Data-Analysis-Jupyter/datashader-work/datashader-examples

Datashader Examples

The best way to understand how Datashader works is to try out our extensive set of examples. Datashader.org includes static versions of the getting started guide, user manual, and topic examples, but for the full experience with dynamic updating you will need to install them on a live server.

These instructions assume you are using conda, but they can be adapted as needed to use pip and virtualenv if desired.

To get started, first go to your home directory and download the current list of everything needed for the examples:

• Download the conda ds environment file and save it as environment.yml.

Then run the following commands in your terminal (command) prompt, from wherever you saved environment.yml:

1. conda env create --file environment.yml
2. conda activate ds
3. datashader examples
3. cd datashader-examples

Step 1 will read environment.yml, create a new Conda environment named ds, and install of the libraries needed into that environment (including datashader itself). It will use Python 3.6 by default, but you can edit that file to specify a different Python version if you prefer (which may require changing some of the dependencies in some cases).

Step 2 will activate the ds environment, using it for all subsequent commands. You will need to re-run step 2 after closing your terminal or rebooting your machine, if you want to use anything in the ds environment. For older versions of conda, you may instead need to do source activate ds (mac/linux) or activate ds (windows).

Step 3 will copy the datashader examples from wherever Conda placed them into a subdirectory datashader-examples, and will then download the sample data required for the examples. (datashader examples is a shorthand for datashader copy-examples --path datashader-examples && datashader fetch-data --path datashader-examples.)

The total download size is currently about 4GB to transfer, requiring about 10GB on disk when unpacked, which can take some time depending on the speed of your connection. The files involved are specified in the text file datasets.yml in the datashader-examples directory, and you are welcome to edit that file or to download the individual files specified therein manually if you prefer, as long as you put them into a subdirectory data/ so the examples can find them. Once these steps have completed, you will be ready to run any of the examples listed on datashader.org.

Notebooks

Most of the examples are in the form of runnable Jupyter notebooks. Once you have obtained the notebooks and the data they require, you can run them on your own system using Jupyter:

cd datashader-examples
jupyter notebook

If you want the generated notebooks to work without an internet connection or with an unreliable connection (e.g. if you see Loading BokehJS ... but never BokehJS sucessfully loaded), then restart the Jupyter notebook server using:

BOKEH_RESOURCES=inline jupyter notebook --NotebookApp.iopub_data_rate_limit=100000000

See dashboard.ipynb in this directory for a Datashder dashboard for viewing data.