OpenSearch/docs/reference/analysis/analyzers/snowball-analyzer.asciidoc

[[analysis-snowball-analyzer]]
=== Snowball Analyzer

An analyzer of type `snowball` that uses the
<<analysis-standard-tokenizer,standard
tokenizer>>, with
<<analysis-standard-tokenfilter,standard
filter>>,
<<analysis-lowercase-tokenfilter,lowercase
filter>>,
<<analysis-stop-tokenfilter,stop
filter>>, and
<<analysis-snowball-tokenfilter,snowball
filter>>.

The Snowball Analyzer is a stemming analyzer from Lucene that is
originally based on the snowball project from
http://snowballstem.org[snowballstem.org].

Sample usage:

[source,js]
--------------------------------------------------
{
    "index" : {
        "analysis" : {
            "analyzer" : {
                "my_analyzer" : {
                    "type" : "snowball",
                    "language" : "English"
                }
            }
        }
    }
}
--------------------------------------------------

The `language` parameter can have the same values as the
<<analysis-snowball-tokenfilter,snowball
filter>> and defaults to `English`. Note that not all the language
analyzers have a default set of stopwords provided.

The `stopwords` parameter can be used to provide stopwords for the
languages that have no defaults, or to simply replace the default set
with your custom list. Check <<analysis-stop-analyzer,Stop Analyzer>>
for more details. A default set of stopwords for many of these
languages is available from for instance
https://github.com/apache/lucene-solr/tree/trunk/lucene/analysis/common/src/resources/org/apache/lucene/analysis/[here]
and
https://github.com/apache/lucene-solr/tree/trunk/lucene/analysis/common/src/resources/org/apache/lucene/analysis/snowball[here.]

A sample configuration (in YAML format) specifying Swedish with
stopwords:

[source,js]
--------------------------------------------------
index :
    analysis :
        analyzer :
           my_analyzer:
                type: snowball
                language: Swedish
                stopwords: "och,det,att,i,en,jag,hon,som,han,på,den,med,var,sig,för,så,till,är,men,ett,om,hade,de,av,icke,mig,du,henne,då,sin,nu,har,inte,hans,honom,skulle,hennes,där,min,man,ej,vid,kunde,något,från,ut,när,efter,upp,vi,dem,vara,vad,över,än,dig,kan,sina,här,ha,mot,alla,under,någon,allt,mycket,sedan,ju,denna,själv,detta,åt,utan,varit,hur,ingen,mitt,ni,bli,blev,oss,din,dessa,några,deras,blir,mina,samma,vilken,er,sådan,vår,blivit,dess,inom,mellan,sådant,varför,varje,vilka,ditt,vem,vilket,sitta,sådana,vart,dina,vars,vårt,våra,ert,era,vilkas"
--------------------------------------------------