GetAvgSentiment

Program.cs

string[] symbolsUniverse = new[] { "AAPL", "VOD", "ADBE", "GRPN", "META", "ACER", "GOOG", "BP" };
List<string> GenerateSymbols(int number)
{
    var symbols = new List<string>();
    for (int i = 0; i < symbolsUniverse.Length; i++)
    {
        var bit = 1 << i;
        if ((number & bit) == bit)
            symbols.Add(symbolsUniverse[i]);
    }
    return symbols;
}

var rand = new Random(42);

var articles = Enumerable.Range(1, 255).Select(i => new ArticleWithSentiment(
    GenerateSymbols(i),
    new SentimentResponse(rand.NextDouble(), rand.NextDouble(), (SentimentResult)(i % 4))
)).ToList();

var symbol = "AAPL";


var articlesAboutSymbol = articles.Where(a => a.Symbols.Contains(symbol)).ToList();

var weights = articlesAboutSymbol.Select(a => a.Weight);

var positivesAvg = articlesAboutSymbol.Select(a => a.Response.PositiveScore * a.Weight).Sum() / weights.Sum();
var negativesAvg = articlesAboutSymbol.Select(a => a.Response.NegativeScore * a.Weight).Sum() / weights.Sum();

var sentimentsAvg = articlesAboutSymbol.Select(a => (int)a.Response.Sentiment * a.Weight).Sum() / weights.Sum();

var sentimentsAvgEnum = (SentimentResult)(int)Math.Round(sentimentsAvg);


Console.Read();

public record ArticleWithSentiment(IReadOnlyList<string> Symbols, SentimentResponse Response)
{
    public double Weight => 1.0 / (Symbols.Count * Symbols.Count);
}
public record SentimentResponse(double PositiveScore, double NegativeScore, SentimentResult Sentiment);
public enum SentimentResult { Neutral = 0, Positive = 1, Negative = 2, Mixed = 3, }