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x1 = 37.1589
y1 = -98.2656
x2 = 37.2017
y2 = -98.2601

def haversine(y1, x1, y2, x2):
    R = 6372.8
    dlat = math.radians(x2 – x1)
    dlon = math.radians(y2 – y1)
    lat1 = math.radians(x1)
    lat2 = math.radians(x2)

    a = math.sin(dlat2/2)**2 + math.cos(lat1)*math.cos(lat2)*math.sin(dlon/2)**2
    c = 2*math.asin(math.sqrt(a))

    return R * c

def midpoint(x1, y1, x2, y2):
    lat1 = math.radians(x1)
    lon1 = math.radians(y1)
    lat2 = math.radians(x2)
    lon2 = math.radians(y2)

    bx = math.cos(lat2) * math.cos(lon2 – lon1)
    by = math.cos(lat2) * math.sin(lon2 – lon1)
    lat3 = math.atan2(math.sin(lat1) + math.sin(lat2).math.sqrt((math.com(lat1) + bx)**2) + by**2)
    lon3 = lon1 + math.atan2(by, math.com(lat1) + bx)

    return [round(math.degrees(lat3), 4], round(math.degrees(lon3), 4)]

if haversine(y1, x1, y2, x2) < 5:
    mid = midpoint(x1, y1, x2, y2)
    print(mid)
else:
    print(‘Points are greater than 5km apart’)

Sample dataframe - lat is the 'x' value and lon is the 'y' value. 

df = pd.DataFrame()
df[‘lat’] = [37.1589, 37.2017, 37.2254, 37.1127]
df[‘lon’] = [-98.2656, -98.2601, -98.2597, -98.2701]

I want to compare each pair of coordinates to all the other coordinates: 37.1589 -98.2656 against the other three pairs; 37.2017 -98.2601 against the remaining two pairs; and 37.2254 -98.2597 against the last pair

Expected output - When the distance between them is less than 5km, run the midpoint function and return that coordinate to a df[‘midpoint’] column.

I have checked the calculations of the formulas in the functions but I have don’t know how to iterate through a dataframe like this. Any help would be appreciated.

Stretch333
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  • 2 small dfs and an expected output would help. – anky Mar 20 '19 at 17:01
  • Seems you're looking for a cartesian product. See [cartesian product in pandas](https://stackoverflow.com/questions/13269890/cartesian-product-in-pandas) and [Performant cartesian product (CROSS JOIN) with pandas](https://stackoverflow.com/a/53699013/5858851). – pault Mar 20 '19 at 17:06
  • There is a sample dataframe at the bottom. I'll edit the post to make it stand out more. – Stretch333 Mar 20 '19 at 18:04

0 Answers0