#!/usr/bin/env python
# coding: utf-8

# # Computing movement speed
# 
# <img align="right" src="https://movingpandas.github.io/movingpandas/assets/img/movingpandas.png">
# 
# [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/movingpandas/movingpandas-examples/main?filepath=1-tutorials/2-computing-speed.ipynb)
# [![IPYNB](https://img.shields.io/badge/view-ipynb-hotpink)](https://github.com/movingpandas/movingpandas-examples/blob/main/1-tutorials/2-computing-speed.ipynb)
# [![HTML](https://img.shields.io/badge/view-html-green)](https://movingpandas.github.io/movingpandas-website/1-tutorials/2-computing-speed.html)
# 
# MovingPandas offers functions to compute and/or visualize the speed of movement along the trajectory between consecutive points.

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import pandas as pd
import geopandas as gpd
import movingpandas as mpd
import shapely as shp
import hvplot.pandas 

from geopandas import GeoDataFrame, read_file
from shapely.geometry import Point, LineString, Polygon
from datetime import datetime, timedelta
from holoviews import opts

import warnings
warnings.filterwarnings('ignore')

opts.defaults(opts.Overlay(active_tools=['wheel_zoom'], frame_width=500, frame_height=400))

mpd.show_versions()


# ## Basic example

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df = pd.DataFrame([
  {'geometry':Point(0,0), 't':datetime(2018,1,1,12,0,0)},
  {'geometry':Point(6,0), 't':datetime(2018,1,1,12,0,6)},
  {'geometry':Point(6,6), 't':datetime(2018,1,1,12,0,11)},
  {'geometry':Point(9,9), 't':datetime(2018,1,1,12,0,14)}
]).set_index('t')
gdf = GeoDataFrame(df, crs=31256)
toy_traj = mpd.Trajectory(gdf, 1)
toy_traj


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toy_traj.add_speed(overwrite=True)
toy_traj.df


# We can also visualize the speed values:

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toy_traj.plot(column="speed", linewidth=5, capstyle='round', legend=True)


# Similar to speed, we can also add other columns:

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toy_traj.add_direction(overwrite=True)
toy_traj.df


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toy_traj.add_timedelta(overwrite=True)
toy_traj.df


# We can also use custom units for distance, speed, and acceleration. Allowed units include metric units from mm to km, imperial units from inch to mile, nautical miles, and non-standard units which are used as CRS distance units e.g. US Survey units.

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toy_traj.add_distance(overwrite=True, name="distance (km)", units="km")
toy_traj.add_distance(overwrite=True, name="distance (yards)", units="yd")
toy_traj.add_speed(overwrite=True, name="speed (ft/min)", units=("ft", "min"))
toy_traj.add_speed(overwrite=True, name="speed (knots)", units=("nm", "h"))
toy_traj.add_acceleration(overwrite=True, name="acceleration (mph/s)", units=("mi", "h", "s"))
toy_traj.df


# ## Real-world trajectories

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gdf = read_file('../data/geolife_small.gpkg')
tc = mpd.TrajectoryCollection(gdf, 'trajectory_id', t='t')


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my_traj = tc.trajectories[1]


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my_traj.df


# Even if the ``Trajectory``/``TrajectoryCollection`` GeoDataFrame does not contain a speed column, we can still plot movement speed:

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my_traj.plot(column='speed', linewidth=5, capstyle='round', figsize=(9,3), legend=True, vmax=20)


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my_traj.hvplot(c='speed', clim=(0,20), line_width=7.0, tiles='CartoLight', cmap='Viridis', colorbar=True)


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tc.plot(column='speed', linewidth=5, capstyle='round', legend=True, vmax=20)


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