From 123ae36c635dbb50c359e282428dcc07327d3802 Mon Sep 17 00:00:00 2001
From: Duy-Nguyen Ta <thduynguyen@gmail.com>
Date: Sat, 25 Mar 2017 23:38:49 -0400
Subject: [PATCH] put back requirements.txt, now with backports.

---
 cython/README.md        | 10 ++++------
 cython/requirements.txt |  3 +++
 2 files changed, 7 insertions(+), 6 deletions(-)
 create mode 100644 cython/requirements.txt

diff --git a/cython/README.md b/cython/README.md
index efa3646ec..544154f58 100644
--- a/cython/README.md
+++ b/cython/README.md
@@ -2,17 +2,15 @@ This is the Cython/Python wrapper around the GTSAM C++ library.
 
 INSTALL
 =======
-- This wrapper needs Cython(>=0.25), numpy and eigency, which can be installed
+- This wrapper needs Cython(>=0.25.2), backports_abc>=0.5, numpy, which can be installed
 as follows:
 
 ```bash
- cd <gtsam_folder>/cython
- pip install numpy>=1.11.1
- pip install Cython>=0.25.1
- pip install eigency
+ pip install -r <gtsam_folder>/cython/requirements.txt
 ```
 
-Note: If your eigency fails to install via pip, try to install it from source as below:
+- It also needs Eigency, a package that interfaces between C++'s Eigen and Python's numpy.
+You can try to install via pip: "pip install eigency". If that fails, install it from source as follows:
 
 ```bash
 git clone https://github.com/wouterboomsma/eigency.git
diff --git a/cython/requirements.txt b/cython/requirements.txt
new file mode 100644
index 000000000..3fdf1a7b8
--- /dev/null
+++ b/cython/requirements.txt
@@ -0,0 +1,3 @@
+Cython>=-0.25.2
+backports_abc>=0.5
+numpy>=1.12.0