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Stop analyzer

The stop analyzer removes a predefined list of stopwords. This analyzer consists of a lowercase tokenizer and a stop token filter.

Parameters

You can configure a stop analyzer with the following parameters.

Parameter Required/Optional Data type Description
stopwords Optional String or list of strings A string specifying a predefined list of stopwords (such as _english_) or an array specifying a custom list of stopwords. Default is _english_.
stopwords_path Optional String The path (absolute or relative to the config directory) to the file containing a list of stopwords.

Example

Use the following command to create an index named my_stop_index with a stop analyzer:

PUT /my_stop_index
{
  "mappings": {
    "properties": {
      "my_field": {
        "type": "text",
        "analyzer": "stop"
      }
    }
  }
}

Configuring a custom analyzer

Use the following command to configure an index with a custom analyzer that is equivalent to a stop analyzer:

PUT /my_custom_stop_analyzer_index
{
  "settings": {
    "analysis": {
      "analyzer": {
        "my_custom_stop_analyzer": {
          "tokenizer": "lowercase",
          "filter": [
            "stop"
          ]
        }
      }
    }
  },
  "mappings": {
    "properties": {
      "my_field": {
        "type": "text",
        "analyzer": "my_custom_stop_analyzer"
      }
    }
  }
}

Generated tokens

Use the following request to examine the tokens generated using the analyzer:

POST /my_custom_stop_analyzer_index/_analyze
{
  "analyzer": "my_custom_stop_analyzer",
  "text": "The large turtle is green and brown"
}

The response contains the generated tokens:

{
  "tokens": [
    {
      "token": "large",
      "start_offset": 4,
      "end_offset": 9,
      "type": "word",
      "position": 1
    },
    {
      "token": "turtle",
      "start_offset": 10,
      "end_offset": 16,
      "type": "word",
      "position": 2
    },
    {
      "token": "green",
      "start_offset": 20,
      "end_offset": 25,
      "type": "word",
      "position": 4
    },
    {
      "token": "brown",
      "start_offset": 30,
      "end_offset": 35,
      "type": "word",
      "position": 6
    }
  ]
}

Specifying stopwords

The following example request specifies a custom list of stopwords:

PUT /my_new_custom_stop_index
{
  "settings": {
    "analysis": {
      "analyzer": {
        "my_custom_stop_analyzer": {
          "type": "stop",                     
          "stopwords": ["is", "and", "was"]
        }
      }
    }
  },
  "mappings": {
    "properties": {
      "description": {
        "type": "text",
        "analyzer": "my_custom_stop_analyzer" 
      }
    }
  }
}

The following example request specifies a path to the file containing stopwords:

PUT /my_new_custom_stop_index
{
  "settings": {
    "analysis": {
      "analyzer": {
        "my_custom_stop_analyzer": {
          "type": "stop",                     
          "stopwords_path": "stopwords.txt"
        }
      }
    }
  },
  "mappings": {
    "properties": {
      "description": {
        "type": "text",
        "analyzer": "my_custom_stop_analyzer" 
      }
    }
  }
}

In this example, the file is located in the config directory. You can also specify a full path to the file.

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