https://pizza.rs/tags/string_stats/Recent content in String_stats on INFINI PizzaHugoenhttps://pizza.rs/docs/references/aggregation/metric/string-stats/Mon, 01 Jan 0001 00:00:00 +0000https://pizza.rs/docs/references/aggregation/metric/string-stats/<h1 id="string-stats-aggregation"> String stats aggregation <a class="anchor" href="#string-stats-aggregation">#</a> </h1> <p>A multi-value metrics aggregation computing length and character statistics over keyword/string values: count, min/max/avg length and Shannon entropy of the character distribution.</p> <h2 id="how-it-works"> How it works <a class="anchor" href="#how-it-works">#</a> </h2> <p>Every document that has a string value for the field contributes one string. Over those strings the engine reports:</p> <ul> <li><code>count</code> — how many values were seen (documents without the field are skipped, not counted);</li> <li><code>min_length</code>, <code>max_length</code>, <code>avg_length</code> — length statistics in UTF-8 <strong>bytes</strong>, so a non-ASCII character counts as its encoded width;</li> <li><code>entropy</code> — Shannon entropy of the pooled character frequencies, in <strong>bits</strong>: <code>-Σ p(c) · log2 p(c)</code> over the share <code>p(c)</code> of each character across all strings. Constant text gives <code>0</code>; text where every character is equally likely gives <code>log2(alphabet size)</code>.</li> </ul> <p>The character frequencies are pooled across all contributing values before the entropy is taken, so repetition across documents counts: the teaching <code>type</code> field repeats the same few words 120 times and still scores ≈3.22 bits.</p>