Programming the Web with Ruby

Registrations are now open for RubyLearning’s “Pay if you like”, online course on “Programming the Web with Ruby“. The first batch had over 2000 participants. Web-based applications offer many advantages, such as instant access, automatic upgrades, and opportunities for collaboration on a massive scale. However, creating Web applications requires different approaches than traditional applications and involves the integration of numerous technologies. The course topics would hopefully help those that have some knowledge of Ruby programming to get started with web programming (this does not cover Ruby on Rails).

Who’s It For?

Anyone with some knowledge of Ruby programming.

Dates

The course starts on Saturday, 29th June 2013 and runs for 2 weeks.

Is the course really free?

A lot of effort and time goes into building such a course and we would really love that you pay at least US$ 15 for the course. Since this is a “Pay if you Like” course, you are under no obligation to pay and hence the course would be free for you.

For those who contribute US$ 15, we shall email them a copy of the book (.pdf) “Programming the Web with Ruby” – the course is based on this book.

How do I register and pay the course fees?

• First, create an account on the site and then pay the fees of US$ 15 by clicking on the PayPal button
• After payment of the fees please send us your name to satish [at] rubylearning [dot] org so that we can send you the eBook, which normally takes place within 48 hours.
• If you want to take the course for free, please just create an account and send us your name (as mentioned above).

Course Contents

• Using Git
• Using GitHub
• Using RVM (for *nix)
• Using pik (for Windows)
• Using bundler
• Using Heroku
• Creating a simple webpage using HTML5, CSS and JavaScript
• Store your webpage files on GitHub
• Understanding HTTP concepts
• Using cURL
• net/http library
• Using URI
• Using open-uri
• Using Nokogiri
• Creating one’s own Ruby Gem
• Learning Rack
• Deploying Pure Rack Apps to Heroku
• Deploying a static webpage to Heroku
• What’s JSON?
• Using MongoDB with Ruby Mongo driver
• MongoHQ the hosted database
• Using Sinatra
• Deploying Sinatra apps to Heroku
• Sinatra and SQLite3 interaction

The course contents are subject to change.

Mentors

Satish Talim, Victor Goff III, Michele Garoche and others from the RubyLearning team.

RubyLearning’s IRC Channel

Mentors and students hang out at RubyLearning’s IRC (irc.freenode.net) channel (#RubyLearning.org) for both technical and non-technical discussions. Everyone benefits with the active discussions on Ruby with the mentors.

Here are some details on how the course works:

Important:

Once the course starts, you can login and start with the lessons any day and time and post your queries in the forum under the relevant lessons. Just to set the expectations correctly, there is no real-time ‘webcasting’.

Methodology:

• The Mentors shall give you URL’s of pages and sometimes some extra notes; you need to read through. Read the pre-class reading material at a convenient time of your choice – the dates mentioned are just for your guideline. While reading, please make a note of all your doubts, queries, questions, clarifications, comments about the lesson and after you have completed all the pages, post these on the forum under the relevant lesson. There could be some questions that relate to something that has not been mentioned or discussed by the mentors thus far; you could post the same too. Please remember that with every post, do mention the operating system of your computer.
• The mentor shall highlight the important points that you need to remember for that day’s session.
• There could be exercises every day. Please do them.
• Participate in the forum for asking and answering questions or starting discussions. Share knowledge, and exchange ideas among yourselves during the course period. Participants are strongly encouraged to post technical questions, interesting articles, tools, sample programs or anything that is relevant to the class / lesson. Please do not post a simple "Thank you" note or "Hello" message to the forum. Please be aware that these messages are considered noises by people subscribed to the forum.

Outline of Work Expectations:

1. Most of the days, you will have exercises to solve. These are there to help reinforce what you have just learned.
2. Some days may have some extra assignments / food for thought articles / programs.
3. Above all, do take part in the relevant forums. Past participants have confirmed that they learned the best by active participation.

