Start your free trial now, and begin learning software, business and creative skills—anytime, anywhere—with video instruction from recognized industry experts.

Start Your Free Trial Now

Introducing Lake Pend Oreille


Code Clinic: PHP

with David Powers

Video: Introducing Lake Pend Oreille

Introducing Lake Pend Oreille provides you with in-depth training on Developer. Taught by David Powers as part of the Code Clinic: PHP
Expand all | Collapse all
  1. 8m 49s
    1. Welcome
      1m 18s
    2. What you should know before watching this course
      4m 40s
    3. Using the exercise files
      1m 56s
    4. Getting the most from Code Clinic
  2. 1h 34m
    1. Introducing Lake Pend Oreille
      5m 4s
    2. Overview of my solution
      3m 22s
    3. Setting up the database
      4m 55s
    4. Retrieving the full-year records
      5m 20s
    5. Processing the full-year records
      10m 49s
    6. Priming the date_recorded column
      7m 47s
    7. Inserting the full-year data into the database
      6m 48s
    8. Processing individual days
      6m 54s
    9. Retrieving a year's data a day at a time
      7m 41s
    10. Keeping the data up to date
      4m 27s
    11. Calculating the mean and median values
      7m 21s
    12. Creating a web service
      6m 21s
    13. Getting the required data
      6m 50s
    14. Building the web service response
      10m 38s
  3. 49m 47s
    1. Identify the image subset
      3m 14s
    2. Overview of my solution
      3m 19s
    3. Setting up the files
      2m 43s
    4. Calculating the scaling ratio
      6m 28s
    5. Using a custom class to scale images
      6m 25s
    6. Generating the thumbnails
      7m 49s
    7. Using subimage-search in ImageMagick
      4m 32s
    8. Analyzing the image statistics
      4m 45s
    9. Finding the cropped images
      7m 13s
    10. Running the script and displaying the results
      3m 19s
  4. 39m 3s
    1. A classic CS interview question
      2m 4s
    2. Overview of my solution
      3m 48s
    3. Finding all possible combinations
      6m 26s
    4. Detecting horizontal attacks programmatically
      4m 8s
    5. Implementing the checkLayout() function
      6m 25s
    6. Rotating the chessboard
      4m 59s
    7. Eliminating duplicate solutions
      6m 34s
    8. Displaying the unique solutions
      4m 39s
  5. 21m 33s
    1. Build a musical instrument using mouse movements
      1m 35s
    2. Overview of my solution
      2m 1s
    3. Using the Web Audio API
      2m 47s
    4. Creating the tone generator
      7m 39s
    5. Controlling the frequency and volume
      7m 31s
  6. 31m 29s
    1. Searching directories for photos
      2m 44s
    2. Overview of my solution
      3m 24s
    3. Finding the images
      5m 30s
    4. Extracting Exif and IPTC metadata
      6m 18s
    5. Extracting XMP metadata
      6m 22s
    6. Reorganizing the folder structure
      7m 11s
  7. 39m 41s
    1. Building the web
      1m 47s
    2. Overview of my solution
      1m 50s
    3. Getting data from a CSV file: The basics
      4m 29s
    4. Automatically generating an HTML table from a CSV file
      7m 48s
    5. Displaying the table in a webpage
      6m 26s
    6. Creating an associative array from a CSV file
      3m 55s
    7. Displaying the array elements in a webpage
      6m 30s
    8. Dealing with different CSV formats
      6m 56s

please wait ...
Introducing Lake Pend Oreille
Video Duration: 5m 4s4h 44m Intermediate Jul 15, 2014 Updated Dec 16, 2014

Viewers: in countries Watching now:

Introducing Lake Pend Oreille provides you with in-depth training on Developer. Taught by David Powers as part of the Code Clinic: PHP

View Course Description

Many successful programmers know more than just a computer language. They also know how to think about solving problems. They use "computational thinking": breaking a problem down into segments that lend themselves to technical solutions. Code Clinic is a series of six courses where authors solve the same problems using different programming languages. Here, David Powers works with PHP.

David introduces challenges and provides an overview of his solutions in PHP. Challenges include topics such as statistical analysis, searching directories for images, and accessing peripheral devices.

Visit other courses in the series to see how to solve the exact same challenges in languages like C#, C++, Java, Python, and Ruby.

David Powers

Introducing Lake Pend Oreille

Hello, and welcome to Code Clinic. My name is David Powers. Code Clinic is a monthly course where unique a problem is introduced to a collection of authors. In response, each author creates a solution, using the programming language of their choice. In my case, I'll be using PHP. You can learn several things from Code Clinic. Different approaches to solving the problem, the pros and cons of different languages, and some tips and tricks to incorporate into your own coding practices.

This month, we'll work on a problem in statistical analysis and to some extent, handling big data. It's common to use a computer to manipulate and summarize large amounts of information, providing important insights into how to improve or handle a situation. In this problem, we'll use weather data collected by the US Navy from Lake Pend Oreille in northern Idaho. Lake Pend Oreille is the fifth deepest fresh water lake in the United States. So deep in fact, that the US Navy uses it to test submarines.

