This tutorial and notes cover visualising and calculating fundamental network analysis metrics through the NetworkX library in Python.
Live transport performance dashboards – a light example
Sydney bus performance dashboard
This shows an up-to-date overview of the current performance of the bus network in Sydney, queried every 15 minutes from the Transport for NSW Vehicles API. .
The infrastructure behind this is quite simple and powerful, and you can learn 90% of it through this tutorial.
Possible extensions
> Integrate real vs scheduled time
> Historic performance / animations throughout the day
Try:
> See the buses in the most congested traffic routes
> Query individual bus routes
> Analyse the occupancy of the bus network
> Scroll into individual areas to see changes in average km/h speed
> Summarise one of the above variables for the area within field of view
> Screenshot / compare different times of day
> Select one variable (such as ‘Standing Only’) and see the routes ranked by their count of this variable
Bus performance (last 15 minutes)
Creating spatial data analytics dashboards in Cartoframes
With the strength of Carto in terms of spatial science and location intelligence ; and the easy access to data science packages in Python, Carto’s new project ‘Cartoframes‘ has a lot of potential to provide excellent mapping dashboards for data-hungry workflows.
Below is a quick tutorial I have made which will hopefully help new users figure out how to use it. It is in no way comprehensive, and there are probably some pieces missing ; but it should be enough to go off to get started! The tutorial covers some of the elements of creating a ‘live’ weather data dashboard for New South Wales in Australia.
What is Cartoframes ? (from https://github.com/CartoDB/cartoframes)
A Python package for integrating CARTO maps, analysis, and data services into data science workflows.Python data analysis workflows often rely on the de facto standards pandas and Jupyter notebooks. Integrating CARTO into this workflow saves data scientists time and energy by not having to export datasets as files or retain multiple copies of the data. Instead, CARTOframes give the ability to communicate reproducible analysis while providing the ability to gain from CARTO’s services like hosted, dynamic or static maps and Data Observatory augmentation.
Features
Write pandas DataFrames to CARTO tables
Read CARTO tables and queries into pandas DataFrames
Create customizable, interactive CARTO maps in a Jupyter notebook
Interact with CARTO’s Data Observatory
Use CARTO’s spatially-enabled database for analysis
Step 1 – Install libraries
Install all of the relevant libraries. For me I’m using Canopy. Canopy provides Python 2.7 and 3.5, with easy installation and updates via a graphical package manager of over 450 pre-built and tested scientific and analytic Python packages from the Enthought Python Distribution. These include NumPy, Pandas, SciPy, matplotlib, scikit-learn, and Jupyter / IPython. You can get Canopy for free here.
Once installed, open the console and install the packages:
pip install cartoframes
pip install pandas
Step 2 – Import libraries
In a new Jupyter notebook, start by importing the libraries in the first block, these are the ones you’ll generally need (though you can go to town with other numerical / statistical packages here!):
import cartoframes
import pandas as pd
import numpy as np
Step 3 – Set up a Carto account and register for an API key
Start by going to Carto.com and signing up through the prompts.
Once you have signed up, in the top-right of your home page there should be setting toggle which show you:
View your public profile
Your account
Your API keys
Close session
Click on ‘Your API keys’ and copy what shows up on the next page. It should be a long string of text, looking something like this:
31b453f27c085747acc6a51a9e5717beae254ced
Step 4 – Connecting to your Carto account in Python
Try the following line of code in your next Jupyter code block, where xxxxxxxxxxxx is your new API key. This key allows Cartoframes to communicate directly with the data in your Carto account.
Where it says ‘oclock’ you should put your own username.
cc = cartoframes.CartoContext(base_url='https://oclock.carto.com',api_key='xxxxxxxxxxxx')
When you run this code and call ‘cc’ it should provide you with a message such as this:
cartoframes.context.CartoContext at 0x1ea3fa2c518
This means that cartoframes has successfully accessed your Carto account and you can call ‘cc’ to reference accessing this account from now on. Make sure you keep your API key safe!