Some Commonly Asked Questions

• Qs. Is there any specific time when I need to be online?
  Ans. No. You need not be online at a specific time of the day.
• Qs. Is it important for me to take part in the course forums?
  Ans. YES. You must Participate in the forum(s) for asking and answering questions or starting discussions. Share knowledge, and exchange ideas among yourselves (participants) during the course period. Participants are strongly encouraged to post technical questions, interesting articles, tools, sample programs or anything that is relevant to the class / lesson. Past participants will confirm that they learned the best by active participation.
• Qs. How much time do I need to spend online for a course, in a day?
  Ans. This will vary from person to person. All depends upon your comfort level and the amount of time you want to spend on a particular lesson or task.
• Qs. Is there any specific set time for feedback (e.g., any mentor responds to me within 24 hours?)
  Ans. Normally somebody should answer your query / question within 24 hours.
• Qs. What happens if nobody answers my questions / queries?
  Ans. Normally, that will not happen. In case you feel that your question / query is not answered, then please post the same in the thread – “Any UnAnswered Questions / Queries”.
• Qs. What happens to the class (or forums) after a course is over? Can you keep it open for a few more days so that students can complete and discuss too?
  Ans. The course and its forum is open for a month after the last day of the course.

Remember, the idea is to have fun learning Ruby.

Acknowledgments

• Al Snow for his various suggestions.
• Arvinder Singh Kang for the note on “Using RVM”
• Konstantin Haase for providing us with another practical Rack app.
• Matt Aimonetti for the GET/POST example related to Rack.
• Michael Kohl for proof reading and making relevant corrections to day 1 and 2 material.
• Oto Brglez for the note on “Using Nokogiri”
• Samnang Chhun for suggesting changes in day 1 material.
• Victor Goff for his various suggestions.
• Willian Molinari for creating the GitHub page for this project.
• Zhang Hailong for making relevant corrections in day 2 material.

About RubyLearning.org

RubyLearning.org, since 2005, has been helping Ruby Newbies go from zero to awesome!

Registrations are now open for RubyLearning’s popular Ruby programming course. This is an intensive, online course for beginners that helps you get started with Ruby programming.

Course Fee

• US$ 49.95 for the first 5 participants
• US$ 63.95 for the next 10 participants
• US$ 79.95 after the first 15 participants

Please pay by clicking on the PayPal button

---

Download ‘Advice for Ruby Beginners’ as a .zip file.

Here is what Demetris Demetriou, a participant who just graduated, has to say – “When I joined this course I was sceptical about how useful this course would be for me instead of reading material and watching videos on YouTube and thus saving money. After the course started I realised how valuable this course was. In the past I had read many Ruby books over and over, but never got into really getting practical with it and never had confidence in it. Lots of theory but couldn’t use it. I feel that the exercises in this course and the support, monitoring from our mentor Victor, made the huge difference that all books in the past didn’t. It wasn’t about reading lots of books, but simply few things and get practical and understand them well. I feel I learnt a lot and I’m coming back for more to rubylearning.org Thanks a lot Victor and Satish and all the other Rubyists who gave us today’s Ruby.”

What’s Ruby?

According to http://www.ruby-lang.org/en/ – “Ruby is a dynamic, open source programming language with a focus on simplicity and productivity. Ruby’s elegant syntax is natural to read and easy to write.”

Yukihiro Matsumoto, the creator of Ruby, in an interview says -

I believe people want to express themselves when they program. They don’t want to fight with the language. Programming languages must feel natural to programmers. I tried to make people enjoy programming and concentrate on the fun and creative part of programming when they use Ruby.

What Will I Learn?

In the Ruby programming course, you will learn the essential features of Ruby that you will end up using every day. You will also be introduced to Git, GitHub, HTTP concepts, RubyGems, Rack and Heroku.

Depending on participation levels, we throw a Ruby coding challenge in the mix, right for the level we are at. We have been known to give out a prize or two for the ‘best’ solution.

Who’s It For?

A beginner with some knowledge of programming.

You can read what past participants have to say about the course.

• Testimonials
• Natasha Murashev
• Melanie Shebel
• Katerina Jackson-Suchkova
• Mani Maran M

Mentors

Satish Talim, Michael Kohl, Satoshi Asakawa, Victor Goff III and others from the RubyLearning team.

Dates

The course starts on Saturday, 18th May 2013 and runs for seven weeks.

RubyLearning’s IRC Channel

Most of the mentors and students hang out at RubyLearning’s IRC (irc.freenode.net) channel (#rubylearning.org) for both technical and non-technical discussions. Everyone benefits with the active discussions on Ruby with the mentors.

How do I register and pay the course fees?

• The course is based on the The Ultimate Guide to Ruby Programming eBook. This book is priced at US$ 9.95
• You can pay either by Paypal or send cash via Western Union Money Transfer or by bank transfer (if you are in India). The fees collected helps RubyLearning maintain the site, this Ruby course, the Ruby eBook, and provide quality content to you.

The Course Fee is:

• US$ 49.95 for the first 5 participants
• US$ 63.95 for the next 10 participants
• US$ 79.95 after the first 15 participants

Please pay by clicking on the PayPal button

At the end of this course you should have all the knowledge to explore the wonderful world of Ruby on your own.

Here are some details on how the course works:

Important:

Once the course starts, you can login and start with the lessons any day and time and post your queries in the forum under the relevant lessons. Someone shall always be there to answer them. Just to set the expectations correctly, there is no real-time ‘webcasting’.

Methodology:

• The Mentors shall give you URL’s of pages and sometimes some extra notes; you need to read through. Read the pre-class reading material at a convenient time of your choice – the dates mentioned are just for your guideline. While reading, please make a note of all your doubts, queries, questions, clarifications, comments about the lesson and after you have completed all the pages, post these on the forum under the relevant lesson. There could be some questions that relate to something that has not been mentioned or discussed by the mentors thus far; you could post the same too. Please remember that with every post, do mention the operating system of your computer.
• The mentor shall highlight the important points that you need to remember for that day’s session.
• There could be exercises every day. Please do them.
• Participate in the forum for asking and answering questions or starting discussions. Share knowledge, and exchange ideas among yourselves during the course period. Participants are strongly encouraged to post technical questions, interesting articles, tools, sample programs or anything that is relevant to the class / lesson. Please do not post a simple "Thank you" note or "Hello" message to the forum. Please be aware that these messages are considered noises by people subscribed to the forum.

Outline of Work Expectations:

1. Most of the days, you will have exercises to solve. These are there to help you assimilate whatever you have learned till then.
2. Some days may have some extra assignments / food for thought articles / programs
3. Above all, do take part in the relevant forums. Past participants will confirm that they learned the best by active participation.

Some Commonly Asked Questions

• Qs. Is there any specific time when I need to be online?
  Ans. No. You need not be online at a specific time of the day.
• Qs. Is it important for me to take part in the course forums?
  Ans. YES. You must Participate in the forum(s) for asking and answering questions or starting discussions. Share knowledge, and exchange ideas among yourselves (participants) during the course period. Participants are strongly encouraged to post technical questions, interesting articles, tools, sample programs or anything that is relevant to the class / lesson. Past participants will confirm that they learned the best by active participation.
• Qs. How much time do I need to spend online for a course, in a day?
  Ans. This will vary from person to person. All depends upon your comfort level and the amount of time you want to spend on a particular lesson or task.
• Qs. Is there any specific set time for feedback (e.g., any mentor responds to me within 24 hours?)
  Ans. Normally somebody should answer your query / question within 24 hours.
• Qs. What happens if nobody answers my questions / queries?
  Ans. Normally, that will not happen. In case you feel that your question / query is not answered, then please post the same in the thread – “Any UnAnswered Questions / Queries”.
• Qs. What happens to the class (or forums) after a course is over? Can you keep it open for a few more days so that students can complete and discuss too?
  Ans. The course and its forum is open for a month after the last day of the course.

Remember, the idea is to have fun learning Ruby.

A FREE Git and GitHub Course – 8th batch

Registrations are now open for RubyLearning’s popular Git and GitHub course. This is an introductory but an intensive, online course for beginners. Here you’ll learn the essential features of both Git and GitHub that you’ll end up using every day.

What’s Git and GitHub?

Git is an open source version control system designed to handle very large projects with speed and efficiency, but just as well suited for small personal repositories (collection of resources that can be accessed to retrieve information); it is especially popular in the open source community. With GitHub you can host your public and private projects there and use it to collaborate on projects.

Ruby Master, Josh Susser¹ in an interview with RubyLearning said:

First off, get an account on GitHub. (If you haven’t learned git yet, get going on that too – it’s the future for open source SCM.) Then do some exploring around the various projects and see where you think you can jump in and contribute something. Pick a project that is currently under development and has an active community. You’ll have enough going on that you don’t want to be championing a project just yet.

