an array for every item in the CSV file. However, as you can see in the code I first posted, when I write Console.WriteLine(fields[17]); I get an index out of bounds error... The index only goes up to 4, which is the width of my columns... Why doesn't this store the complete data?

[ddanbe]

Btw my first two links in the previous post where switched. :)
Problem is in your AddItemToArray method. Her you define a local finalArray, which vanishes gracefully into oblivion, every time the method ends...
Better is to use a List:
Here is my code sketch on how to do it. Could use a little more erro checking, but I think you will find out how to proceed:

class Program
    {
        static List<double> Reals = new List<double>(); //-->use a List

        static void Main(string[] args)
        {
            ReadCSV("myfilePath");
        }

        static void ReadCSV(string filename)
        {
            using (Microsoft.VisualBasic.FileIO.TextFieldParser parser = new Microsoft.VisualBasic.FileIO.TextFieldParser(filename))
            {
                string[] fields = null;

                parser.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited;
                parser.SetDelimiters(",");

                while (!parser.EndOfData)
                {
                    //Processing Row
                    fields = parser.ReadFields();
                    foreach (string field in fields)
                    {
                        //fields = AddItemToArray(fields, field);--> remove
                        Reals.Add(Convert.ToDouble(field));
                    }
                }
                Console.WriteLine(fields[17]);
            }
        }

[James_43]

Hmmm. This actually thows up the same problem. Any index greater than the number of columns through an error. It only seems to work for one row.

When I simply write Console.WriteLine(fields); I just get System.Double[] show up.

[ddanbe]

Did you try Console.WriteLine(Reals[17]); instead of fields ?

[James_43]

Haha. Whoops. Yea, that works - thanks for your help with this!!

[ddanbe]

Did you try Console.WriteLine(Reals[17]); instead of fields ?
EDIT: IT HAPPENED AGAIN!!!