Address rounding differences in bee_waggle_6

To construct this timeseries from the original data
we compute the sine and cosine of the head angle
of the bee. On different systems this can result in
slight differences in the data due to rounding. This
commit adds a known version of the dataset with a
different rounding than the original one and adds
a comment to the user when the checksum is not matched
exactly.

1 files changed, 34 insertions, 11 deletions

diff --git a/datasets/bee_waggle_6/get_bee_waggle_6.py b/datasets/bee_waggle_6/get_bee_waggle_6.py
index 6f80042..1a2033b 100644
--- a/datasets/bee_waggle_6/get_bee_waggle_6.py
+++ b/datasets/bee_waggle_6/get_bee_waggle_6.py
@@ -18,6 +18,7 @@ import json
 import math
 import os
 import zipfile
+import sys
 
 from functools import wraps
 from urllib.request import urlretrieve
@@ -26,8 +27,11 @@ ZIP_URL = "https://web.archive.org/web/20191114130815if_/https://www.cc.gatech.e
 
 MD5_ZIP = "039843dc15c72fd5450eeb11c6e5599c"
 MD5_JSON = "4f03feafecb3be0b069b3cb0d6b17d4f"
-# alternative checksum for small rounding errors
-MD5_JSON_2 = "71311783488ee5f1122545d24c15429b"
+# known alternative checksums for small rounding errors
+MD5_JSON_X = [
+    "71311783488ee5f1122545d24c15429b",
+    "3632e004b540de5c3eb049fb5591d044",
+]
 
 NAME_ZIP = "psslds.zip"
 NAME_JSON = "bee_waggle_6.json"
@@ -50,7 +54,7 @@ def check_md5sum(filename, checksum):
     return h == checksum
 
 
-def validate(checksum, alternative_checksum=None):
+def validate(checksum, alt_checksums=None):
     """Decorator that validates the target file."""
 
     def validate_decorator(func):
@@ -61,18 +65,37 @@ def validate(checksum, alternative_checksum=None):
                 return
             if (
                 os.path.exists(target)
-                and alternative_checksum
-                and check_md5sum(target, alternative_checksum)
+                and alt_checksums
+                and any(check_md5sum(target, c) for c in alt_checksums)
             ):
+                print(
+                    "Note: Matched alternative checksum for %s. "
+                    "This indicates that small differences exist compared to "
+                    "the original version of this time series, likely due to "
+                    "rounding differences. Usually this is nothing to "
+                    "worry about." % target,
+                    file=sys.stderr,
+                )
                 return
             out = func(*args, **kwargs)
             if not os.path.exists(target):
                 raise FileNotFoundError("Target file expected at: %s" % target)
-            if not (check_md5sum(target, checksum) or (
-                alternative_checksum
-                and check_md5sum(target, alternative_checksum)
-            )):
-                raise ValidationError(target)
+            if not (
+                check_md5sum(target, checksum)
+                or (
+                    alt_checksums
+                    and any(check_md5sum(target, c) for c in alt_checksums)
+                )
+            ):
+                print(
+                    "Warning: Generated dataset %s didn't match a "
+                    "known checksum. This is likely due to "
+                    "rounding differences caused by "
+                    "different system architectures. Minor differences in "
+                    "algorithm performance can occur for this dataset. "
+                    % target,
+                    file=sys.stderr,
+                )
             return out
 
         return wrapper
@@ -85,7 +108,7 @@ def download_zip(target_path=None):
     urlretrieve(ZIP_URL, target_path)
 
 
-@validate(MD5_JSON, MD5_JSON_2)
+@validate(MD5_JSON, MD5_JSON_X)
 def write_json(zip_path, target_path=None):
     with zipfile.ZipFile(zip_path) as thezip:
         with thezip.open("psslds/zips/data/sequence6/btf/ximage.btf") as fp: