Usage permissions, license and copyright

Permission to use, copy, modify, and distribute this software and its documentation under the terms of the GNU General Public License is hereby granted. No representations are made about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty. See the GNU General Public License for more details.

COMDAST has been developed for research purposes and is under active development. Authors are happy to share the code with anyone interested under the terms of the GNU General Public License without any gurantee or support.

We are happy to share our software. Here's how to download

  1. Check to see if you are running or install Mercurial revision control software (see notes below if you are unsure)
  2. Request a username and password to the software repo by emailing Jitendra Kumar from your institutional email and give the following items of information
    • Name
    • Title (staff, student, faculty, etc.)
    • Organization/university (including division/department)
    • If student please also give name and email of adviser/supervisor
  3. And finally clone a copy of COMDAST on your commputer with:
    hg clone
    and enter your username and password when prompted

  4. Update your copy of COMDAST with:
    hg pull -u

The source code can be also be browsed online at

More notes


In order to keep you advised of any software revisions COMDAST is released through a Mercurial based repository. If you use Linux and are unsure if you have Mercurial type "hg" from your terminal shell to check. If you do not have Mercurial it is easy to install on most Linux machines (Ubuntu, Debian: apt-get install mercurial | Fedora: yum install mercurial | OpenSUSE: zypper install mercurial | Gentoo: emerge mercurial).

Downscaling examples in our repo

The scripts we provide through our repo were used to do site (temporal) and regional (space & time) downscaling of CMIP5 model output ( We used CRU-NCEP as our training (target) data source. The site-level downscaling subdirectory contains scripts and example ASCII text data for downscaling. The regional-level subdirectory uses the original NetCDF data. If you are using different data formats (HDF, etc.) or different data sources you should probably write your own scripts for parsing the data and use the COMDAST "neural_networks", "normalize", and "" code for downscaling.

To inspect some example before-and-after data download and un-compress one of the following files: or examples.tar.gz (12 MB). Inside are 2 NetCDF files both representing 1 year of temperature data over Western North America. One file has the original 2°, monthly mean air temperature, and the other is the downscaled 0.5°, 6-hourly version.

Code development

COMDAST includes several algorithms, example data sets and plotting tools and scripts. An example downscaling routine is demonstrated with the execution of a shell script. The core of the COMDAST is written in C language using Message Pasing Interface (MPI) for distributed memory parallelism. All developmet and testing has been done on Linux based machines using open source tools and softwares. Subscribe to the COMDAST-dev mailing list for latest development updates, questions and help.