深度学习框架keras:如何设置后端Tensorflow/theano

修改keras配置文件，可以更改keras后端依赖的框架：

sudo gedit ~/.keras/keras.json

{"epsilon": 1e-07, "floatx": "float32", "image_data_format":"channels_last" ,"backend": "tensorflow","image_dim_ordering":"th"
}

把tensorflow改为theano，
同时把channels_last改为channels_first,
即可切换后端框架，如下：

{"image_data_format": "channels_first","epsilon": 1e-07,"backend": "theano","floatx": "float32""image_dim_ordering":"th"
}