I have read and followed this answer to install scipy/numpy/theano. However, it still failed on the same error of missing Fortran compiler after brew install gcc. While Home
The following worked for me:
sudo apt-get install gfortran
on my system:
Ubuntu 15.10 (Linux 4.2.0-19-generic #23-Ubuntu x86_64 x86_64 x86_64 GNU/Linux)