''' Purpose: determine a rough estimate of the geocenter of the
        continental USA
'''

# get access to web-based data support
import url

# specify dataset web location
CSV_WEB_FOLDER = 'http://www.cs.virginia.edu/~cs1112/datasets/csv/'

USA_DATASET    = CSV_WEB_FOLDER + 'continental-usa.csv'

# get the dataset of interest
dataset = url.get_dataset( USA_DATASET )

# determine webfile header and location data
header    = dataset[ 0 ]
locations = dataset[ 1: ]

# determine geocenter
latitudes = []
longitudes = []
for row in locations:
    zipcode, town, state, latitude, longitude = row # split row into columns
    latitude = float( latitude ) # Take columns that are interesting and convert them into the right data type
    longitude = float( longitude )
    latitudes.append( latitude ) # Accumulate the latitudes and longitudes
    longitudes.append( longitude )

latitudes = sorted( latitudes )
longitudes = sorted( longitudes )

num_of_locations = len( locations )

middle = num_of_locations // 2
mid_lat = latitudes[ middle ]
mid_long = longitudes[ middle ]
print( "mid_lat", mid_lat, "mid_long", mid_long )

first_lat = latitudes[ 0 ]
last_lat = latitudes[ num_of_locations - 1 ] # index of the last thing in the list is (size of list) - 1
new_mid_lat = ( first_lat + last_lat ) / 2

first_long = longitudes[ 0 ]
last_long = longitudes[ num_of_locations - 1 ]
new_mid_long = ( first_long + last_long ) / 2

print( "new_mid_lat", new_mid_lat, "new_mid_long", new_mid_long ) # This was the right way to do it