Is there any way to access the matrixes using the (x,y) as index

Question

I want to generate a matrix that stores the distance between every point with every other point. I want to be able to access this distance value in the matrix using the two coordinates.

As in the image below, I want to be able to access the distance using the points as the index.

matrix[point a, point b] = distance between two points

Answer 1

One solution is to use the pandas module.

• You can define column and index name with "points coordinates".
• Fill the data using the scipy.spatial.distance.cdist
• Access all the distances from one point using df["[x, y]"]
• Access a specific distance using iloc on a column

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Full code + illustration

# import modules
import pandas as pd
from scipy.spatial.distance import cdist

# input points
points = [[1, 2], [2, 3], [3, 4], [5, 6], [9, 10]]

# Create dataframe
df = pd.DataFrame(cdist(points, points),
     columns=[str(p) for p in points],
     index=[str(p) for p in points])
print(df)
#             [1, 2]    [2, 3]    [3, 4]    [5, 6]    [9, 10]
# [1, 2]    0.000000  1.414214  2.828427  5.656854  11.313708
# [2, 3]    1.414214  0.000000  1.414214  4.242641   9.899495
# [3, 4]    2.828427  1.414214  0.000000  2.828427   8.485281
# [5, 6]    5.656854  4.242641  2.828427  0.000000   5.656854
# [9, 10]  11.313708  9.899495  8.485281  5.656854   0.000000

# select column "[2, 3]"
print(df["[2, 3]"])
# [1, 2]     1.414214
# [2, 3]     0.000000
# [3, 4]     1.414214
# [5, 6]     4.242641
# [9, 10]    9.899495

# get distance between point [2 3] and [1 2]
print(df["[2, 3]"].loc["[1, 2]"])
# 1.4142135623730951

Hope that helps