private string AggregateNonNumeric(IEnumerable<string> data)
{
switch (NonNumericAggregationPolicy)
{
case NonNumericAggregation.Concatenate:
StringBuilder sb = new StringBuilder();
foreach (string s in data)
{
sb.Append(s);
}
return sb.ToString();
case NonNumericAggregation.KeepFirst:
return data.FirstOrDefault();
case NonNumericAggregation.Keywords:
StringBuilder allText = new StringBuilder();
foreach (string text in data)
{
allText.Append(text).Append(" ");
}
WordHistogram histogram = new WordHistogram();
return histogram.ToGeoJson(); // Pity, we only support aggregation to strings.
case NonNumericAggregation.Omit:
default:
return null;
}
}
