DEV Community: VICTOR OMONDI

Basic Introduction To R

VICTOR OMONDI — Wed, 06 May 2020 17:01:13 +0000

In this article we will cover the intro basics to R Programming Language. This article is meant for people willing to start programming in R, beginners in R who are willing to expand their already gained knowledge in R, or people willing to start their Data Science journey using R programming language. If you are familiar with other programming languages, getting to understand R programming language will be as easy as drinking water.

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What is R?

Well! It is a programming language, often used in statistics and data science, but let's get a clear definition from Wikipedia

R is a programming language for statistical computing and data visualization. It has been adopted in the fields of data mining, bioinformatics, and data analysis.

View on Wikipedia>

According to Wikipedia: R is a programming language and free software environment for statistical computing and graphics supported by the R Foundation for Statistical Computing. The R language is widely used among statisticians and data miners for developing statistical software and data analysis.

R language provides a wide variety of statistical (linear and nonlinear modelling, classical statistical tests, time-series analysis, classification, clustering, …) and graphical techniques, and is highly extensible. READ MORE>>

How to Install and Getting Started With R

Since this article focuses on the basics of R programming language, for instruction on how to install R and R studio please Check this Edx Article

Once you have R and Rstudio installed, let's proceed to the business of the Day.

What is R
How to Install and Getting Started With R
Intro To R Basics
- Comments
- R Arithmetic Operators
- Basic Data Types in R
More Resources

Intro To R Basics

Hello, World!

It's now like a rule that the first code you write when beginning to learn a programming language is a code that will display Hello, World! on the screen.

In order to display on the screen, R provides the print() function.

print prints its argument and returns it invisibly

In order to print Hello, World! in R, you need to pass the string "Hello, World!" in the print() function. the strings can be in double quotes "" or single quotes ''.

print("Hello, World!")

the output will be as follows:

[1] "Hello, World!"

Creating and Naming Variables

Variables helps your program claim a piece of memory when it's running. In R, variables allow you to store a value or an object. In simple terms, a variable is a named storage space. The variables created can later on be used in your program to perform various operations.
In R, <-, = or -> are used as the Assignment Operator to assign values to a variable name. Before creating variables, you must adhere to the rules of creating a Variable in R.

Rules for Naming Variables in R

Variable names MUST start with a letter, it can contain a letter, number, underscore (_) and period (.).

unlike other languages, Underscore(_) at the beginning of the variable name are NOT allowed in R
Keywords CANNOT be used to name variables
Special Character like #, or & and whitespace eg tab or space CANNOT be used in variable names
Variable names are Case Sensitive, therefore, my_name is different from my_Name.

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Below are examples of correct variable names and assignment in R

age <- 17
age

[1] 17

name.first = "Victor"
name.first

[1] "Victor"

17347.3847 -> weight_kgs
weight_kgs

[1] 17347.38

R Arithmetic Operators

An operator is a symbol that tells the compiler to perform specific mathematical or logical manipulations. R Arithmetic Operators are symbols that tells the compiler which mathematical operation to perform. R language supports the following arithmetic operators:

Arithmetic Operator	Function	Description	Example	Output
`+`	Addition	adds a number to another number	`3+2`	`[1] 5`
`-`	Subtraction	subtracts a number from another number	`3 - 2`	`[1] 1`
`*`	Multiplication	multiplies number with another number	`3 * 2`	`[1] 6`
`/`	Division	splits a number into equal parts	`3/2`	`[1] 1.5`
`^`	Exponentiation	raising a number to the power of another number	`3 ** 2`	`[1] 9`
`%%`	Modulo	The modulo returns the remainder of the division of the number to the left by the number on its right	`3 %% 2`	`[1] 1`

Let us use R arithmetic operators to calculate my age. We will use the already gained knowledge of variables and arithmetic operations we've discussed above.

year_of_birth = 2001
current_year = 2020
age = current_year - year_of_birt
age

[1] 19

As you can see age is a variable that stores the computations done when subtracting year_of_birth from current_year.

