Add quick start guide

README.md

@@ -14,6 +14,31 @@ The motivation of the genomics long range benchmark (LRB) is to compile a set of
 While serving as a strong basis of evaluation, the benchmark must also be efficient and user-friendly. 
 To achieve this we strike a balance between task complexity and computational cost through strategic decisions, such as down-sampling or combining datasets.
 
+## Quick Start Guide
+Below is an example of how to use these benchmark datasets with the Huggingface `datasets` library:
+
+```python
+def find_variant_idx(examples):
+    """Find token location that differs between reference and variant sequence.
+
+    Args:
+        examples: (batch of) items from the dataset.
+    Returns:
+        dict with values index of difference.
+    """
+    idx = -1
+    for i, (ref, alt) in enumerate(zip(examples["ref_input_ids"], examples["alt_input_ids"])):
+        if ref != alt:
+            idx = i
+    rc_idx = -1
+    for i, (ref, alt) in enumerate(zip(examples["ref_rc_input_ids"], examples["alt_rc_input_ids"])):
+        if ref != alt:
+            rc_idx = i
+    return {"variant_idx": idx, "rc_variant_idx": rc_idx}
+
+dataset = dataset.map(find_variant_idx, desc="Find variant idx")
+```
+
 ## Dataset Tasks
 The Genomics LRB is a collection of tasks which can be loaded by passing in the corresponding `task_name` into the `load_dataset` function. All of the following datasets 
 allow the user to specify an arbitrarily long sequence length, giving more context to the task, by passing `sequence_length` kwarg to `load_dataset`. Additional task specific kwargs, if applicable,