rohitsinghsalyan / polygeohasher

A complete package to work with polygons and geohashes. Optimisation of Geohash levels to cover and area with % error controlled by user. Also allows to convert geohases to polygons.

polygeohasher

polygeohasher is a python package to implement polygon to geohash and vice versa with optimisation of geohash levels as per the user requirement, with error rate being controlled by the user.

Installation

Use the package manager pip to install polygeohasher.

pip3 install polygeohasher

Poetry: Add package to lock file

poetry add polygeohasher

Usage

from polygeohasher import polygeohasher
import geopandas as gpd

# read geojson(geometry) file
gdf = gpd.read_file("your geospatial file format") # read your geometry file here

# initialize polygeohasher
pgh = polygeohasher.Polygeohasher(gdf)

# declare geohash levels
INPUT_GEOHASH_LEVEL = 6
MINIMUM_GEOHASH_LEVEL = 5
MAXIMUM_GEOHASH_LEVEL = 7

# create a dataframe with list of geohashes for each geometry
initial_df = pgh.create_geohash_list(INPUT_GEOHASH_LEVEL,inner=False)

# get a dataframe with optimized list of geohashes
final_df = pgh.geohash_optimizer(initial_df, MINIMUM_GEOHASH_LEVEL, MAXIMUM_GEOHASH_LEVEL, INPUT_GEOHASH_LEVEL) 

# prints optimization summary
pgh.optimization_summary(initial_df, final_df)

# convert geohash to geometry
geo_df = pgh.geohashes_to_geometry(final_df, "geohash_column_name")

# write file in desired spatial file format
geo_df.to_file("your write path.format",driver = "GeoJSON") 

Following is the optimization summary:

--------------------------------------------------
            OPTIMIZATION SUMMARY
--------------------------------------------------
Total Counts of Initial Geohashes :  2597
Total Counts of Final Geohashes   :  837
Percent of optimization           :  67.77 %
--------------------------------------------------

Some visualisations

Study are consist of division of City of Bengaluru in India.

Primary Output of geohashes without any optimisation.

Final Output of geohashes with optimization of number of geohashes at different levels to cover an area.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

Apache License, Version 2.0

polygeohasher's Issues

Question on optimization

Hi hi,

Thank you for this great library.

I'm curious if you have thought of using a "fill" method over the reduce method being used for the creattion of optimized list of geohashes?

I ask because the current approach can be very time consuming and I wonder if the other-way-around would speed things up.

All the best,

• Stefán

Various spelling mistakes in code....

Just tried this repo. Works well, except for the following:

When trying the example, was getting a key error when attempting to create the geohash geometry dataframe (geo_df = ...).

Error was traced to misspelling of "opitimized_geohash_list", which should be "optimized_geohash_list"

Also, for consistency's sake, would stick with "optimize..." throughout the codebase rather than intermingle "optimize..." and "optimise.."

Best,

Mike

Tests are missing

The readme mentions to make sure to include tests for proposed changes, sadly the project does not come with any as of right now. It seems the test directory is excluded in the .gitignore file. Can those be added to the project?

Geohash column name

Hi,

May I know what would be the appropriate data type for the geohash column name in my geojson file? Currently using string as the data type for my column, I am receiving the error in the photo attached.

Thank you.