Add dataset statistics and fix loading code

- Add row count (5,809,104)
- Add data splits table (train/valid/test counts)
- Add chromatin state class distribution (16 states)
- Fix repo_type="dataset" missing from hf_hub_download

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -10,10 +10,10 @@ size_categories:
 - 1M<n<10M
 ---
 
-# human-chromhmm-fullstack
+# human-chromhmm-fullstack-data
 
 ## Dataset Summary
-This dataset provides a multi-class annotation of genomic regions across the hg38 genome. It is derived from the ChromHMM fullstack annotation (Vu & Ernst, 2022; https://doi.org/10.1186/s13059-021-02572-z). Genomic regions are classified into 16 states. The data is derived from https://public.hoffman2.idre.ucla.edu/ernst/2K9RS//full_stack/full_stack_annotation_public_release/hg38/hg38_genome_100_segments.bed.gz.
+This dataset provides a multi-class annotation of genomic regions across the hg38 genome. It is derived from the ChromHMM fullstack annotation (Vu & Ernst, 2022; https://doi.org/10.1186/s13059-021-02572-z). Genomic regions are classified into 16 chromatin states. The data is derived from https://public.hoffman2.idre.ucla.edu/ernst/2K9RS//full_stack/full_stack_annotation_public_release/hg38/hg38_genome_100_segments.bed.gz.
 
 ## Repository Content
 1. `data.csv`: The main dataset stored in comma-separated tabular format.
@@ -21,15 +21,47 @@ This dataset provides a multi-class annotation of genomic regions across the hg3
 
 ## Dataset Structure
 
+- **Rows:** 5,809,104
+- **Columns:** 7
+
+### Data Splits
+| Split | Count |
+|-------|-------|
+| train | 5,042,325 |
+| valid | 364,387 |
+| test | 402,392 |
+
+### Chromatin States (16 classes)
+| State | Count |
+|-------|-------|
+| Quies | 1,485,576 |
+| Acet | 639,669 |
+| EnhA | 613,794 |
+| ReprPC | 610,147 |
+| Tx | 561,526 |
+| EnhWk | 543,113 |
+| HET | 521,161 |
+| TxWk | 254,518 |
+| TxEnh | 190,465 |
+| TxEx | 121,833 |
+| PromF | 88,429 |
+| GapArtf | 51,474 |
+| BivProm | 48,242 |
+| znf | 34,146 |
+| TSS | 24,402 |
+| DNase | 20,609 |
+
+### Column Descriptions
+
 | Column | Type | Description |
 | :--- | :--- | :--- |
 | chrom | string | Chromosome name (e.g., chr1) |
 | start | int | Start coordinate of the genomic interval |
 | end | int | End coordinate of the genomic interval |
-| state | string | Chromatin state annotation (e.g., EnhWk, Quies) |
+| state | string | Chromatin state annotation (16 classes) |
 | interval_idx | int | Unique numerical index for the specific genomic interval |
 | enformer_split | string | Overlap with the data splits used for training the Enformer model |
-| split | string |Splits used for downstream modeling (training/validation/test) |
+| split | string | Splits used for downstream modeling (train/valid/test) |
 
 ## Usage
 
@@ -38,9 +70,10 @@ import pandas as pd
 from huggingface_hub import hf_hub_download
 
 file_path = hf_hub_download(
-    repo_id="Genentech/human-chromhmm-fullstack-data", 
-    filename="data.csv"
+    repo_id="Genentech/human-chromhmm-fullstack-data",
+    filename="data.csv",
+    repo_type="dataset"
 )
 
 df = pd.read_csv(file_path)
-```
+```