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Co-authored-by: Lysandre Debut <lysandre.debut@reseau.eseo.fr>

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Co-authored-by: Lysandre Debut <lysandre.debut@reseau.eseo.fr>

docs/source/en/model_doc/nystromformer.md

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+
+# Nyströmformer
+
+## Overview
+
+The Nyströmformer model was proposed in [*Nyströmformer: A Nyström-Based Algorithm for Approximating Self-Attention*](https://arxiv.org/abs/2102.03902) by Yunyang Xiong, Zhanpeng Zeng, Rudrasis Chakraborty, Mingxing Tan, Glenn
+Fung, Yin Li, and Vikas Singh.
+
+The abstract from the paper is the following:
+
+*Transformers have emerged as a powerful tool for a broad range of natural language processing tasks. A key component
+that drives the impressive performance of Transformers is the self-attention mechanism that encodes the influence or
+dependence of other tokens on each specific token. While beneficial, the quadratic complexity of self-attention on the
+input sequence length has limited its application to longer sequences -- a topic being actively studied in the
+community. To address this limitation, we propose Nyströmformer -- a model that exhibits favorable scalability as a
+function of sequence length. Our idea is based on adapting the Nyström method to approximate standard self-attention
+with O(n) complexity. The scalability of Nyströmformer enables application to longer sequences with thousands of
+tokens. We perform evaluations on multiple downstream tasks on the GLUE benchmark and IMDB reviews with standard
+sequence length, and find that our Nyströmformer performs comparably, or in a few cases, even slightly better, than
+standard self-attention. On longer sequence tasks in the Long Range Arena (LRA) benchmark, Nyströmformer performs
+favorably relative to other efficient self-attention methods. Our code is available at this https URL.*
+
+This model was contributed by [novice03](https://huggingface.co/novice03). The original code can be found [here](https://github.com/mlpen/Nystromformer).
+
+## Documentation resources
+
+- [Text classification task guide](../tasks/sequence_classification)
+- [Token classification task guide](../tasks/token_classification)
+- [Question answering task guide](../tasks/question_answering)
+- [Masked language modeling task guide](../tasks/masked_language_modeling)
+- [Multiple choice task guide](../tasks/multiple_choice)
+
+## NystromformerConfig
+
+[[autodoc]] NystromformerConfig
+
+## NystromformerModel
+
+[[autodoc]] NystromformerModel
+    - forward
+
+## NystromformerForMaskedLM
+
+[[autodoc]] NystromformerForMaskedLM
+    - forward
+
+## NystromformerForSequenceClassification
+
+[[autodoc]] NystromformerForSequenceClassification
+    - forward
+
+## NystromformerForMultipleChoice
+
+[[autodoc]] NystromformerForMultipleChoice
+    - forward
+
+## NystromformerForTokenClassification
+
+[[autodoc]] NystromformerForTokenClassification
+    - forward
+
+## NystromformerForQuestionAnswering
+
+[[autodoc]] NystromformerForQuestionAnswering
+    - forward