Comments

R makes use of the # sign to add comments. Comments are added to a source code so that you and others can understand what the R code is about. Comments are not run as R code, so they will not influence your programs computation computations.

# My year of Birth
year_of_birth = 2001

# The Current Year
current_year = 2020

# Calculating my age by subtracting year_of_birth from the current_year
age = current_year - year_of_birth
age

[1] 19

Basic Data Types in R

There are numerous data types in R programming language, we will cover the 4 basic types, that is, numerics, integers, logical and characters

Data type is the classification/categorization of data item. Everything in python is an object therefore, data types are classes and variables are the instance (object) of the data type.
Use class(variable_name) in order to understand to which data type a variable belongs.

To get you started with R Basic Data types, note the following:

Decimal values are called numerics

Natural Numbers are called Integers, Integers are also numerics

Boolean values, eg( FALSE or TRUE) are called logical. R is case sensitive, logicals must be in UPPERCASE

String values/text values are called characters

In the following code, we will create variables then use class() to check to which data type they belong.

my_age = 14
class(my_age)

my_weight = 90.6
class(my_weight)

my_name = "Victor" #Note how the quotation marks on the right indicate that "Victor" is a character
class(my_name)

is_teenager = TRUE
class(is_teanager)

[1] "numeric"
[1] "numeric"
[1] "character"
[1] "logical"

More Resources

R Introduction | R Tutorial: link
Introduction to R Online Course | DataCamp: link
Google

Programs

And that marks the end of this article, keep an eye for more R articles as I cover more of R programming language to get you started in Data Science with R. Have any question? Ask Me on Twitter:

https://twitter.com/VictorOmondi1997

Project Management, what is it?

VICTOR OMONDI — Sun, 16 Feb 2020 12:42:49 +0000

I was super exited this semester as Project Management was one of the units I was to undertake. I am currently a Third Year Student at Multimedia University Of Kenya. This article outlines the clear understanding of what a project is, what a project entails and what project management is.

What is A Project?

A project is a temporary undertaking that produces unique deliverables (product, services, etc.) using scarce resources.

A project is done in progression and has an owner (stakeholder).

Key Terms to note.

Temporary - has a start and an end. A project should have a start and an end. The team should decide the milestone the project should undertake.
Unique - something new or novel to the owner. A project should be something new that hasn't been created before by the owner.
Resources - require resources from different areas but there is the primary owner and/or sponsor. A project should utilize other resources or tools during creation of the product
Progression - a project is done in steps. Break down or decompose the project into small independent and manageable tasks. The tasks will be performed from start to the end.
Uncertainty - a project is done with a certain level of uncertainty.
Management - running something to be effective. Management has 3 parts:
- Planning
- Controlling
- Scheduling

1. Planning

Planning has 4 main things to be done

Break down or decompose the project into small independent and manageable tasks. Work Break Down structure can be used, it helps in breaking down the project.

Independent - Can be done on its own.

Determine the order or sequence in which the tasks will be performed from start to end.
Estimate the resources (time, cost, materials, machines, personnel, etc) required to complete each task.
- Use analogies method of estimation.
- Use past data to try and find what other people did
Masterpiece plan of how the project will look like from start to the end.

use network diagram. it is used to determine what to be done at what time.

2. Scheduling

Using the network diagram produce a master timetable of when each of the tasks will be done and by who.

use a Gantt chart.

3. Controlling.

Keep monitoring and evaluating the progress of the project by using the progress of the project by using the Gantt Chart developed above and having set milestones.

Project Management

Project management is a framework of tools, skills, knowledge, etc. applied to a project so as to achieve its objectives (success)

Agora Student Ambassador Program

VICTOR OMONDI — Tue, 04 Feb 2020 18:26:00 +0000

Agora Student Ambassador Program

The Agora Student Ambassador Program aims to identify energetic, passionate, brilliant, like-minded college students across the globe who are chosen to train on Agora Real-Time Communication for AI/ML, Web/App and IoT applications.

