From 73e7d239dc885990be1e8c7d27d239e32bfad45e Mon Sep 17 00:00:00 2001
From: madrigal <madrigal@qoherent.ai>
Date: Wed, 17 Sep 2025 23:16:17 -0400
Subject: [PATCH] Fixed longitude parsing, added fixer functions

---
 helper_functions.py | 70 +++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 68 insertions(+), 2 deletions(-)

diff --git a/helper_functions.py b/helper_functions.py
index 4228392..d437591 100644
--- a/helper_functions.py
+++ b/helper_functions.py
@@ -83,9 +83,19 @@ def parse_lat_lon(value: str, direction: str) -> float:
     """
     if not value or not direction:
         return None
-    degrees = int(value[:2])
-    minutes = float(value[2:])
+
+    # Latitude has 2° digits, longitude has 3° digits
+    if direction in ["N", "S"]:
+        deg_len = 2
+    elif direction in ["E", "W"]:
+        deg_len = 3
+    else:
+        return None  # Invalid direction
+
+    degrees = int(value[:deg_len])
+    minutes = float(value[deg_len:])
     decimal = degrees + minutes / 60
+
     if direction in ["S", "W"]:
         decimal = -decimal
     return decimal
@@ -119,3 +129,59 @@ def save_data_to_json(data, filename):
             json.dump(existing_data, file, indent=4)
     except Exception as e:
         print(f"Error saving data to JSON: {e}")
+
+
+def fix_long(bad_long):
+    """
+    Fix longitude values incorrectly parsed from NMEA (leading zero dropped degrees).
+    
+    Assumes all values should be around -79.x based on recording location.
+    Removes the spurious leading digit from minutes.
+    """
+    broken_degrees = 7
+    # Recover "minutes" from the broken decimal
+    extended_minutes = (abs(bad_long) - broken_degrees) * 60
+
+    # Remove the extra leading digit (e.g. 920 -> 20)
+    minutes = extended_minutes % 100
+
+    corrected_degrees = 79
+    decimal = corrected_degrees + minutes / 60
+
+    if bad_long < 0:
+        decimal = -decimal
+
+    return decimal
+
+
+def add_distance_after(filename: str, base_location: dict):
+    try:
+        with open(filename, "r") as file:
+            data = json.load(file)
+    except FileNotFoundError:
+        print('No file by that name')
+        return None
+    
+    distance = 'Unknown'
+    
+    for dictionary in data:
+        if 'latitude' in dictionary:
+            # dictionary['longitude'] = fix_long(dictionary['longitude'])
+            distance = calculate_distance(base_location, dictionary)
+            dictionary["distance"] = distance
+        elif 'iperf_full' in dictionary:
+            dictionary['start_distance'] = distance
+
+    # Save updated data back to the file
+    with open(filename, "w") as file:
+        json.dump(data, file, indent=4)
+
+
+if __name__ == "__main__":
+    filename = '/home/madrigal/repos/range-testing/data/boat_relay_sept_17/test_1758123903_copy.json'
+    base_location = {
+        'latitude': 43.656328,
+        'longitude': -79.307884,
+        'altitude': 80,
+    }
+    add_distance_after(filename=filename, base_location=base_location)