voxcity.geoprocessor.draw.rectangle

Interactive rectangle drawing and rotation utilities for geographic maps.

Provides functions for: - Drawing rectangles on interactive ipyleaflet maps - Rotating rectangles with proper coordinate transformations - City-centered map initialization with rectangle drawing - Fixed-dimension rectangle creation from center points

Functions

rotate_rectangle(m, rectangle_vertices, angle)	Project rectangle to Mercator, rotate, and re-project to lat-lon coordinates.
draw_rectangle_map([center, zoom])	Create an interactive map for drawing rectangles with two modes.
draw_rectangle_map_cityname(cityname[, zoom])	Create an interactive map centered on a specified city for drawing rectangles.
center_location_map_cityname(cityname, ...[, zoom, ...])	Create a map centered on a city where clicking creates a rectangle of specified dimensions.
rectangle_map([center, zoom, width, height, cityname])	Create an interactive map with a side panel for drawing rectangles.
create_rectangle_map([cityname, zoom, width, height])	Create an interactive rectangle-drawing map with a side panel.

Module Contents

voxcity.geoprocessor.draw.rectangle.rotate_rectangle(m, rectangle_vertices, angle)

Project rectangle to Mercator, rotate, and re-project to lat-lon coordinates.

The rotation is performed around the rectangle’s centroid using a standard 2D rotation matrix in Web Mercator space for accurate distance preservation.

Parameters:

• m (ipyleaflet.Map) – Map object to draw the rotated rectangle on.

• rectangle_vertices (list) – List of (lon, lat) tuples defining the rectangle.

• angle (float) – Rotation angle in degrees (positive = counter-clockwise).

Returns:

Rotated (lon, lat) tuples, or None if no vertices provided.

Return type:

list

voxcity.geoprocessor.draw.rectangle.draw_rectangle_map(center=(40, -100), zoom=4)

Create an interactive map for drawing rectangles with two modes.

• Aligned mode: click two opposite corners to draw an axis-aligned rectangle.

• Rotated mode: click 3 points to draw a rotated rectangle.

Drawing starts immediately when a mode button is selected.

Parameters:

• center (tuple) – Center coordinates (lat, lon). Defaults to (40, -100).

• zoom (int) – Initial zoom level. Defaults to 4.

Returns:

(ipywidgets.VBox, list that will be populated with (lon, lat) vertices)

Return type:

tuple

voxcity.geoprocessor.draw.rectangle.draw_rectangle_map_cityname(cityname, zoom=15)

Create an interactive map centered on a specified city for drawing rectangles.

Two modes are available via toggle buttons:

• Aligned: click two opposite corners (axis-aligned rectangle).

• Rotated: click 3 points to draw a rotated rectangle.

Parameters:

• cityname (str) – Name of the city (e.g. “Tokyo, Japan”).

• zoom (int) – Initial zoom level. Defaults to 15.

Returns:

(ipywidgets.VBox, list that will be populated with (lon, lat) vertices)

Return type:

tuple

voxcity.geoprocessor.draw.rectangle.center_location_map_cityname(cityname, east_west_length, north_south_length, zoom=15, rotation_angle=0)

Create a map centered on a city where clicking creates a rectangle of specified dimensions.

After placing a center point, an interactive rotation slider appears so the rectangle can be rotated on the map in real time.

Parameters:

• cityname (str) – Name of the city.

• east_west_length (float) – Width of the rectangle in meters.

• north_south_length (float) – Height of the rectangle in meters.

• zoom (int) – Initial zoom level. Defaults to 15.

• rotation_angle (float) – Initial rotation angle in degrees (positive = counter-clockwise). Defaults to 0.

Returns:

(widget, list that will be populated with (lon, lat) vertices)

widget is an ipywidgets VBox containing the map and a rotation slider. Display it with display(widget) or as the last expression in a notebook cell.

Return type:

tuple

voxcity.geoprocessor.draw.rectangle.rectangle_map(center=(40, -100), zoom=15, width=500, height=500, cityname='')

Create an interactive map with a side panel for drawing rectangles.

Three drawing modes are provided via the panel:

• Aligned: click two opposite corners for an axis-aligned rectangle.

• Rotated: click 3 points to draw a rotated rectangle.

• Fixed: click a center point to place a rectangle with the specified width (east-west) and height (north-south), then adjust the rotation angle with a slider.

The panel includes a city-name field that re-centres the map on submission.

Parameters:

• center (tuple) – Map center as (lat, lon). Defaults to (40, -100).

• zoom (int) – Initial zoom level. Defaults to 15.

• width (float) – Initial east-west length in metres (for Fixed mode).

• height (float) – Initial north-south length in metres (for Fixed mode).

• cityname (str) – Pre-filled city name for the location field.

Returns:

(ipywidgets.VBox, list that will be populated with (lon, lat) vertices)

Return type:

tuple

voxcity.geoprocessor.draw.rectangle.create_rectangle_map(cityname=None, zoom=15, width=500, height=500)

Create an interactive rectangle-drawing map with a side panel.

Combines aligned / rotated drawing and fixed-dimension placement into a single map. If cityname is provided the map is centred on that city and the location field is pre-filled; otherwise a world-level view is shown and the user can type a city name into the panel.

Parameters:

• cityname (str, optional) – Name of the city (e.g. "Tokyo").

• zoom (int) – Initial zoom level. Defaults to 15.

• width (float) – Initial east-west length in metres (for Fixed mode).

• height (float) – Initial north-south length in metres (for Fixed mode).

Returns:

(ipywidgets.VBox, list that will be populated with (lon, lat)

vertices in SW → NW → NE → SE order)

Return type:

tuple