Installing Halide
================================================================

For now, we recommend building Halide from source for the full functionality.
Clone the repository to your local directory first:

.. code-block:: bash

	git clone https://github.com/halide/Halide


Then follow the `building instructions
<https://github.com/halide/Halide#building-halide>`_ from the official readme.

This tutorial also uses the Python bindings. To build the Python bindings,
first build main Halide code. Then go to the ``python_bindings`` directory, and
install the following requirements:

.. code-block:: bash

	$ pip install numpy scipy pillow imageio pybind11

Next run

.. code-block:: bash

	$ make

After building the Python bindings, we need to point Python to it so that we
can ``import halide``. Add ``/path/to/halide/python_bindings/bin`` to your
``PYTHONPATH`` environment variable (e.g. ``export
PYTHONPATH=/path/to/halide/python_bindings/bin:$PYTHONPATH``).

There is one more step. You need to install the autoscheduler. There are
several autoschedulers in Halide but we will use the ``gradient_autoscheduler``
as it is currently the only autoscheduler that supports GPU scheduling. From the
root directory of Halide:

.. code-block:: bash

	$ cd apps/gradient_autoscheduler
	$ make

And again add ``/path/to/halide/apps/gradient_autoscheduler/bin`` to
``PYTHONPATH``.

After this, go to the Python console and try

.. code-block:: py

	import halide
	import libgradient_autoscheduler

If the imports are successful, you are ready!