每日一练 | Data Scientist & Business Analyst 面试题 128
从6月15日起，数据应用学院将与你一起温习数据科学（DS）和商业分析（BA）领域常见的面试问题。希望积极寻求相关领域工作的你每天关注我们的问题并且与我们一起思考，我们将会在第二天给出答案。
Day 28
DS Interview Questions
What is the difference between stochastic gradient descent (SGD) and gradient descent (GD)?
BA Interview Questions
What is the difference between library( ) and require( ) functions in R language?
欲知答案如何？请见下期分解！
Day 27 答案揭晓
DS Interview Questions
While working on a data set, how do you select important variables?
Explain your methods.
Remove the correlated variables prior to selecting important variables
Use linear regression and select variables based on p values
Use Forward Selection, Backward Selection, Stepwise Selection
Use Random Forest, Xgboost and plot variable importance chart
Measure information gain for the available set of features and select top n features accordingly.
BA Interview Questions
What is the value of f (2) for the following R code?
The answer to the above code snippet is 35. The value of “a” passed to the function is 2 and the value for “b” defined in the function f (a) is 3. So the output would be 3^3 + g (2). The function g is defined in the global environment and it takes the value of b as 4(due to lexical scoping in R) not 3 returning a value 2*4= 8 to the function f. The result will be 3^3+8= 35.
长期招募
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深度讨论数据应用
调研行业发展
要求：
对数据应用极为感兴趣
具备数据分析基础
具有一定BUSINESS INSIGHT
写作能力强
感兴趣的同学发送简历及writing sample到hr@dataapplab.com，邮件标题“申请翻译/Technical Writer”。
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