eBook - ePub
Data Science and Machine Learning Interview Questions Using R
Data Science and Machine Learning Interview Questions Using R
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eBook - ePub
Data Science and Machine Learning Interview Questions Using R
Data Science and Machine Learning Interview Questions Using R
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Table of contents
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About This Book
Get answers to frequently asked questions on Data Science and Machine Learning using R Key Features
- Understand the capabilities of the R programming language
- Most of the machine learning algorithms and their R implementation covered in depth
- Answers on conceptual data science concepts are also covered
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Description
This book prepares you for the Data Scientist and Machine Learning Engineer interview w.r.t. R programming language.
The book is divided into various parts, making it easy for you to remember and associate with the questions asked in an interview. It covers multiple possible transformations and data filtering techniques in depth. You will be able to create visualizations like graphs and charts using your data. You will also see some examples of how to build complex charts with this data. This book covers the frequently asked interview questions and shares insights on the kind of answers that will help you get this job.
By the end of this book, you will not only crack the interview but will also have a solid command of the concepts of Data Science as well as R programming. What will you learn
- Get answers to the basics, intermediate and advanced questions on R programming
- Understand the transformation and filtering capabilities of R
- Know how to perform visualization using R
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Who this book is for
This book is a must for anyone interested in Data Science and Machine Learning. Anyone who wants to clear the interview can use it as a last-minute revision guide. Table of Contents
1. Data Science basic questions and terms
2. R programming questions
3. GGPLOT Questions
4. Statistics with excel sheet About the Author
Vishwanathan Narayanan has 18 years of experience in the field of information technology and data analysis. He made many enterprise-level applications with stable output and scalability.Advanced level data analysis for complex problems using both R and Python has been the key area of work for many years. Extreme programmer on Java, Python, R, and many more technologies
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Yes, you can access Data Science and Machine Learning Interview Questions Using R by Vishwanathan Narayanan in PDF and/or ePUB format, as well as other popular books in Computer Science & Data Processing. We have over one million books available in our catalogue for you to explore.
Information
SECTION 1
Data Science Basic Questions and Terms
Learning objective
In this session, we will learn about data science terminologies and machine learning.
Key points
- Steps involved in data science
- Variables and types
- Machine learning and types
- Algorithms used in Machine learning
Let us begin!
- Explain the steps involved in data science? Ans. Following are the steps involved:1) Get Data from various Data sources available2) Generate research question from data3) Identify variables present in data. Also, identify important variables or variables to be analyzed as such4) Generate hypothesis5) Analyze data using graph data like a histogram for example6) Fit a model from analyzed data7) Accept or reject the hypothesis8) Research question answer foundFigure 1.1: Steps involved in data scienceExample of above steps:1) Get data related to temperature for India reference https://data.gov.in/catalog/annual-and-seasonal-maximum-temperature-india
A template of data set is as follows:
βYEARβ, βANNUALβ, βJAN-FEBβ, βMAR-MAYβ, βJUN-SEPβ, βOCT-DECβ
β1901β, β28.96β, β23.27β, β31.46β, β31.27β, β27.25β
β1902β, β29.22β, β25.75β, β31.76β, β31.09β, β26.49β
β1903β, β28.47β, β24.24β, β30.71β, β30.92β, β26.26β
β1904β, β28.49β, β23.62β, β30.95β, β30.67β, β26.40β
β1905β, β28.30β, β22.25β, β30.00β, β31.33β, β26.57β
β1906β, β28.73β, β23.03β, β31.11β, β30.86β, β27.29β
β1907β, β28.65β, β24.23β, β29.92β, β30.80β, β27.36β
β1908β, β28.83β, β24.42β, β31.43β, β30.72β, β26.64β
β1909β, β28.39β, β23.52β, β31.02β, β30.33β, β26.88β
β1910β, β28.53β, β24.20β, β31.14β, β30.48β, β26.20β
β1911β, β28.62β, β23.90β, β30.70β, β31.14β, β26.31β
β1912β, β28.95β, β24.88β, β31.10β, β31.15β, β26.57β
β1913β, β28.67β, β24.25β, β30.89β, β30.92β, β26.42β
β1914β, β28.66β, β24.59β, β30.73β, β30.84β, β26.40β
β1915β, β28.94β, β23.22β, β31.06β, β31.51β, β27.18β
β1916β, β28.82β, β24.57β, β31.88β, β30.52β, β26.32β
β1917β, β28.11β, β24.52β, β30.06β, β30.24β, β25.74β
β1918β, β28.66β, β23.57β, β30.68β, β31.11β, β26.77β
2) The research question is the annual temperature in India rising?3) Variable of interest from the above data set ANNUAL4) Hypothesis: Temperature is rising5) Analyze data from the above data set:Figure 1.2: Graph showing year vs. temperature6) Fit the model7) Hypothesis accepted or rejected - Define a variable? Ans. Anything which keeps on changing is called variable.
