diff --git a/opencellid_parsing/003c.convert_data_into_xy_center_at_00.py b/opencellid_parsing/003c.convert_data_into_xy_center_at_00.py
new file mode 100644
index 0000000..3d5faae
--- /dev/null
+++ b/opencellid_parsing/003c.convert_data_into_xy_center_at_00.py
@@ -0,0 +1,82 @@
+#!/usr/bin/python
+
+import os
+import sys
+import glob
+import pickle
+import numpy as np
+
+
+def convert_gps_into_xy(latlon1, latlon2, convert2radian=False):
+    radius = 6371e3
+    lat1, lon1 = latlon1
+    lat2, lon2 = latlon2
+    if convert2radian:
+        lat1 = lat1 * np.pi / 180
+        lat2 = lat2 * np.pi / 180
+        lon1 = lon1 * np.pi / 180
+        lon2 = lon2 * np.pi / 180
+    delta_lat = lat2 - lat1
+    delta_lon = lon2 - lon1
+    # a = np.sin(delta_lat / 2) ** 2 + np.cos(lat1) * np.cos(lat2) * np.sin(delta_lon / 2) ** 2
+    # c = 2 * np.arctan2(np.sqrt(a), np.sqrt(1 - a))
+    # d1meters = radius * c    # Haversine distance
+    x = delta_lon * np.cos((lat1 + lat2) / 2)
+    y = delta_lat
+    # d2meters = radius * np.sqrt(x*x + y*y) # Pythagorean distance
+    return x, y
+
+
+if len(sys.argv) < 3:
+    print('Usage: {} folderpath code_to_country_fp'.format(sys.argv[0]))
+    sys.exit(0)
+
+folderpath = sys.argv[1]
+code_to_country_fp = sys.argv[2]
+
+############################
+# load
+############################
+code_to_country = pickle.load(open(code_to_country_fp, 'rb'))
+
+############################
+# convert
+############################
+
+pickle_fp_with_groundtruth = '{}/with_groundtruth_converted.pickle'.format(folderpath)
+
+all_data = []
+for filepath in glob.glob("{}/with_groundtruth/*/*/*/*/*.csv".format(folderpath)):
+    __, __, radio, mcc, mnc, area, cell_and_loc = list(filter(None, filepath.rstrip('.csv').split('/')))
+    cell, cell_lon, cell_lat = cell_and_loc.split('_')
+    cell_lon = float(cell_lon)
+    cell_lon_rad = cell_lon * np.pi / 180
+    cell_lat = float(cell_lat)
+    cell_lat_rad = cell_lat * np.pi / 180
+    data = []
+    with open(filepath, 'r') as f:
+        lines = f.readlines()
+    for line in lines:
+        if '#' in line:
+            continue
+        tmp = line.rstrip().split(',')
+        lon = float(tmp[0])
+        lat = float(tmp[1])
+        sig = float(tmp[2])
+        x, y = convert_gps_into_xy((lat, lon), (cell_lat_rad, cell_lon_rad))
+        data.append([lon, lat, sig, x, y])
+    all_data.append({
+        'radio': radio,
+        'mcc': mcc,
+        'mnc': mnc,
+        'country_code': code_to_country.get('{}_{}'.format(mcc, mnc), 'unknown')[0],
+        'area': area,
+        'cell': cell,
+        'longitude': cell_lon,
+        'latitude': cell_lat,
+        'x': 0.0,
+        'y': 0.0,
+        'measurements': np.array(data)  # lon, lat, sig, x, y
+    })
+
+pickle.dump(all_data, open(pickle_fp_with_groundtruth, 'wb'))
diff --git a/opencellid_parsing/opencellid_with_groundtruth_num_distribution.png b/opencellid_parsing/opencellid_with_groundtruth_num_distribution.png
index a2e8118..0488626 100644
Binary files a/opencellid_parsing/opencellid_with_groundtruth_num_distribution.png and b/opencellid_parsing/opencellid_with_groundtruth_num_distribution.png differ
diff --git a/opencellid_parsing/opencellid_with_groundtruth_num_stat.png b/opencellid_parsing/opencellid_with_groundtruth_num_stat.png
index 9fb6ac7..bad966d 100644
Binary files a/opencellid_parsing/opencellid_with_groundtruth_num_stat.png and b/opencellid_parsing/opencellid_with_groundtruth_num_stat.png differ