Guangning Yu guangningyu

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Data Scientist, Full Stack Developer

guangningyu / common_js_operations

Last active November 12, 2018 03:56

	// Filter object array based on attributes
	var foo = [{'a':1, 'b':2}, {'a':2}, {'a':1}]
	foo.find(o => o.a === 1) // return { a: 1, b: 2 }

guangningyu / test_python_static_variable.py

Created October 12, 2018 03:00

test Python static variable

	class Person(object):
	number = 0 # <= define a static variable

	def __init__(self, name):
	self.name = name

	def say_hello(self):
	print("Hello, I'm {name}!".format(name = self.name))

	def say_number(self):

guangningyu / apply_yaml_filters_to_pyspark_dataframe.py

Last active October 9, 2018 10:42

Apply filters defined in yaml file to PySpark dataframe

	#!/usr/bin/env python

	import yaml
	from pyspark import SparkContext
	from pyspark.sql import SQLContext

	sc = SparkContext()
	sqlContext = SQLContext(sc)

	# create dataframe

guangningyu / try_bcrypt.js

Last active June 28, 2018 07:17

https://www.npmjs.com/package/bcrypt

	var bcrypt = require('bcrypt');
	const saltRounds = 10;
	const myPlaintextPassword = 's0/\/\P4$$w0rD';
	const someOtherPlaintextPassword = 'not_bacon';

	// Hash a password

	bcrypt.genSalt(saltRounds, function(err, salt) {
	bcrypt.hash(myPlaintextPassword, salt, function(err, hash) {
	console.log('> hash a password (generate a salt and hash on separate function calls)');

guangningyu / redux_demo.html

Last active December 28, 2017 14:22

Handmade Redux Demo

	<!DOCTYPE html>
	<html>
	<head>
	<title>Handmade Redux Demo</title>
	</head>
	<body>
	<div>
	Counter:
	<span id="counter"></span>
	</div>

guangningyu / mkdir4sbt.sh

Created November 9, 2017 22:22

	#!/bin/bash

	mkdir -p src/{main,test}/{java,resources,scala}
	mkdir lib project target

	# create an initial build.sbt file
	echo 'name := "MyProject"
	version := "1.0"
	scalaVersion := "2.10.0"' > build.sbt

guangningyu / understand_implicit.scala

Last active November 9, 2017 04:27

	object HelloWorld {
	case class Text(content: String)
	case class Prefix(text: String)

	// step 2: capture the String conversion in implicit function;
	// then find an implicit parameter and end up with finding "prefixLOL"
	implicit def String2Text(content: String)(implicit prefix: Prefix) = {
	// step 3: return instance of Text
	Text(prefix.text + " " + content)
	}

guangningyu / singular_value_decomposition.py

Created August 8, 2017 15:06

Reference: [Singular Value Decomposition Part 2: Theorem, Proof, Algorithm](https://jeremykun.com/2016/05/16/singular-value-decomposition-part-2-theorem-proof-algorithm/)

	#!/usr/bin/env python
	# -- coding: utf-8 --

	'''
	Calculate the singular value decomposition using the power method.
	'''

	import numpy as np
	from numpy.linalg import norm
	from random import normalvariate

guangningyu / neural_network.py

Created July 25, 2017 17:00

An implementation of Neural Network. Reference: [Implementing a Neural Network from Scratch in Python – An Introduction](http://www.wildml.com/2015/09/implementing-a-neural-network-from-scratch/)

	#!/usr/bin/env python

	import numpy as np
	import sklearn.datasets
	import matplotlib.pyplot as plt


	def load_data(n_samples=100, noise=None):
	np.random.seed(0)
	return sklearn.datasets.make_moons(n_samples=n_samples, noise=noise)

guangningyu / keras-regression.py

Created July 19, 2017 04:14

Reference: [Regression Tutorial with the Keras Deep Learning Library in Python](http://machinelearningmastery.com/regression-tutorial-keras-deep-learning-library-python/)

	#!/usr/bin/env python

	import urllib2
	import numpy as np
	from keras.models import Sequential
	from keras.layers import Dense
	from keras.wrappers.scikit_learn import KerasRegressor
	from sklearn.model_selection import cross_val_score
	from sklearn.model_selection import KFold
	from sklearn.preprocessing import StandardScaler