Get involved in the Ruby community. Join GitHub

What Will I Learn?

The course topics in brief are:

• What’s Version Control
• What’s Git
• Downloading and Installing Git
• Create your SSH Key
• Introduce yourself to Git
• Add some additional Git settings
• What’s GitHub?
• Set up your GitHub account
• Follow a Friend
• Watch projects
• Creating a new repository
• Deleting and renaming repositories
• Fork a repository
• Push changes to a repository
• Clone a public project
• Add collaborators to a project
• Collaborate with other users
• Send a pull request
• Merge changes from a pull request
• Use project wikis
• Create and delete branches and tags
• Create GitHub pages
• Gist
• Exercises

Who’s It For?

The Git and GitHub course is a starting point for people new to Git and GitHub, to learn it as quickly and easily as possible.

Dates

The course starts on 4th May 2013 and runs for a week.

The first seven batches were a run-away success. So hurry, registrations have started.

Is the course really free?

A lot of effort and time goes into building such a course and we would really love that you pay at least US$ 5 for the course. Since this is a “Pay if you Like” course, you are under no obligation to pay anything at all and hence the course would be free for you. For those who contribute US$ 5 or more, we shall email them a copy of the book (.pdf) “Using Git & GitHub eBook” – the course is based on this book.

How do I register?

• For the “Free” participants, register on the RubyLearning.org site and send us your name and registered email address while creating an account at RubyLearning.org to satish [at] rubylearning [dot] org We will enroll you into the course which normally takes place within 48 hours.
• For those who want to contribute, you can pay either by Paypal or send cash via Western Union Money Transfer or by bank transfer (if you are in India). The fees collected helps RubyLearning maintain the site, the various courses and provide quality content to you.
• Once you pay the fees below, register on the RubyLearning.org site and send us your name and registered email address while creating an account at RubyLearning.org to satish [at] rubylearning [dot] org We will enroll you into the course which normally takes place within 48 hours.

After you click the “Pay Now” button below, you will be taken to a webpage as shown below.

Please enter the amount you want to pay for the course in the “Item price” field and click on the “Update” link. You can safely pay via PayPal.

You can now pay the Course Fees by clicking on the “Pay Now” button below.

Ruby Matrix, the Forgotten Library

This guest post is contributed by Matthew Kirk, who is a partner at Modulus 7, specializing in software development and strategy. The basis of his career has been around utilizing science to improve businesses. He has spoken at technology conferences around the world and in his spare time, he enjoys traveling and adding to his 2000+ vinyl record collection.

Remember matrices from math class? No not the movie, but the rectangular array of numbers. While you might not see it often, Ruby has a matrix implementation that is well tested and allows you to accomplish tough calculations quickly.

While I won’t be able to teach you everything there is to be known about matrices, we will cover how to use matrices within Ruby as well as some quirks and their major selling points. By the end of this I hope that you delve deeper into learning about matrices and use them in your next project.

What are matrices?

A matrix according to Wikipedia is a rectangular array of numbers. Used heavily in math, matrices are all over languages like R and Matlab. They can be a great way to store numerical data and simplify many difficult and tedious problems. Instead of solving systems of equations matrices can simplify these into one equation.

In terms of how Ruby implements matrices, Ruby stores all matrix rows into one big array. The only requirement is that the arrays are of the same dimension. So for each row that is added to a matrix each one must be of the same size.

Just like arrays, matrices are zero indexed meaning that the first row is index 0 and the first column is index 0. Unlike arrays though you have to have two indexes to get to an element:

Making matrices:

Some quirks:

The Matrix library has some quirks. The Matrix class allows non-numerical data to go into itself. This could be useful for storing things like symbols in a more x, y format but render most of the matrix functions useless.

For instance:

Another quirk to be aware of: Matrix[*rows] does not copy the rows objects but instead points to it. To avoid this use Matrix.rows(rows) or Matrix.columns(columns). Implementation wise Matrix[*rows] calls the function Matrix.rows(rows, copy = false).

Iterating over matrices:

How do you iterate over a matrix? Most likely you would think that matrices read left to right top to bottom. And that’s true. But there are other cases as well.

