# Contributing Changes¶

The best way to contribute to the reflectometry package is to work from a copy of the source tree in the revision control system.

The refl1d project is hosted on github at:

https://github.com/reflectometry/refl1d

You will need the git source control software for your computer. This can be downloaded from the git page, or you can use an integrated development environment (IDE) such as Eclipse and PyCharm, which may have git built in.

## Simple patches¶

If you want to make one or two tiny changes, it is easiest to clone the project, make the changes, document and test, then send a patch.

Clone the project as follows:

git clone https://github.com/reflectometry/refl1d.git


You will need bumps and periodictable to run. If you are fixing bugs in the scattering length density calculator or the fitting engine, you will want to clone the repositories as sister directories to the refl1d source tree:

git clone https://github.com/bumps/bumps.git
git clone https://github.com/pkienzle/periodictable.git


If you are only working with the refl1d modeling code, then you can install bumps and periodictable using pip:

pip install periodictable bumps


To run the package from the source tree use the following:

cd refl1d
python run.py


This will first build the package into the build directory then run it. Any changes you make in the source directory will automatically be used in the new version.

As you make changes to the package, you can see what you have done using git:

git status
git diff


Please update the documentation and add tests for your changes. We use doctests on all of our examples that we know our documentation is correct. More thorough tests are found in test directory. With the nosetest package, you can run the tests using:

python tests.py


Nose is available on linux form apt-get

When all the tests run, create a patch and send it to paul.kienzle@nist.gov:

git diff > patch


## Larger changes¶

For a larger set of changes, you should fork refl1d on github, and issue pull requests for each part.

Once you have create the fork, the clone line is slightly different:

git clone https://github.com/YourGithubAccount/refl1d


After you have tested your changes, you will need to push them to your github fork:

git log
git commit -a -m "short sentence describing what the change is for"
git push


Good commit messages are a bit of an art. Ideally you should be able to read through the commit messages and create a “what’s new” summary without looking at the actual code.

Make sure your fork is up to date before issuing a pull request. You can track updates to the original refl1d package using:

git remote add refl1d https://github.com/reflectometry/refl1d
git fetch refl1d
git merge refl1d/master
git push


When making changes, you need to take care that they work on different versions of python. In particular, RHEL6, Centos6.5, Rocks and ScientificLinux all run python 2.6, most linux/windows/mac users run python 2.7, but some of the more bleeding edge distributions run 3.3/3.4. The anaconda distribution makes it convenient to maintain multiple independent environments Even better is to test against all python versions 2.6, 2.7, 3.3, 3.4:

pythonX.Y tests.py
pythonX.Y run.py


When all the tests run, issue a pull request from your github account.

### Building Documentation¶

Building the package documentation requires a working Sphinx installation, and latex to build the pdf. As of this writing we are using sphinx 1.2.

The command line to build the docs is as follows:

(cd doc && make clean html pdf)


You can see the result by pointing your browser to:

doc/_build/html/index.html
doc/_build/latex/Refl1d.pdf


Note that this only works with a unix-like environment for now since we are using make. On windows, you can run sphinx directly from python:

cd doc
python -m sphinx.__init__ -b html -d _build/doctrees . _build/html


ReStructured text format does not have a nice syntax for superscripts and subscripts. Units such as g·cm-3 are entered using macros such as |g/cm^3| to hide the details. The complete list of macros is available in

doc/sphinx/rst_prolog

In addition to macros for units, we also define cdot, angstrom and degrees unicode characters here. The corresponding latex symbols are defined in doc/sphinx/conf.py.

There is a bug in older sphinx versions (e.g., 1.0.7) in which latex tables cannot be created. You can fix this by changing:

self.body.append(self.table.colspec)


to:

self.body.append(self.table.colspec.lower())


in site-packages/sphinx/writers/latex.py.

### Windows Installer¶

To build a windows standalone executable with py2exe you may first need to create an empty file named Lib\numpy\distutils\tests\__init__.py in your python directory (usually C:\Python2.7. Without this file, py2exe raises an error when it is searching for the parts of the numpy package. This may be fixed on recent versions of numpy. Next, update the __version__ tag in refl1d/__init__.py to mark it as your own.

Now you can build the standalone executable using:

python setup_py2exe


This creates a dist subdirectory in the source tree containing everything needed to run the application including python and all required packages.

• Visual C++ 2008 Redistributable Package (x86) 11/29/2007
• Inno Setup 5.3.10 QuickStart Pack

The C++ redistributable package is needed for programs compiled with the Microsoft Visual C++ compiler, including the standard build of the Python interpreter for Windows. It is available as vcredist_x86.exe from the Microsoft Download Center. Be careful to select the version that corresponds to the one used to build the Python interpreter — different versions can have the same name. For the Python 2.6 standard build, the file is 1.7 Mb and is dated 11/29/2007. We have a copy (vcredist_x86.exe) on our website for your convenience. Save it to the C:\Python26 directory so the installer script can find it.

Inno Setup creates the installer executable. When installing Inno Setup, be sure to choose the ‘Install Inno Setup Preprocessor’ option.

With all the pieces in place, you can run through all steps of the build and install by changing to the top level python directory and typing:

python master_builder.py


This creates the redistributable installer refl1d-<version>-win32.exe for Windows one level up in the directory tree. In addition, source archives in zip and tar.gz format are produced as well as text files listing the contents of the installer and the archives.

### OS/X Installer¶

To build a Mac OS/X standalone executable you will need the py2app package. This should already be available in your mac python environment.

Build the executable using:

python setup_py2app


This creates a .dmg file in the dist directory with the Refl1D app inside.