How to configure singa-ps?
1. make mxnet into "mxnet/lib/libmxnet.so"
2. copy "mxnet/lib/libmxnet.so" into "mxnet/python/mxnet"
1. copy the folder "mxnet/python/mxnet" into the working directory.
2. copy "singa_kvstore.py" and "SingaOpt.py" into the working directory.

How to use singa-ps?  
1. import singa_kvstore;

2. create kvstore for ps;
   For example:
   #------------------------start example------------------------------------------------------------------
   kv_type = 'dist_sync' # set synchronization mode, e.g., 'dist_async','dist_sync'
   kv = singa_kvstore.create_kvstore(kv_type,
                                     'SingaSGD', # set other options, like 'sgd','adam', can use mxnet optimizer
                                     lr=0.005, 
                                     momentum=0.9, 
                                     weight_decay=1e-5)
   #------------------------end example--------------------------------------------------------------------

3. use kvstore to update parameters after the loss is computed;
   For example:
   #------------------------start example------------------------------------------------------------------
   singa_kvstore.backward_and_update(kv,loss)
   #------------------------end example--------------------------------------------------------------------

(mnist_cnn.py is a detailed example)