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Retrieving data for demos and use of the PMP
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Sample model and observational data are provided via a `jupyter notebook demo <https://github.com/PCMDI/pcmdi_metrics/blob/master/doc/jupyter/Demo/Demo_0_download_data.ipynb>`_.  This is the first of multiple PMP demos. It enables a user to download all sample data before running the other demos that provide interactive examples of the different summary statistics provided by the PMP.  More info is available for `preparing to run these notebooks <https://github.com/PCMDI/pcmdi_metrics/blob/master/doc/jupyter/Demo/README.md>`_.  

For users that are unfamiliar with Jupyter notebooks or just want to download the sample data without interactively running the demo, you can download the data by launching python from a PMP environment created from conda.  You can then enter the following form the python command prompt :: 

    import requests
    r = requests.get("https://pcmdiweb.llnl.gov/pss/pmpdata/cmec_tutorial_files.txt")
    with open("data_files.txt","wb") as f:
       f.write(r.content)

A location where you want to store the demo data locally can be set: ::

    demo_data_directory = 'MyDemoPath' 


After you have set the location for the demo_output you can download it by entering the following: ::

    import cdat_info
    cdat_info.download_sample_data_files("data_files.txt", demo_data_directory)

The PMP demo data is used for multiple demos. It is ~300MB. The best way to run these demos is via Jupyter notebooks.  Running this initial demo for downloading sample data also on-the-fly creates demo parameter files with the user selection of the demo_data_directory.