Step 5 – Upload some data to Carto
For this task, I downloaded the shapefile components of weather locations from the Australian Bureau of Meteorology. This is all of the spatial files (.shp, shx, .dbf etc) for IDM 13 from:
ftp://ftp.bom.gov.au/anon/home/adfd/spatial/
These are all the files prefixed by IDM000013 and suffixed by .dbf,.prj,.sbn,.sbx,.shp,.shx,.shp.xml. Carto will need these all in a .zip file before you upload them.
The metadata for this dataset can be found here:
IDM00013 – point places (precis, fire, marine)
http://reg.bom.gov.au/catalogue/spatialdata.pdf
Once you have downloaded these you can upload the shapefile and it should give you a series of geolocated dots covering all of Australia, with many attributes as described in the metadata above. For this I called the dataset ‘idm00013’.
Step 6 – Read the data in jupyter
Let’s test if everything is working. The following should display a dataframe of all of the aspatial information stored in each weather location:
carto_df = cc.read('idm00013')
carto_df
The following should give you a list of all of the variables available to you to access and change:
list(carto_df.columns.values)
Step 7 – Making a map
Now for the exciting bit – creating a Carto map inside the Jupyter notebook.
Here I’ve picked the elevation column with a brown colour scheme, try:
from cartoframes import Layer, BaseMap, styling
cc.map(layers=[BaseMap('light'),Layer('idm00013',color={'column': 'elevation','scheme': styling.brwnYl(7)},size=5)],
interactive=True)
The following map should display, with light brown showing where the weather points are a low elevation, and high points shown in a darker brown.
Extension – Accessing and parsing a live data feed
The code below retrieves the latest weather forecasts for the weekend ahead from the Bureau of Meteorology’s API. It is stored in a dataframe ‘df’.
I’ll leave the indentation as part of this tutorial!
import xml.etree.ElementTree as ET
import csv
import pandas as pd
import urllib.request
req = urllib.request.Request('ftp://ftp.bom.gov.au/anon/gen/fwo/IDN11060.xml')
with urllib.request.urlopen(req) as response:
xml_data = response.read()
list_dict = []
root = ET.XML(xml_data)
for element in root.findall('forecast'):
for area in element:
for forecast in area:
min_temp = ''
max_temp = ''
aac_id = area.get('aac')
forecast_date = forecast.get('start-time-local')
for element in forecast:
if element.attrib['type'] == 'air_temperature_minimum':
min_temp = element.text
elif element.attrib['type'] == 'air_temperature_maximum':
max_temp = element.text
list_dict.append({'aac':aac_id, 'forecast_date':forecast_date, 'low_temp': min_temp, 'max_temp':max_temp})
df = pd.DataFrame(list_dict)
df
Extension Part 1 – Joining in a live data source
We now want to join the geographical data from the first exercise with this live data feed.
This is done with a ‘left’ join, so we keep all of the weather forecast records and add the geographic data to them.
merged_data = pd.merge(df,carto_df,on='aac')
merged_data
Extension Part 2 – Selecting some data
Now we filter out all records to get one particular day’s forecast (you will need to change the date here to current date).
The filtered data is then written to a new dataset in Carto called ‘merged_weathermap’.
one_forecast = merged_data[merged_data['forecast_date']=='2018-01-16T00:00:00+11:00']
cc.write(one_forecast, 'merged_weathermap',overwrite=True)
Extension Part 3 – Putting it all together
#Step 10
Now let’s add the data from the Weather feed API to a Cartoframes map. The following reads in the merged_weathermap dataset we just created and colours
in the maximum temperature for the forecast data for each weather point in New South Wales. Pink being a high temperature, and blue being a lower temperatue.
from cartoframes import Layer, BaseMap, styling
cc.map(layers=[BaseMap('light'),Layer('merged_weathermap',color={'column': 'max_temp','scheme': styling.tropic(10)},size=10)],
interactive=True)
—
That’s it! From here, it is feasible to see with a bit of extra work and some scripts that continuously ping the APIs etc that we are only a few steps away from creating live dashboards which integrate other statistical and mathematical packages, such as even including machine learning.
Looking forward to seeing developments in this space and if you have any feedback or ideas let me know!
For more information on Cartoframes have a look at their documentation.