These Agora Student Ambassadors (ASA) are growing campus representatives and leaders, who are enthusiastic to learn innovative approaches to real-time communication, artificial intelligence, and voice/video technologies. By sharing their training with fellow colleagues, ASAs then act as the primary channel between campus students and Agora team.

Program Benefits for SA

◆ Formal Association with Agora via exclusive Agora gear and Ambassador Title.
◆ Opportunity to connect with Agora engineers and learn via web connect sessions and office hours.
◆ Partial travel support, speakership opportunities, and opportunities to train others.
◆ Sponsored funds/swag to assist in hosting sessions, training others, and speaking on and off-campus to promote your work.
◆ Contribute to shaping our product roadmap in the alpha stages of our new products.
◆ Exclusive access to the Agora beta programs.
◆ Annual Summit for all active ASA.
◆ Opportunity to work/intern at Agora and its partners.
◆ Linkedin Recommendations on successful active tenure.

And many more surprises!

Head on to below link to learn more and apply.

https://bit.ly/agorastudentambassador

Top YouTube Channels to Learn AI/ML/RL/DS

VICTOR OMONDI — Sun, 02 Feb 2020 13:16:33 +0000

So some really important Youtube Channels in the field of Artificial Intelligence (AI)/ Machine Learning (ML)/ Reinforcement Learning (RL)/
Data Science (DS) are:-

Sentdex https://www.youtube.com/user/sentdex
deeplizard https://www.youtube.com/channel/UC4UJ26WkceqONNF5S26OiVw
3Blue1Brown https://www.youtube.com/channel/UCYO_jab_esuFRV4b17AJtAw
Tech With Tim https://www.youtube.com/channel/UC4JX40jDee_tINbkjycV4Sg
Corey Schafer https://www.youtube.com/user/schafer5
Data School https://www.youtube.com/user/dataschool
Two Minute Papers https://www.youtube.com/user/keeroyz
Welch Labs https://www.youtube.com/user/Taylorns34
Luis Serrano https://www.youtube.com/channel/UCgBncpylJ1kiVaPyP-PZauQ
Simplilearn https://www.youtube.com/user/Simplilearn
Great Learning https://www.youtube.com/user/beaconelearning
DeepLearning.TV https://www.youtube.com/channel/UC9OeZkIwhzfv-_Cb7fCikLQ
TensorFlow https://www.youtube.com/channel/UC0rqucBdTuFTjJiefW5t-IQ
Deeplearning.ai https://www.youtube.com/channel/UCcIXc5mJsHVYTZR1maL5l9w
Code Bullet https://www.youtube.com/channel/UC0e3QhIYukixgh5VVpKHH9Q
edureka! https://www.youtube.com/user/edurekaIN
Lex Fridman https://www.youtube.com/channel/UCSHZKyawb77ixDdsGog4iWA
The Artificial Intelligence Channe https://www.youtube.com/user/Maaaarth
freeCodeCamp.org https://www.youtube.com/channel/UC8butISFwT-Wl7EV0hUK0BQ
CloudxLab https://www.youtube.com/channel/UC8mJ6DL1Q32UWyJUceoO8Jw
Alexander Amini https://www.youtube.com/user/Zan560
Jeff Heaton https://www.youtube.com/user/HeatonResearch

IF YOU KNOW SOME OTHER YOUTUBE CHANNEL THEN FEEL FREE TO ADD IN THE COMMENTS

Artificial Intelligence VS Data Science VS Machine Learning

VICTOR OMONDI — Thu, 23 Jan 2020 09:31:15 +0000

Artificial Intelligence

Artificial intelligence is a very wide term with applications ranging from robotics to text analysis.

Machine Learning

Machine learning is a subset of AI that focuses on a narrow range of activities.

Data Science

Data science isn’t exactly a subset of machine learning but it uses ML to analyze data and make predictions about the future. It combines machine learning with other disciplines like big data analytics and cloud computing. Data science is a practical application of machine learning with a complete focus on solving real-world problems."

