/// <summary>EP message to <c>str</c>.</summary>
/// <param name="sub">Constant value for <c>sub</c>.</param>
/// <param name="start">Constant value for <c>start</c>.</param>
/// <param name="length">Constant value for <c>length</c>.</param>
/// <returns>The outgoing EP message to the <c>str</c> argument.</returns>
/// <remarks>
/// <para>The outgoing message is the factor viewed as a function of <c>str</c> conditioned on the given values.</para>
/// </remarks>
public static StringDistribution StrAverageConditional(string sub, int start, int length)
{
Argument.CheckIfNotNull(sub, "sub");
Argument.CheckIfInRange(start >= 0, "start", "Start index must be non-negative.");
Argument.CheckIfInRange(length >= 0, "length", "Length must be non-negative.");
if (sub.Length != length)
{
return(StringDistribution.Zero());
}
StringDistribution result = StringDistribution.Any(minLength: start, maxLength: start);
result.AppendInPlace(sub);
result.AppendInPlace(StringDistribution.Any());
return(result);
}
/// <summary>
/// Creates a string distribution <c>P(s) = \prod_i P_i(s_i)^I[i != j]</c>,
/// where <c>P_i(c)</c> is a given array of character distributions and <c>j</c> is a given position in the array.
/// </summary>
/// <param name="characters">The distributions over individual characters.</param>
/// <param name="excludedPos">The character to skip.</param>
/// <returns>The created distribution.</returns>
private static StringDistribution GetCharWeighter(IList <DiscreteChar> characters, int excludedPos)
{
StringDistribution result = StringDistribution.Empty();
for (int i = 0; i < characters.Count; ++i)
{
result.AppendInPlace(i == excludedPos ? DiscreteChar.Uniform() : characters[i]);
}
return(result);
}
/// <include file='FactorDocs.xml' path='factor_docs/message_op_class[@name="StringFromArrayOp"]/message_doc[@name="StrAverageConditional(IList{DiscreteChar})"]/*'/>
public static StringDistribution StrAverageConditional(IList <DiscreteChar> characters)
{
StringDistribution result = StringDistribution.Empty();
for (int i = 0; i < characters.Count; ++i)
{
result.AppendInPlace(characters[i]);
}
return(result);
}
