Added evaluation benchmark (#29)

* add evaluation benchmark

* added eval benchmark

* revert file

Author: shahules786

tests/benchmarks/benchmark_eval.py

@@ -0,0 +1,22 @@
+from datasets import arrow_dataset, load_dataset
+from torch.cuda import is_available
+
+from ragas.metrics import Evaluation, bert_score, edit_ratio, rougeL
+from ragas.metrics.factual import EntailmentScore
+
+DEVICE = "cuda" if is_available() else "cpu"
+entailment_score = EntailmentScore(device=DEVICE, batch_size=2)
+# q_square = Qsquare(device=DEVICE, batch_size=2)
+
+DS = load_dataset("explodinggradients/ragas-webgpt", split="train")
+assert isinstance(DS, arrow_dataset.Dataset), "Not an arrow_dataset"
+DS = DS.select(range(500))
+
+if __name__ == "__main__":
+    e = Evaluation(
+        metrics=[rougeL, edit_ratio, bert_score, entailment_score],
+        batched=True,
+        batch_size=64,
+    )
+    result = e.eval(DS["ground_truth"], DS["generated_text"])
+    print(result)