Static methods in Python vs Javascript

VICTOR OMONDI — Thu, 23 Jan 2020 09:27:26 +0000

Python

class User():
    def __init__(self, username):
        self.username = username

    @staticmethod
    def what_am_i():
        return 'I can be called by User class and also by any User instance'

User.what_am_i()

Javascript

class User {
    constructor(username) {
        this.username = username;
    }

    static whatAmI() {
        return 'I can be called only by User class'
    }
}

User.whatAmI();

Thing to note

In python if we declare a static method it can be called by both the class and by any of the instances (objects) created from the class ✔️✔️✔️

Whereas in Javascript though, if we declare any static methods, it can only be accessed by calling it from the class and not by its instances 📣✔️✔️✔️

Javascript: Printing Object in Console

VICTOR OMONDI — Sat, 11 Jan 2020 21:30:19 +0000

If you're trying to print object in console and you're getting [object Object], then most probably you're trying to print the object as a string value. Add comma(,), and not plus operator(+)

Ex:

console.log('The value of object is: ' + obj)

❌❌

console.log('The value of object is: ' , obj)

✔️✔️

Javascript Devtool Tip: Print An Array in Console

VICTOR OMONDI — Sat, 11 Jan 2020 21:26:23 +0000

Trying to print an array in console?

Once Try using console.table() instead of console.log()

API Design Tip

VICTOR OMONDI — Sat, 11 Jan 2020 21:23:52 +0000

Don't keep Important informations as top level object key, cause then the client has to iterate through the object, find the key, relevent to him, at the same time discard the other irrelevant keys and then extract the data.

DO NOT PUT IMPORTANT DATA AS OBJECT KEYS

I faced this issue with my AI team, and had to spend a fuckload of time parsing the response

BAD RESPONSE DATA:

{
 "i_am_a_unique_id": 50
}

GOOD RESPONSE DATA

{
 "id": "i_am_a_unique_id",
 count: 50
}

Convert to JSON in Python vs Javascript

VICTOR OMONDI — Sat, 11 Jan 2020 21:19:01 +0000

Python:

import json

user = {
    "name": "Victor"
}

json_py = json.dumps(user)

Javascript:

const user = {
    name: "Victor"
}

const jsonJs = JSON.stringify(user);

Check if key exists in Dictionary/Object in Python vs Javascript

VICTOR OMONDI — Sat, 11 Jan 2020 21:16:07 +0000

Python

dict = { 'platform': 'telegram' }

if 'platform' in dict:
 # do something

Javascript

let obj ={ platform: 'telegram' }

if(obj['platform']){

   // do something

}

Docker Tip: To remove an image

VICTOR OMONDI — Sat, 11 Jan 2020 21:14:16 +0000

To remove an image try:

docker rmi <image_id/image_name>

DEV Community: VICTOR OMONDI

Basic Introduction To R

What is R?

How to Install and Getting Started With R

Table of Contents

Intro To R Basics

Hello, World!

Creating and Naming Variables

Rules for Naming Variables in R

R Arithmetic Operators

Comments

Basic Data Types in R

More Resources

Programs

Project Management, what is it?

What is A Project?

Key Terms to note.

1. Planning

2. Scheduling

3. Controlling.

Project Management

Agora Student Ambassador Program

Agora Student Ambassador Program

Program Benefits for SA

Top YouTube Channels to Learn AI/ML/RL/DS

Artificial Intelligence VS Data Science VS Machine Learning

Artificial Intelligence

Machine Learning

Data Science

Static methods in Python vs Javascript

Python

Javascript

Thing to note

In python if we declare a static method it can be called by both the class and by any of the instances (objects) created from the class ✔️✔️✔️

Javascript: Printing Object in Console

Javascript Devtool Tip: Print An Array in Console

API Design Tip

BAD RESPONSE DATA:

GOOD RESPONSE DATA

Convert to JSON in Python vs Javascript

Python:

Javascript:

Check if key exists in Dictionary/Object in Python vs Javascript

Python

Javascript

Docker Tip: To remove an image