tracktable.render.map_processing.common_processing module

Module contents

tracktable.render.common_processing - Collection of functions that are commonly used across all of the rendering backends

tracktable.render.map_processing.common_processing.common_processing(trajectories, obj_ids, line_color, color_map, gradient_hue)

Common processing functionality

Parameters

• trajectories (list) – List of Trajectories

• obj_ids (list) – List of IDs

• string (hex color) – or matplotlib color object, or list of any of these): The single color to use for all the segments in each trajectory. Overrides color_map and gradient_hue values. Can be a list of matplotlib color name strings, hex color strings or matplotlib color objects the same length as the length of the list of trajectories.

• string – or matplotlib color object, or list of any of these): The single color to use for all the segments in each trajectory. Overrides color_map and gradient_hue values. Can be a list of matplotlib color name strings, hex color strings or matplotlib color objects the same length as the length of the list of trajectories.

• matplotlib (color_map (name of standard colormap as string or) – color_map object or list of either): The color map to use in rendering the segments of each trajectory.

• gradient_hue (float or list of floats) – hue or list of hues (one per trajectory) to be used in definig the gradient color map (dark to light) for the trajectories. Only used if line_color and color_map are not used (set to ‘’). If line_color, color_map and gradient_hue are all unset the default behavior is to set the gradient_hue based on a hash of the object_id

Returns

trajectories, line_color, color_map and gradient_hue

tracktable.render.map_processing.common_processing.draw_density_array(density, map_projection, bounding_box, colormap=None, colorscale=None, zorder=10, axes=None)

Render a histogram for the given map projection.

Parameters

• density (iterable) – Density array that will be drawn onto the map

• map_projection (Basemap) – Map to render onto

• bounding_box (point2d) – Bounding box of area to gdraw the

Keyword Arguments

• colormap (str or Colormap) – Colors to use for histogram (Default: None)

• colorscale (matplotlib.colors.Normalize or subclass) – Mapping from bin counts to color. Useful values are matplotlib.colors.Normalize() and matplotlib.colors.LogNorm(). (Default: None)

• zorder (int) – Image priority for rendering. Higher values will be rendered on top of actors with lower z-order. (Default: 10)

• axes (matplotlib.axes.Axes) – Axes to render into. Defaults to “current axes” as defined by Matplotlib. (Default:None)

Returns

The density rendered onto the map.

tracktable.render.map_processing.common_processing.hash_short_md5(string)

Given any string, returns a number between 0 and 1. The same

number is always returned given the same string. Internally uses hashlib.md5, but only uses the first quarter of the full hash

Parameters

string (str) – String to be hashed

Returns

0 or 1

tracktable.render.map_processing.common_processing.in_notebook()

Returns True if run within a Jupyter notebook, and false otherwise

tracktable.render.map_processing.common_processing.load_density_array(infile)

Load the density array from a file.

Parameters

infile (str) – Filename for input

Returns

The density array in the file.

tracktable.render.map_processing.common_processing.path_length_fraction_generator(trajectory)

Generator to produce path length fraction scalars A genertor that given a trajectory will generate a scalar for each point such that each scalar represents the fraction of the total length along the path at the associated point.

Parameters

trajectory (Trajectory) – The trajectory to use for generating scaler values

Returns

Fraction length scalar values for each point in the trajectory

tracktable.render.map_processing.common_processing.point_popup(current_point, point_popup_properties)

Formats the popup string for a point

Parameters

• current_point (point) – Current point of the trajectory

• point_popup_properties (list) – Point properties

Returns

String of point properties

tracktable.render.map_processing.common_processing.point_tooltip(current_point)

Formats the tooltip string for a point

Parameters

current_point (point) – Current point of the trajectory

Returns

Current points timestamp

tracktable.render.map_processing.common_processing.progress_linewidth_generator(trajectory)

Generator to produce progress linewidth scalars A generator that given a trajectory will generate a scalar for each point such that each scalar represents a good width value for the fraction of points that come before that point in the trajectory.

Parameters

trajectory (Trajectory) – The trajectory to use for generating scaler values

Returns

Linewidth scalar values for each point in the trajectory

tracktable.render.map_processing.common_processing.render_distance_geometry(backend, distance_geometry_depth, traj, map_canvas)

Renders the distance geometry calculations to the folium map

Parameters

• backend (str) – Backend to render with, either cartopy or folium

• distance_geometry_depth (int) – The depth of the distance geometry calculation

• traj (Trajectory) – The trajectory

• map_canvas (GeoAxes) – The canvas where distance geometry will be rendered

Returns

No return value

tracktable.render.map_processing.common_processing.render_line(backend, map_canvas, line_coords, control_color, weight, tooltip)

Renders a line onto a cartopy or folium map

Parameters

• backend (str) – Backend to use rendering into. Only supports ‘cartopy’ and ‘folium’

• map_canvas (GeoAxes) – The canvas where the line will be rendered

• line_coords (tuple) – Lon lat coordinates where to render the line

• control_color (float) – Color of the rendered line

• weight (int) – Linewidth

• tooltip (str) – Value to display for the line such as object_id

Returns

No return value

tracktable.render.map_processing.common_processing.save_density_array(density, outfile)

Save and output the density array to a file.

Parameters

• density (tuple) – Density to be saved to file

• outfile (str) – Filename to save output

Returns

No return value.

tracktable.render.map_processing.common_processing.sub_trajs_from_frac(trajectories, zoom_frac)

Create sub-trajectories from a given zoom fraction

Parameters

• trajectories (Trajectory) – Trajectories to create sub-trajectories from

• zoom_frac (list) – Fraction list to segment trajectories

Returns

sub_trajs