Update README.md

README.md

@@ -10,4 +10,96 @@ XGLM-4.5B is a multilingual autoregressive language model (with 4.5 billion para
 
 ## Model card
 
-For intended usage of the model, please refer to the [model card](https://github.com/pytorch/fairseq/blob/main/examples/xglm/model_card.md) released by the XGLM-4.5B development team. 
+For intended usage of the model, please refer to the [model card](https://github.com/pytorch/fairseq/blob/main/examples/xglm/model_card.md) released by the XGLM-4.5B development team. 
+
+## Example (COPA)
+The following snippet shows how to evaluate our models (GPT-3 style, zero-shot) on the Choice of Plausible Alternatives (COPA) task, using examples in English, Chinese and Hindi.
+
+```python
+import torch
+import torch.nn.functional as F
+
+from transformers import XGLMTokenizer, XGLMForCausalLM
+
+tokenizer = XGLMTokenizer.from_pretrained("facebook/xglm-4.5B")
+model = XGLMForCausalLM.from_pretrained("facebook/xglm-4.5B")
+
+data_samples = {
+    'en': [
+        {
+            "premise": "I wanted to conserve energy.",
+            "choice1": "I swept the floor in the unoccupied room.",
+            "choice2": "I shut off the light in the unoccupied room.",
+            "question": "effect",
+            "label": "1"
+        },
+        {
+            "premise": "The flame on the candle went out.",
+            "choice1": "I blew on the wick.",
+            "choice2": "I put a match to the wick.",
+            "question": "cause",
+            "label": "0"
+        }
+    ],
+    'zh': [
+        {
+            "premise": "我想节约能源。",
+            "choice1": "我在空着的房间里扫了地板。",
+            "choice2": "我把空房间里的灯关了。",
+            "question": "effect",
+            "label": "1"
+        },
+        {
+            "premise": "蜡烛上的火焰熄灭了。",
+            "choice1": "我吹灭了灯芯。",
+            "choice2": "我把一根火柴放在灯芯上。",
+            "question": "cause",
+            "label": "0"
+        }
+    ],
+    'hi': [
+        {
+            "premise": "M te vle konsève enèji.",
+            "choice1": "Mwen te fin baleye chanm lib la.",
+            "choice2": "Mwen te femen limyè nan chanm lib la.",
+            "question": "effect",
+            "label": "1"
+        },
+        {
+            "premise": "Flam bouji a te etenn.",
+            "choice1": "Mwen te soufle bouji a.",
+            "choice2": "Mwen te limen mèch bouji a.",
+            "question": "cause",
+            "label": "0"
+        }
+    ]
+}
+
+def get_logprobs(prompt):
+    inputs = tokenizer(prompt, return_tensors="pt")
+    input_ids, output_ids = inputs["input_ids"], inputs["input_ids"][:, 1:]
+    outputs = model(**inputs, labels=input_ids)
+    logits = outputs.logits
+    logprobs = torch.gather(F.log_softmax(logits, dim=2), 2, output_ids.unsqueeze(2))
+    return logprobs
+
+# Zero-shot evaluation for the Choice of Plausible Alternatives (COPA) task.
+# A return value of 0 indicates that the first alternative is more plausible,
+# while 1 indicates that the second alternative is more plausible.
+def COPA_eval(prompt, alternative1, alternative2):
+    lprob1 = get_logprobs(prompt + "\n" + alternative1).sum()
+    lprob2 = get_logprobs(prompt + "\n" + alternative2).sum()
+    return 0 if lprob1 > lprob2 else 1
+
+for lang in data_samples_long:
+    for idx, example in enumerate(data_samples_long[lang]):
+        predict = COPA_eval(example["premise"], example["choice1"], example["choice2"])
+        print(f'{lang}-{idx}', predict, example['label'])
+        
+# en-0 1 1
+# en-1 0 0
+# zh-0 1 1
+# zh-1 0 0
+# hi-0 1 1
+# hi-1 0 0
+```