/// <summary>
/// Returns char frequency for given text
/// </summary>
/// <param name="text">Source text for statistic</param>
/// <param name="options">Text filtering options, see CharStat.Filter</param>
/// <returns>Dictionary, where char is key</returns>
public static Dictionary <char, double> GetStat(string text, CharStatOptions options = CharStatOptions.None)
{
var source = Filter(text, options);
return(source
.GroupBy(
x => x,
x => 1.0,
(c, g) => new
{
Char = c,
Frequency = g.Sum() / source.Length
})
.ToDictionary(x => x.Char, x => x.Frequency));
}
/// <summary>
/// Filters given string according to options. Surrogate pairs ignored
/// </summary>
/// <param name="text">Source string to filter, null string counts as empty</param>
/// <param name="options">Default is letters in lower case</param>
/// <returns>Filtered string, not null</returns>
public static string Filter(string text, CharStatOptions options = CharStatOptions.None)
{
var source = text ?? String.Empty;
if (!options.HasFlag(CharStatOptions.CaseSensetive))
{
source = source.ToLowerInvariant();
}
return(String.Concat(
source.Where(c =>
{
if (char.IsWhiteSpace(c))
{
return options.HasFlag(CharStatOptions.IncludeWhiteSpaces);
}
if (char.IsDigit(c))
{
return options.HasFlag(CharStatOptions.IncludeDigits);
}
return options.HasFlag(CharStatOptions.IncludeSymbols) || char.IsLetter(c);
})));
}
/// <summary>
/// Returns char frequency for given text
/// </summary>
/// <param name="text">Source text for statistic</param>
/// <param name="alphabetical">Sort order, by frequency descendant or alphabetical ascending</param>
/// <param name="options">Text filtering options, see CharStat.Filter</param>
/// <returns>Serializable model with ordered pairs</returns>
public static CharStatModel GetStatModel(string text, bool alphabetical = false, CharStatOptions options = CharStatOptions.None)
{
var source = Filter(text, options);
var query = source
.GroupBy(
x => x,
x => 1.0,
(c, g) => new CharPair()
{
Char = c,
Frequency = g.Sum() / source.Length
});
if (alphabetical)
{
query = query.OrderBy(x => x.Char);
}
else
{
query = query.OrderByDescending(x => x.Frequency);
}
return(new CharStatModel()
{
Pairs = query.ToList()
});
}
