DOC: update DataLad access instructions #1

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loj merged 1 commit from README into master 2021-04-28 08:24:35 +00:00

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README
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@ -28,60 +28,74 @@ For more information about the project visit: http://studyforrest.org
How to obtain the data files How to obtain the data files
---------------------------- ----------------------------
This repository contains metadata and information on the identity of all This repository is a `DataLad <https://www.datalad.org/>`__ dataset. It provides
included files. However, the actual content of the (sometime large) data fine-grained data access down to the level of individual files, and allows for
files is stored elsewhere. tracking future updates. In order to use this repository for data retrieval,
`DataLad <https://www.datalad.org>`_ is required.
It is a free and open source command line tool, available for all
major operating systems, and builds up on Git and `git-annex
<https://git-annex.branchable.com>`__ to allow sharing, synchronizing, and
version controlling collections of large files. You can find information on
how to install DataLad at `handbook.datalad.org/en/latest/intro/installation.html
<http://handbook.datalad.org/en/latest/intro/installation.html>`_.
Using DataLad (http://datalad.org) Get the dataset
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^^^^^^^^^^^^^^^
Install this dataset: A DataLad dataset can be ``cloned`` by running::
datalad install URL datalad clone <url>
Obtain any files (example all files, but individual files can be requested) Once a dataset is cloned, it is a light-weight directory on your local machine.
At this point, it contains only small metadata and information on the
identity of the files in the dataset, but not actual *content* of the
(sometimes large) data files.
datalad get . Retrieve dataset content
^^^^^^^^^^^^^^^^^^^^^^^^
Obtain dataset updated After cloning a dataset, you can retrieve file contents by running::
datalad update --merge datalad get <path/to/directory/or/file>
This command will trigger a download of the files, directories, or
subdatasets you have specified.
Using git/git-annex DataLad datasets can contain other datasets, so called *subdatasets*. If you
~~~~~~~~~~~~~~~~~~~ clone the top-level dataset, subdatasets do not yet contain metadata and
information on the identity of files, but appear to be empty directories. In
order to retrieve file availability metadata in subdatasets, run::
To obtain any dataset component, git-annex_ is required in addition to Git_. datalad get -n <path/to/subdataset>
1. Clone this repository to the desired location. Afterwards, you can browse the retrieved metadata to find out about
2. Enter the directory with the local clone and run:: subdataset contents, and retrieve individual files with ``datalad get``. If you
use ``datalad get <path/to/subdataset>``, all contents of the subdataset will
be downloaded at once.
git annex init Stay up-to-date
^^^^^^^^^^^^^^^
Older versions of git-annex may require you to run the following DataLad datasets can be updated. The command ``datalad update`` will *fetch*
command immediately afterwards:: updates and store them on a different branch (by default
``remotes/origin/master``). Running::
git annex enableremote mddatasrc datalad update --merge
Now any desired dataset component can be obtained by using the ``git annex get`` will *pull* available updates and integrate them in one go.
command. To obtain the entire dataset content run::
git annex get . Find out what has been done
^^^^^^^^^^^^^^^^^^^^^^^^^^^
Keep data up-to-date DataLad datasets contain their history in the ``git log``.
-------------------- By running ``git log`` (or a tool that displays Git history) in the dataset or on
specific files, you can find out what has been done to the dataset or to individual files
by whom, and when.
If updates to this dataset are made in the future, update any local clone by More information
running:: ^^^^^^^^^^^^^^^^
git pull More information on DataLad and how to use it can be found in the DataLad Handbook at
`handbook.datalad.org <http://handbook.datalad.org/en/latest/index.html>`_. The
followed by:: chapter "DataLad datasets" can help you to familiarize yourself with the
concept of a dataset.
git annex get .
to fetch all new files.
.. _Git: http://www.git-scm.com
.. _git-annex: http://git-annex.branchable.com/