Update README.md

README.md

@@ -2,4 +2,41 @@
 license: mit
 ---
 
-PairRanker, trained on deberta-v3-large
+PairRanker used in llm-blender, trained on deberta-v3-large. 
+
+- Github: [https://github.com/yuchenlin/LLM-Blender](https://github.com/yuchenlin/LLM-Blender)
+- Paper: [https://arxiv.org/abs/2306.02561](https://arxiv.org/abs/2306.02561)
+
+## Usage Example
+Since PairRanker contains some custom layers and tokens. We recommend use our pairranker with our llm-blender python repo.
+Otherwise, loading it directly with hugging face `from_pretrained()` API will encounter errors.
+
+First install `llm-blender` by `pip install git+https://github.com/yuchenlin/LLM-Blender.git`
+Then use pairranker with the following code:
+```python
+import llm_blender
+# ranker config
+ranker_config = llm_blender.RankerConfig()
+ranker_config.ranker_type = "pairranker" # only supports pairranker now.
+ranker_config.model_type = "deberta"
+ranker_config.model_name = "microsoft/deberta-v3-large" # ranker backbone
+ranker_config.load_checkpoint = "llm-blender/pair-ranker" # hugging face hub model path or your local ranker checkpoint <your checkpoint path>
+ranker_config.cache_dir = "./hf_models" # hugging face model cache dir
+ranker_config.source_maxlength = 128
+ranker_config.candidate_maxlength = 128
+ranker_config.n_tasks = 1 # number of singal that has been used to train the ranker. This checkpoint is trained using BARTScore only, thus being 1.
+fuser_config = llm_blender.GenFuserConfig()
+# ignore fuser config as we don't use it here. You can load it if you want
+blender_config = llm_blender.BlenderConfig()
+# blender config
+blender_config.device = "cuda" # blender ranker and fuser device
+blender = llm_blender.Blender(blender_config, ranker_config, fuser_config)
+```
+Then you are good to use pairrankers with 
+- `blender.rank()` to rank candidates
+- `blender.compare()` to compare 2 candiates.
+See LLM-Blender Github [README.md](https://github.com/yuchenlin/LLM-Blender#rank-and-fusion)
+and jupyter file [blender_usage.ipynb](https://github.com/yuchenlin/LLM-Blender/blob/main/blender_usage.ipynb)
+for detailed usage examples.
+
+