more references

hw6/README.md

@@ -6,3 +6,38 @@ This is ML2017 Spring hw6 competition. You need to implement matrix factorizatio
 <https://inclass.kaggle.com/c/ml2017-hw6> 
 
 
+## Reference
+<https://github.com/bradleypallen/keras-movielens-cf> 
+
+<https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.apply.html> 
+<https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.to_csv.html> 
+<http:https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.html> 
+
+<http:https://scikit-learn.org/stable/modules/generated/sklearn.manifold.TSNE.html> 
+<https://docs.scipy.org/doc/numpy/reference/generated/numpy.random.rand.html> 
+
+### Keras Function API
+<https://keras.io/getting-started/functional-api-guide/> 
+
+#### keras.layers.merge
+<https://stackoverflow.com/questions/43196636/how-to-concatenate-two-layers-in-keras> 
+<https://github.com/fchollet/keras/issues/3921> 
+
+
+#### \*args v.s. \*\*kwargs
+<https://stackoverflow.com/questions/3394835/args-and-kwargs> 
+
+
+#### Matplotlib
+<https://liam0205.me/2014/09/11/matplotlib-tutorial-zh-cn/> 
+<https://indico.io/blog/visualizing-with-t-sne/> 
+<https://matplotlib.org/devdocs/api/_as_gen/matplotlib.pyplot.gca.html> 
+<http:https://www.cnblogs.com/frandy/archive/2012/09/27/python_pyplot_subplot.html> 
+<https://stackoverflow.com/questions/4700614/how-to-put-the-legend-out-of-the-plot> 
+<https://stackoverflow.com/questions/17682216/scatter-plot-and-color-mapping-in-python> 
+<https://stackoverflow.com/questions/17411940/matplotlib-scatter-plot-legend> 
+<https://matplotlib.org/api/pyplot_api.html> 
+<https://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.legend> 
+<https://stackoverflow.com/questions/14720331/how-to-generate-random-colors-in-matplotlib> 
+<https://stackoverflow.com/questions/8931268/using-colormaps-to-set-color-of-line-in-matplotlib> 
+<https://stackoverflow.com/questions/18619880/matplotlib-adjust-figure-margin>