C# reading .txt File FORMATTED

c#, file-io

Solution

EDIT 2 following your comment, that you wish to repeat the search 24 times a second.

First, let me caveat, if you are trying to play a stream of frames then looking up a list is the wrong approach. The right approach is beyond the scope of the question but, essentially you want to throttle the display of sequential data.

On the assumption that the values do not change, and your lookups are random, not sequential. You could try some code like this.

private readonly List<int> ids = new List<int>();
private readonly IList<double> values = new List<double>();

public void LoadData(string path)
{
    foreach (var line in File.ReadLines(path))
    {
        var pair = line.Split(' ');
        this.ids.Add(int.Parse(pair[0]));
        this.values.Add(double.Parse(pair[1]));
    }
}

public double Lookup(int id)
{
    return this.values[this.ids.FindIndex(i => i >= id)];
}

If more performance is required you could use the specialized binary search here.

EDIT after reading and hopefully, understanding

and assuming the frames are in ascending Id order.

double GetFrameValue(string path, int limit)
{
    string [] parts;
    foreach (var line in File.ReadLines(path))
    {
       parts = line.Split(' '); 
       var frameId = int.Parse[0];
       if (frameId >= limit)
       {
           break;
       }
    }

    return double.Parse(parts[1]);
}

This has the distinct advantage of only reading the file as far as necessary and not holding it all in memory. If you are going to read the file repeatedley at random frame positions then you'd be better off loading it all into some `Collection` with fast comparison performance, unless the file is very large.

How about,

IEnumerable<KeyValuePair<int, double>> ReadFrames(string path)
{
    foreach (var line in File.ReadLines(path))
    {
       var parts = line.Split(' '); 
       yield return new KeyValuePair<int, double>(
           int.Parse(parts[0]),
           double.Parse(parts[1]));
    }
}

var frames = new Dictionary<int, double>(ReadFrames("yourfile.txt"));

var frameIds = frames.Keys;
var values = frames.Values;

as stated in comments,

var frames = File.ReadLines("yourfile.txt")
    .Select(line => line.Split(' '))
    .ToDictionary(pair => int.Parse(pair[0]), pair => double.Parse(pair[1])); 

var frameIds = frames.Keys;
var values = frames.Values;

should work just as well.

Problem

Original source

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