Functions¶
Helper functions¶
These functions are used for quickly checking properties of a table or the server.
Wrapper functions¶
These functions work as shortcuts to build indicators.
-
brix.make_numeric_indicator(name, return_indicator, viz_type='bar', requires_geometry=False, requires_geogrid_props=False)[source]¶ Function that constructs an indicator based on a user defined return_indicator function.
- Parameters
name (str) – Name of the indicator.
return_indicator (func) – Function that takes in geogrid_data and return the value of the indicator.
viz_type (str, defaults to 'bar') – Visualization type in front end. Used for numeric indicators.
requires_geometry (boolean, defaults to False) – If True, the geogrid_data object will also come with geometries.
requires_geogrid_props (boolean, defaults to False) – If True, the geogrid_data object will include properties.
- Returns
I – Numeric indicator that returns the value of the given function.
- Return type
-
brix.make_static_heatmap_indicator(shapefile, columns=None, name=None)[source]¶ Function that constructs a heatmap indicator that only visualizes the given shapefile. This function wraps
brix.StaticHeatmapto make it easier for users to find.- Parameters
shapefile (geopandas.GeoDataFrame or str) – Shapefile with values for each point, or path to shapefile.
columns (list) – Columns to plot. If not provided, it will return all numeric columns. The name of the indicator will be given by the name of the column.
name (str, optional) – Name of the indicator. If not provided, it will generate a name by hashing the column names.
- Returns
Heatmap – Heatmap indicator that posts the given shapefile to the table.
- Return type
-
brix.griddify(geogrid_data, shapefile, extend_grid=True, buffer_percent=1.3, columns=None, local_crs=None)[source]¶ From a shapefile with polygons and properties, it creates a shapefile with points and the properties of the polygons they fall in. Points are taken from the given GEOGRID and the grid is extended to incorporate a buffer. Points are in the center of the grid.
- Parameters
geogrid_data (brix.GEOGRIDDATA) –
shapefile (geopandas.GeoDataFrame) – Shapefile in WGS84 (default) or in local_crs (if local_crs is provided)
extend_grid (boolean, defaults to True) – If False, it will only return the values for the centroids of the grid.
buffer_percent (float, defaults to 1.3) – Buffer to extend the grid by (in units of grid diameter).
columns (list, defaults to all numeric) – Columns to select besides geometry. If not provided, it will default to all numeric columns.
local_crs (str, defaults to wgs84) – ESRI code for local CRS, must match crs of shapefile. Recommended: Calculating the centroids of each cell will be more precise if this is provided.
- Returns
joined – Shapefile of points and their values.
- Return type
geopandas.GeoDataFrame
OSM functions¶
These functions help you get data from Open Street Maps for your table.
-
brix.get_OSM_geometries(H, tags={'building': True}, buffer_percent=0.25, use_stored=True, only_polygons=True)[source]¶ Gets the buildings from OSM within the table’s geogrid. This function requires osmnx package to be installed. Simple usage: buildings = OSM_geometries(H).
- Parameters
H (
brix.Handler) – Table Handler.tags (dict, defaults to building) – Tags of geometries to get. See: osmnx.geometries_from_polygon
buffer_percent (float, defaults to 0.25) – Buffer to use around the table. Size of buffer in units of the grid diameter See
brix.get_buffer_size().use_stored (boolean, defaults to True) – If True, the function will retrieve the results once and save them in the Handler under the
brix.Handler.OSM_dataattribute. If False, the function will retrieve the results every time it is called.only_polygons (boolean, defaults to True) – If False, it will return all buildings, including those without their polygon shape (e..g some buildings just have a point).
- Returns
buildings – Table with geometries from OSM.
- Return type
geopandas.GeoDataFrame
-
brix.get_OSM_nodes(H, expand_tags=False, amenity_tag_categories=None, use_stored=True, buffer_percent=0.25, quietly=True)[source]¶ Returns the nodes from OSM. This function can be used to obtain a list of amenities within the area defined by the table. There is a default buffer added around the grid, but you can increase this by changing buffer_percent.
- Parameters
H (
brix.Handler) – Table Handler.expand_tags (boolean, defaults to False.) – If True, it will expand all the tags into a wide format with one column per tag. Columns will be named as: tag_{tag}
amenity_tag_categories (dict (optional)) –
Dictionary with categories of amenities. For example:
- {
- “restaurants”: {
“amenity”:[“restaurant”,”cafe”,”fast_food”,”pub”,”cafe”], “shop”:[“coffee”]
}, “nightlife”: {
”amenity”:[“bar”,”pub”,”biergarten”,”nightclub”]
}
}
Will add two new columns: “category_restaurants” and “category_nightlife”
use_stored (boolean, defaults to True) – If True, the function will retrieve the results once and save them in the Handler under the
brix.Handler.OSM_dataattribute. If False, the function will retrieve the results every time it is called.buffer_percent (float, defaults to 0.25) – Buffer to use around the table. Size of buffer in units of the grid diameter See get_buffer_size.
quietly (boolean, defaults to False) – If True, it will print the generated URL
- Returns
node_data_df – Table with all the nodes within the bounds.
- Return type
geopandas.GeoDataFrame
-
brix.OSM_infer_geogrid_data(H, amenity_tag_categories=None)[source]¶ Infers the cell type based on the OSM tags classified into categories in amenity_tag_categories. This function does not update the color of the cell, as
brix.Handler.post_geogrid_data()will eventually take care of this.- Parameters
H (
brix.Handler) – Handler for the table to infer types for.amenity_tag_categories (dict) –
Dictionary with categories of amenities. For example:
- {
- “restaurants”: {
“amenity”:[“restaurant”,”cafe”,”fast_food”,”pub”,”cafe”], “shop”:[“coffee”]
}, “nightlife”: {
”amenity”:[“bar”,”pub”,”biergarten”,”nightclub”]
}
}
Will add two new columns: “category_restaurants” and “category_nightlife”
- Returns
geogrid_data – List of cells to be updated.
- Return type
list