- Explain different types of variables? Ans. Variables are of the following type:
- Dependant/Outcome: A variable being affected for example annual temperature in the above example.
- Independent/Predictor: A variable affecting the outcome e.g. deforestation, pollution, and so on in the above example.
- Define Categorical measurement? Ans. Categorical measurement contains categories i.e. distinct entities. Example of categories of life on earth is plants, animals, and so on.
- Define Binary variables? Ans. Binary variables are those in which only two classes exist like live or dead male or female on or off.
- Define Nominal measurement? Ans. Nominal measurements are those of more than two classes. Such categories can be numbers too.
- Explain the Ordinal variable? Ans. These are nominal variables that have a logical order. Examples include team ranks in cricket or football, merit list of students appearing for grade students.
- Define Continuous variables? Ans. These are variables that can take can any value on the measurement scale example includes pitch of voice which can take any possible value within the range.
- Define Discrete variables? Ans. These are variables that can take fixed values in the range. Example number of customers in a bank.
- Is it possible to convert continuous values to discrete and vice versa? Ans. Yes based upon the motive of study it is possible to convert discrete values to continuous and vice versa. Example Level of water in the tank can take any value in the range and as such a continuous variable.But we can approximate the same to three different levels like empty, full, or half empty and this now becomes discrete.
- Explain the interval variables? Ans. These are variables that are grouped on the interval. E.g. is age can be divided into the range like 1-10, 10-20, 20-30, and so on and the person with a particular age would be placed in one of the above groups. When intervals are equal they represent the difference in the equal property being measured.
- Explain the ratio variables? Ans. This is a subtype of interval variables where the ratio of scales is used for measurement.E.g. Water representation in chemistry is H2O which represent two molecules of hydrogen and one molecule of oxygen. Thus the ratio of elements is 2: 1.
- Define Univariate and Bivariate variables? Ans. Following are the definitions:
- Univariate variable: When the variable under consideration is only one then it is called a univariate variable study.
- Bivariate variable: Involves the study of the relationship between two variables.
- Explain the measurement error? Ans. The discrepancy between the measured value and actual value in terms of number is called measurement error.E.g. While buying fruits from a vendor in kilograms, if we wanted 1 kilogram of fruits and the vendorβs weighing machine showed 1 kilogram when we brought the same. After checking the same in another machine if the measured value show 0.1 kilograms less than expected then this difference is what we call as measurement error.
- Define Validity? Ans. Validity implies whether an instrument measures what it is supposed to measure.
- Explain Reliability? Ans. Reliability implies whether the instrument gives consistent results across different conditions.E.g. if we test the same value twice on the same entity then the results from the instrument should remain the same if it has to be reliable. Such test is known as test-retest.
- Explain different ways to test hypotheses? Ans. There are two ways in which hypotheses can be tested1) Correlational research:
- This is also known as cross-sectional research
- This involves observing the natural pattern or occurrence to test
- Original occurrences are not manipulated
2) Experimental research:- We select the variabl...
Table of contents
- Cover Page
- Title Page
- Copyright Page
- Dedication
- About the Author
- Foreword
- About the Reviewer
- Acknowledgement
- Preface
- Errata
- Table of Contents
- 1. Data Science Basic Questions and Terms
- 2. Programming Questions
- 3. GGPLOT Questions
- 4. Statistics with Excel Sheet