Create-sector-shape-KML-file

Create sector shape KML layer from given pandas dataframe.

Overview

Creating polygons with complex geometries is not a simple while working with KML format. Therefore, in order to create the shape of the sector, we must use the mathematical parameters that will allow us to calculate the shape.

Therefore, the input dataframe must include the following parameters:

• X & Y coordinates, in wgs84 geo dd format
• Main angle of the sector in relation to the north, in degrees (angle parameter)
• Length of the desired sector, in meters (distance parameter)
• Angle size of the sector, in degrees (std parameter)

Using this data you can calculate the sector shape, according to the following figure:

Also, another parameter defined by default in the code is the arc-resolution of the sector (points parameter).The default value of this variable is points=36.

In order to perform the calculation, we must first perform the conversion of the coordinates to the UTM format. This format will allow to calculated the sector by precise meters terms. Also, after calculating the points that composed the sector, the code convert them back to wgs84 geo dd format, so that it allow to save them later as a KML file.

As part of this conversion, the code also perform automatic calculation of the utm zone, And we will check whether the coordinates are located in the northern ("U") or southern ("D") part of the Earth. This information will be used by the code in converting the data back to wgs84 geo dd format.

As part of the calculation, the code calculated mathematically the position of the points composed the arc of the sector. The direction of the sector converted from degrees to radians, and using with the length to calculated the points that composed the arc. Every point calculated relatively the origin coordinates. It is important to note that the angles on which the calculation is made, assume that an angle of 0 degrees is oriented to the north, as can be seen in the figure:

All the points that composed the sector shape are saved as a list of X and Y coordinates. This data is entered into the original dataframe as "POLYGON" field. If "output" variable defined, the code code will create the new KML layer using the simplekml library.

An example of one of the KML layers created using the code can be seen in the New York Harbor area:

All the layers created in the examples of this project uploaded to this MyMaps link: sector_maps

Libraries

The code uses the following libraries in Python:

utm

numpy

simplekml

pandas

Application

An application of the code is attached to this page under the name:

"implementation.py"

the examples outputs are also attached here.

Example for using the code

To use this code, you just need to import it as follows:

# import
from sector_creator import create_sector_kml
import pandas as pd

# define variables
data = pd.read_csv(r'path\file.csv')
name = 'name'
x_field = 'x'
y_field = 'y'
angle = 'angle'
distance = 'distance'
std = 'sd'

# application
create_sector_kml(data,x_field,y_field,angle,distance,std,name='name', points=50,output='POLYGONS_FILE')

When the variables displayed are:

data: the given pandas dataframe

x_field: x coordiantes field name

y_field: y coordiantes field name

angle: sector main angle field name

distance: distance of the the arc from the origin point field name

std: sector angle size field name

points: the arc resolution (default: 36)

name: row name field name (default: None)

output: name of the output kml file (default: None)

License

MIT © Etzion Harari