每日一练 | Data Scientist & Business Analyst 面试题 143

大数据应用 · 公众号 · 大数据 · 2017-07-28 09:15

正文

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 43

DS Interview Questions

Give some classification situations where you will use an SVM over a RandomForest Machine Learning algorithm and vice-versa.

BA Interview Questions

R language:

Write a for loop that prints the Displacement (‘disp’) of the ‘mtcars’ dataset.

a. This loop will only print observations of 160 or higher in ‘disp’.

b. This loop will stop as soon as an observation is smaller than 160 in ‘disp’.

欲知答案如何？请见下期分解！

Day 42 答案揭晓

DS Interview Questions

What is seasonality in time series modelling?

Seasonality in time series occurs when time series shows a repeated pattern over time. E.g., stationary sales decreases during holiday season, air conditioner sales increases during the summers etc. are few examples of seasonality in a time series.

Seasonality makes your time series non-stationary because average value of the variables at different time periods. Differentiating a time series is generally known as the best method of removing seasonality from a time series. Seasonal differencing can be defined as a numerical difference between a particular value and a value with a periodic lag.