leiap.spatial

This file contains functions related to spatial data operations

Functions

find_geo_field(df, fields_shp_path)	Find the identifier for the field where the point or artifact lies geographically.
find_artifact_coords(artifacts, points[, …])	Add Easting and Northing to artifacts
read_fields_shp(path)	Load and clean up the Survey_Fields_Master.shp file
convert_coordinates(df[, x_col, y_col, …])	Transform coordinates from one system to another

leiap.spatial.find_geo_field(df, fields_shp_path)

Find the identifier for the field where the point or artifact lies geographically.

Parameters:

• df (pandas DataFrame) – Points or Artifacts DataFrame; must contain ‘Easting’ and ‘Northing’ columns
• fields_shp_path (str) – Path to the shapefile (.shp) containing the fields

Returns:

joined_df – Identical to the input points DataFrame with an added ‘geo_field’ column

Return type:

pandas DataFrame

Notes

leiap.spatial.find_artifact_coords(artifacts, points, join_col='SurveyPointId')

Add Easting and Northing to artifacts

Parameters:

• artifacts (pandas DataFrame) – DataFrame of artifact records
• points (pandas DataFrame) – DataFrame of points; must have ‘Easting’, ‘Northing’, and <join_col> columns
• join_col (str) – Column on which to join artifacts and points

Returns:

artifacts – Identical to artifacts input DataFrame with ‘Easting’, ‘Northing’ columns added

Return type:

pandas DataFrame

leiap.spatial.read_fields_shp(path)

Load and clean up the Survey_Fields_Master.shp file

Notes

Not meant to be a generic load function! Designed to work specifically with the file we have been using.

leiap.spatial.convert_coordinates(df, x_col='Easting', y_col='Northing', from_epsg='32631', to_epsg='3857')

Transform coordinates from one system to another

Parameters:

• df (pandas DataFrame) – Points or artifacts DataFrame with coordinate columns
• y_col (x_col,) – Columns with x- and y-coordinates
• to_epsg (from_epsg,) – EPSG coordinate system codes for the input and output coordinates

Returns:

df – Original DataFrame with new columns ‘x2’ and ‘y2’

Return type:

pandas DataFrame

Notes

Default behavior is to convert UTMs from Zone 31N to Web Mercator