In total there are 7 ways to iterate over a Matrix in ruby:

• :all This reads left to right top to bottom. This is the default case when you type matrix.each
• :diagonal: This only reads the diagonal elements or row index == column index
• :off_diagonal: This will read everything not on the diagonal or row index != column index
• :lower: This reads the lower triangle of the matrix or row index <= column index
• :strict_lower: this is more strict and reads only row index < column index
• :strict_upper: this is a strict upper triangle and is row index > column index
• :upper: row index >= column index

An example:

Example: Parabola with matrix:

Imagine you want to fit a curve through three points. If you remember math class you might remember that you can do this by fitting a quadratic. For instance lets say we want a line that goes through (1,2) (3, 5.5) and (6, 6). To solve this we would write the equations:

The way to solve this would usually involve lots of algebra and substitutions. While it’s easy to solve this in the case where we already know the numbers it is difficult to come up with a general solution (try it I dare you).

Instead of worrying about solving this using non-matrix algebra we can solve it using matrix algebra. The first step is to rewrite the above system into this form:

To make it even easier to solve we would rewrite this as Ax = b. To solve this we would take the inverse of A and then multiply both sides by that. Which would yield:

Now that we know this, we can easily solve this using Ruby with the following formula.

While it’s close it won’t be correct unless you use Rational. Ruby’s matrix library graciously utilizes functions that preserve precision. You would expect most libraries to convert to floats but ruby does not.

For instance you can change the above function call to:

Whenever possible try to preserve the precision!

The general case, fitting an n-power polynomial to n points:

Up above we only fit this curve to 3 points. But what about 4 or 15 points? This would be quite simple to do and would only require a little bit of modification:

Conclusion:

While you might not use matrices every day, they can be useful to solve problems involving systems of equations. Ruby has a robust matrix library that can be useful in finding solutions to these types of problems. Next time you want to fit a curve keep in mind matrices might be the best way to go!

For more information about matrices I recommend reading Wikipedia articles. There are lots of math professors who spend hours updating them tediously. If they are too confusing, think about picking up a book on matrix algebra like Matrix Computations.

Feel free to ask questions and give feedback in the comments section of this post. Thanks!

Programming for the Web with Ruby

Registrations are now open for RubyLearning’s FREE (Pay if you like), online course on “Programming for the Web with Ruby“. The previous batch had over 2000 participants. Web-based applications offer many advantages, such as instant access, automatic upgrades, and opportunities for collaboration on a massive scale. However, creating Web applications requires different approaches than traditional applications and involves the integration of numerous technologies. The course topics would hopefully help those that have some knowledge of Ruby programming to get started with web programming (this does not cover Ruby on Rails).

Who’s It For?

Anyone with some knowledge of Ruby programming.

Dates

The course starts on Saturday, 16th Mar. 2013 and runs for 2 weeks.

Is the course really free?

A lot of effort and time goes into building such a course and we would really love that you pay at least US$ 10 for the course. Since this is a “Pay if you Like” course, you are under no obligation to pay anything at all and hence the course would be free for you. For those who contribute US$ 10 or more, we shall email them a copy of the book (.pdf) “Programming the Web with Ruby” – the course is based on this book.

How do I register and pay the course fees?

• If you want to take the course for free, please create an account at rubylearning.org and send us at satish [at] rubylearning.org – the email address with which you have registered.
• Those of you who want to help RubyLearning maintain the site, the various courses and provide quality content, you can pay either by Paypal or send cash via Western Union Money Transfer or by bank transfer (if you are in India).
• Once you pay the fees below, register on the RubyLearning.org site and send us your name and registered email id while creating an account at RubyLearning.org to satish [at] rubylearning [dot] com We will enrol you into the course which normally takes place within 48 hours.

After you click the “Pay Now” button below, you will be taken to a webpage as shown below.

Please enter the amount you want to pay for the course in the “Item price” field and click on the “Update” link. You can safely pay via PayPal.

You can now pay the Course Fees by clicking on the “Pay Now” button below.

