/// <summary>EP message to <c>probTrue</c>.</summary>
 /// <param name="sample">Incoming message from <c>sample</c>. Must be a proper distribution. If any element is uniform, the result will be uniform.</param>
 /// <param name="probTrue">Incoming message from <c>probTrue</c>.</param>
 /// <param name="result">Modified to contain the outgoing message.</param>
 /// <returns>
 ///   <paramref name="result" />
 /// </returns>
 /// <remarks>
 ///   <para>The outgoing message is a distribution matching the moments of <c>probTrue</c> as the random arguments are varied. The formula is <c>proj[p(probTrue) sum_(sample) p(sample) factor(sample,probTrue)]/p(probTrue)</c>.</para>
 /// </remarks>
 /// <exception cref="ImproperMessageException">
 ///   <paramref name="sample" /> is not a proper distribution.</exception>
 public static SparseBetaList ProbTrueAverageConditional([SkipIfUniform] SparseBernoulliList sample, SparseBetaList probTrue, SparseBetaList result)
 {
     result.SetToFunction(sample, probTrue, (s, pt) => BernoulliFromBetaOp.ProbTrueAverageConditional(s, pt));
     return(result);
 }
 /// <summary>EP message to <c>probTrue</c>.</summary>
 /// <param name="sample">Constant value for <c>sample</c>.</param>
 /// <param name="result">Modified to contain the outgoing message.</param>
 /// <returns>
 ///   <paramref name="result" />
 /// </returns>
 /// <remarks>
 ///   <para>The outgoing message is the factor viewed as a function of <c>probTrue</c> conditioned on the given values.</para>
 /// </remarks>
 public static SparseBetaList ProbTrueAverageConditional(IList <int> sample, SparseBetaList result)
 {
     result.SetToFunction(BernoulliIntegerSubset.SubsetToList(sample, result.Count), s => BernoulliFromBetaOp.ProbTrueAverageConditional(s));
     return(result);
 }
 /// <summary>EP message to <c>probTrue</c>.</summary>
 /// <param name="sample">Constant value for <c>sample</c>.</param>
 /// <param name="result">Modified to contain the outgoing message.</param>
 /// <returns>
 ///   <paramref name="result" />
 /// </returns>
 /// <remarks>
 ///   <para>The outgoing message is the factor viewed as a function of <c>probTrue</c> conditioned on the given values.</para>
 /// </remarks>
 public static SparseBetaList ProbTrueAverageConditional(ISparseList <bool> sample, SparseBetaList result)
 {
     result.SetToFunction(sample, s => BernoulliFromBetaOp.ProbTrueAverageConditional(s));
     return(result);
 }