[skip ci] Add a comment about the calculation method of accuracy results (#8080)

Signed-off-by: wangting0128 <ting.wang@zilliz.com>

tests/benchmark/milvus_benchmark/runners/utils.py

@@ -230,13 +230,21 @@ def gen_file_name(idx, dimension, data_type):
 def get_recall_value(true_ids, result_ids):
     """
     Use the intersection length
+    true_ids: neighbors taken from the dataset
+    result_ids: ids returned by query
     """
     sum_radio = 0.0
     for index, item in enumerate(result_ids):
         # tmp = set(item).intersection(set(flat_id_list[index]))
+
+        # Get the value of true_ids and the returned value to do the intersection
         tmp = set(true_ids[index]).intersection(set(item))
+
+        # Add up each ratio
         sum_radio = sum_radio + len(tmp) / len(item)
         # logger.debug(sum_radio)
+
+    # Calculate the average ratio and take three digits after the decimal point
     return round(sum_radio / len(result_ids), 3)