Course Contents

• Using Git
• Using GitHub
• Using RVM (for *nix)
• Using pik (for Windows)
• Using bundler
• Using Heroku
• Creating a simple webpage using HTML5, CSS and JavaScript
• Store your webpage files on GitHub
• Understanding HTTP concepts
• Using cURL
• net/http library
• Using URI
• Using open-uri
• Using Nokogiri
• Creating one’s own Ruby Gem
• Learning Rack
• Deploying Pure Rack Apps to Heroku
• Deploying a static webpage to Heroku
• What’s JSON?
• Using MongoDB with Ruby Mongo driver
• MongoHQ the hosted database
• Using Sinatra
• Deploying Sinatra apps to Heroku
• Sinatra and SQLite3 interaction

The course contents are subject to change.

Mentors

Satish Talim, Victor Goff III, Michele Garoche and others from the RubyLearning team.

RubyLearning’s IRC Channel

Mentors and students hang out at RubyLearning’s IRC (irc.freenode.net) channel (#RubyLearning.org) for both technical and non-technical discussions. Everyone benefits with the active discussions on Ruby with the mentors.

Here are some details on how the course works:

Important:

Once the course starts, you can login and start with the lessons any day and time and post your queries in the forum under the relevant lessons. Just to set the expectations correctly, there is no real-time ‘webcasting’.

Methodology:

• The Mentors shall give you URL’s of pages and sometimes some extra notes; you need to read through. Read the pre-class reading material at a convenient time of your choice – the dates mentioned are just for your guideline. While reading, please make a note of all your doubts, queries, questions, clarifications, comments about the lesson and after you have completed all the pages, post these on the forum under the relevant lesson. There could be some questions that relate to something that has not been mentioned or discussed by the mentors thus far; you could post the same too. Please remember that with every post, do mention the operating system of your computer.
• The mentor shall highlight the important points that you need to remember for that day’s session.
• There could be exercises every day. Please do them.
• Participate in the forum for asking and answering questions or starting discussions. Share knowledge, and exchange ideas among yourselves during the course period. Participants are strongly encouraged to post technical questions, interesting articles, tools, sample programs or anything that is relevant to the class / lesson. Please do not post a simple "Thank you" note or "Hello" message to the forum. Please be aware that these messages are considered noises by people subscribed to the forum.

Outline of Work Expectations:

1. Most of the days, you will have exercises to solve. These are there to help reinforce what you have just learned.
2. Some days may have some extra assignments / food for thought articles / programs.
3. Above all, do take part in the relevant forums. Past participants have confirmed that they learned the best by active participation.

Some Commonly Asked Questions

• Qs. Is there any specific time when I need to be online?
  Ans. No. You need not be online at a specific time of the day.
• Qs. Is it important for me to take part in the course forums?
  Ans. YES. You must Participate in the forum(s) for asking and answering questions or starting discussions. Share knowledge, and exchange ideas among yourselves (participants) during the course period. Participants are strongly encouraged to post technical questions, interesting articles, tools, sample programs or anything that is relevant to the class / lesson. Past participants will confirm that they learned the best by active participation.
• Qs. How much time do I need to spend online for a course, in a day?
  Ans. This will vary from person to person. All depends upon your comfort level and the amount of time you want to spend on a particular lesson or task.
• Qs. Is there any specific set time for feedback (e.g., any mentor responds to me within 24 hours?)
  Ans. Normally somebody should answer your query / question within 24 hours.
• Qs. What happens if nobody answers my questions / queries?
  Ans. Normally, that will not happen. In case you feel that your question / query is not answered, then please post the same in the thread – “Any UnAnswered Questions / Queries”.
• Qs. What happens to the class (or forums) after a course is over? Can you keep it open for a few more days so that students can complete and discuss too?
  Ans. The course and its forum is open for a month after the last day of the course.

Remember, the idea is to have fun learning Ruby.

Acknowledgments

• Al Snow for his various suggestions.
• Arvinder Singh Kang for the note on “Using RVM”
• Konstantin Haase for providing us with another practical Rack app.
• Matt Aimonetti for the GET/POST example related to Rack.
• Michael Kohl for proof reading and making relevant corrections to day 1 and 2 material.
• Oto Brglez for the note on “Using Nokogiri”
• Samnang Chhun for suggesting changes in day 1 material.
• Victor Goff for his various suggestions.
• Willian Molinari for creating the GitHub page for this project.
• Zhang Hailong for making relevant corrections in day 2 material.

About RubyLearning.org

RubyLearning.org, since 2005, has been helping Ruby Newbies go from zero to awesome!