Reference

[1]https://www.tensorflow.org/versions/r0.9/get_started/os_setup.html#virtualenv-installation

[2]https://www.tensorflow.org/versions/r0.9/get_started/os_setup.html#optional-install-cuda-gpus-on-linux

[3]https://www.tensorflow.org/versions/r0.9/get_started/basic_usage.html#basic-usage