Automatic Model Conversion

Senpy includes support for emotion and sentiment conversion. When a user requests a specific model, senpy will choose a strategy to convert the model that the service usually outputs and the model requested by the user.

Out of the box, senpy can convert from the emotionml:pad (pleasure-arousal-dominance) dimensional model to emoml:big6 (Ekman’s big-6) categories, and vice versa. This specific conversion uses a series of dimensional centroids (emotionml:pad) for each emotion category (emotionml:big6). A dimensional value is converted to a category by looking for the nearest centroid. The centroids are calculated according to this article:

Kim, S. M., Valitutti, A., & Calvo, R. A. (2010, June).
Evaluation of unsupervised emotion models to textual affect recognition.
In Proceedings of the NAACL HLT 2010 Workshop on Computational Approaches to Analysis and Generation of Emotion in Text (pp. 62-70).
Association for Computational Linguistics.

It is possible to add new conversion strategies by Developing a conversion plugin.

Use

Consider the following query to an emotion service: http://senpy.gsi.upm.es/api/emotion-anew?i=good

The requested plugin (emotion-random) returns emotions using the VAD space (FSRE dimensions in EmotionML):

 [
   {
     "@type": "EmotionSet",
     "onyx:hasEmotion": [
       {
         "@type": "Emotion",
         "emoml:pad-dimensions_arousal": 5.43,
         "emoml:pad-dimensions_dominance": 6.41,
         "emoml:pad-dimensions_pleasure": 7.47,
         "prov:wasGeneratedBy": "prefix:Analysis_1562744784.8789825"
       }
     ],
     "prov:wasGeneratedBy": "prefix:Analysis_1562744784.8789825"
   }
]

To get the equivalent of these emotions in Ekman’s categories (i.e., Ekman’s Big 6 in EmotionML), we’d do this:

http://senpy.gsi.upm.es/api/emotion-anew?i=good&emotion-model=emoml:big6

This call, provided there is a valid conversion plugin from Ekman’s to VAD, would return something like this:

[
   {
     "@type": "EmotionSet",
     "onyx:hasEmotion": [
       {
         "@type": "Emotion",
         "onyx:algorithmConfidence": 4.4979,
         "onyx:hasEmotionCategory": "emoml:big6happiness"
       }
     ],
     "prov:wasDerivedFrom": {
       "@id": "Emotions0",
       "@type": "EmotionSet",
       "onyx:hasEmotion": [
         {
           "@id": "Emotion0",
           "@type": "Emotion",
           "emoml:pad-dimensions_arousal": 5.43,
           "emoml:pad-dimensions_dominance": 6.41,
           "emoml:pad-dimensions_pleasure": 7.47,
           "prov:wasGeneratedBy": "prefix:Analysis_1562745220.1553965"
         }
       ],
       "prov:wasGeneratedBy": "prefix:Analysis_1562745220.1553965"
     },
     "prov:wasGeneratedBy": "prefix:Analysis_1562745220.1570725"
   }
 ]

That is called a full response, as it simply adds the converted emotion alongside. It is also possible to get the original emotion nested within the new converted emotion, using the conversion=nested parameter:

http://senpy.gsi.upm.es/api/emotion-anew?i=good&emotion-model=emoml:big6&conversion=nested

 [
      {
        "@type": "EmotionSet",
        "onyx:hasEmotion": [
          {
            "@type": "Emotion",
            "onyx:algorithmConfidence": 4.4979,
            "onyx:hasEmotionCategory": "emoml:big6happiness"
          }
        ],
        "prov:wasDerivedFrom": {
          "@id": "Emotions0",
          "@type": "EmotionSet",
          "onyx:hasEmotion": [
            {
              "@id": "Emotion0",
              "@type": "Emotion",
              "emoml:pad-dimensions_arousal": 5.43,
              "emoml:pad-dimensions_dominance": 6.41,
              "emoml:pad-dimensions_pleasure": 7.47,
              "prov:wasGeneratedBy": "prefix:Analysis_1562744962.896306"
            }
          ],
          "prov:wasGeneratedBy": "prefix:Analysis_1562744962.896306"
        },
        "prov:wasGeneratedBy": "prefix:Analysis_1562744962.8978968"
      }
]

Lastly, conversion=filtered would only return the converted emotions.

[
   {
     "@type": "EmotionSet",
     "onyx:hasEmotion": [
       {
         "@type": "Emotion",
         "onyx:algorithmConfidence": 4.4979,
         "onyx:hasEmotionCategory": "emoml:big6happiness"
       }
     ],
     "prov:wasGeneratedBy": "prefix:Analysis_1562744925.7322266"
   }
]

Developing a conversion plugin

Conversion plugins are discovered by the server just like any other plugin. The difference is the slightly different API, and the need to specify the source and target of the conversion. For instance, an emotion conversion plugin needs the following:

---
onyx:doesConversion:
  - onyx:conversionFrom: emoml:big6
    onyx:conversionTo: emoml:fsre-dimensions
  - onyx:conversionFrom: emoml:fsre-dimensions
    onyx:conversionTo: emoml:big6

class MyConversion(EmotionConversionPlugin):

    def convert(self, emotionSet, fromModel, toModel, params):
        pass

More implementation details are shown in the centroids plugin.