Description
Queries the tag history system for information about the density of data. In other words, how much data is available for a given time span.
This function is called with a list of tag paths, and a start and end date. The result set is a two column dataset specifying the timestamp, and a relative weight. Each row is valid from the given time until the next row. The weight is normalized to a value of 1.0 for each tag with data during that time. Thus, for three tag paths passed in, if all tags were present during the span, the result would be 3.0.
This function accepts keyword-style invocation. See also: Functions / Keyword Invocation
Syntax
system.tag.queryTagDensity(paths, startDate, endDate)
Parameters
PySequence paths - An array of tag paths (strings) to query.
Date startDate - The start of the range to query.
Date endDate - The end of the range to query.
Returns
Dataset - A 2-column dataset consisting of a timestamp and a weight. Each row is valid until the next row. The weight is 1 point for each tag with data present.
Scope
All