Create a matrix with distances between geopoints

Question

I am struggling with the implementation of my idea to create the matrix of distances in km between EACH pair of stations in NJ Transit Rail. I have data for longitude and latitude of each stop,

And what I want to do is this table.

I already looked at some possible ways to achieve this table, but they are more for geometric coordinates rather than geographical. I would use the distance matrix but as I can see it is for another type of coordinates.

Help, please!

Can you attach actual data that can be copied and not an image? — NYC Coder, May 11 '20 at 19:15
Look at this question, it has all the details you need: [distance-matrix](https://stackoverflow.com/questions/29481485/creating-a-distance-matrix/45834105) — NYC Coder, May 11 '20 at 19:18
Can you be more specific about which part you’re struggling with? — AMC, May 11 '20 at 19:19

score 3 · Accepted Answer · edited Nov 10 '21 at 22:36

3

You are looking for geographical distance, i.e. Haversine distance. From sklearn 0.22.2, you can use haversine_distance:

x_deg = df[['stop_lat','stop_lon']].values
x_rad = np.deg2rad(x_deg)

# distances in miles
distances = haversine_distances(x_rad,x_rad) * 6371 / 1.6

pd.DataFrame(distances, 
             index=df.stop_name, columns=df.stop_name)

and you would get something like this:

stop_name         a         b         c
stop_name                              
a          0.000000  1.274556  1.396741
b          1.274556  0.000000  0.871521
c          1.396741  0.871521  0.000000

edited Nov 10 '21 at 22:36

halfer

19,824
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answered May 11 '20 at 19:22

Quang Hoang

146,074
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Thank you so much! – ZheniaMagic May 11 '20 at 19:28
One question. What are the metrics for the answers? km or miles? – ZheniaMagic May 11 '20 at 19:34
according to the linked doc, you need to multiply that with the Earth's radius to get the actual distance. so you can choose what you pleased. – Quang Hoang May 11 '20 at 19:39
Also see updated answer for conversion from degree to radian. – Quang Hoang May 11 '20 at 19:40
oh, okay, so if I multiply, which metric will it be? – ZheniaMagic May 11 '20 at 19:42

score 0 · Answer 2 · answered May 11 '20 at 19:22

You'd do it like this:

import pandas as pd
from scipy.spatial import distance_matrix

# You already have the data
data = [[5, 7], [7, 3], [8, 1]]
ctys = ['Boston', 'Phoenix', 'New York']

df = pd.DataFrame(data, columns=['xcord', 'ycord'], index=ctys)
df_mat = pd.DataFrame(distance_matrix(df.values, df.values), index=df.index, columns=df.index)
print(df_mat)

            Boston   Phoenix  New York
Boston    0.000000  4.472136  6.708204
Phoenix   4.472136  0.000000  2.236068
New York  6.708204  2.236068  0.000000

*but they are more for geometric coordinates rather than **geographical** * — Quang Hoang, May 11 '20 at 19:23

Create a matrix with distances between geopoints

2 Answers2