As part of that testing, the US Navy compiles an exhaustive list of weather statistics, including wind speed, air temperature and barometric pressure. You can browse this data by pointing your browser at You'll find several weather summaries, a web cam, and the raw data they collect every five or six minutes archived as standard text files.

For anyone living or working on Lake Pend Oreille, weather statistics are an important part of every day life. Especially if you're on a small boat in the middle of the lake. There can be a significant difference between average wind speed and median wind speed.In this challenge I'll be using PHP to calculate the mean and median of the wind speed, air temperature and barometric pressure recorded into the Deep Moor station for a given range of dates. The other authors will each use their own favorite language to solve the same problem.

First, let's briefly review mean and median. These are both statistics, to explain how they're calculated, we need a set of numbers. How about 14 readings for Wind Gusts at Deep Moor weather station on January 1, 2014. You can see the data of this website. The first column, is the day the wind gust was recorded. The second column, is the time it was recorded. And the third column, is the wind gust in miles per hour. The mean, is also known as the average.

So calculate the mean of a range of numbers, simply add the values in the set and then divide by the number of values. In this example, we add all of these numbers together and then divide the sum by 14 the amount of numbers in the set. In this case, the mean is equal to nine. The median is the middle value in a set of data sorted in ascending order. Think of the median as the median strip of the road, it always marks the center.

To calculate the median first, sort the numbers from lowest to highest. If there's an odd number of values, then just take the middle number. If there's an even number of values, then calculate the average of the central two numbers. In this case, there's an even number of values. So we sort, then take the average of the middle two values, eight and eleven, so the median is 9.5. In addition, some offices including myself have chosen to implement a web service to provide access to the new weather statistics created by the author's program.

This is typically done by creating a RESTful API, which when called, returns information in a format known as JSON. For a detailed description of JSON and its uses please, refer to JavaScript and JSON by Ray Villalobos. If you make this http call to my website of, you would expect to receive the mean and median for wind speed, air temperature, and barometric pressure for the range of dates starting from March 19, 2011, and running until midnight of the following day.

The JSON data returned looks like this. So that is our first challenge. Pull statistics from a data set available online. Perhaps, you want to pause and create a solution of your own. How would you solve the problem? In the next videos, I'll show you how I solve the challenge

Find answers to the most frequently asked questions about Code Clinic: PHP .

Expand all | Collapse all
please wait ...
Q: I'm encountering script errors message with the prime_dates.php file used in the "Priming the date_record column" movie in this course. How can I resolve these errors?
A: To avoid script errors, use bindValue() instead of bindParam() in Line 9 of the prime_dates.php file. You can also download the latest copy of the exercise files, which corrects this issue for you. For a more in-depth explanation of the difference between bindValue() and bindParam(), check out the "Binding input and output values" video ( in Accessing Databases with Object-Oriented PHP.
Q: Why can't I access the Lake Pend Orielle site (

A: The Lake Pend Orielle site is not accessible in some geographical areas. We have contacted the owner of the server to try to resolve this issue.

Q: I am unable to access the Lake Pend Oreille data from outside the U.S.
A: A static copy of this data is provided here for members outside of the U.S
Share a link to this course

What are exercise files?

Exercise files are the same files the author uses in the course. Save time by downloading the author's files instead of setting up your own files, and learn by following along with the instructor.

Can I take this course without the exercise files?

Yes! If you decide you would like the exercise files later, you can upgrade to a premium account any time.

Become a member Download sample files See plans and pricing

Please wait... please wait ...
Upgrade to get access to exercise files.

Exercise files video

How to use exercise files.

Learn by watching, listening, and doing, Exercise files are the same files the author uses in the course, so you can download them and follow along Premium memberships include access to all exercise files in the library.

Exercise files

Exercise files video

How to use exercise files.

For additional information on downloading and using exercise files, watch our instructional video or read the instructions in the FAQ .

This course includes free exercise files, so you can practice while you watch the course. To access all the exercise files in our library, become a Premium Member.

* Estimated file size

Are you sure you want to mark all the videos in this course as unwatched?

This will not affect your course history, your reports, or your certificates of completion for this course.

Mark all as unwatched Cancel


You have completed Code Clinic: PHP.

Return to your organization's learning portal to continue training, or close this page.


Upgrade to View Courses Offline


With our new Desktop App, Annual Premium Members can download courses for Internet-free viewing.

Upgrade Now

After upgrading, download Desktop App Here.

Become a member to add this course to a playlist

Join today and get unlimited access to the entire library of video courses—and create as many playlists as you like.

Get started

Already a member ?

Exercise files

Learn by watching, listening, and doing! Exercise files are the same files the author uses in the course, so you can download them and follow along. Exercise files are available with all Premium memberships. Learn more

Get started

Already a Premium member?

Exercise files video

How to use exercise files.

Ask a question

Thanks for contacting us.
You’ll hear from our Customer Service team within 24 hours.

Please enter the text shown below:

Exercise files

Access exercise files from a button right under the course name.

Mark videos as unwatched

Remove icons showing you already watched videos if you want to start over.

Control your viewing experience

Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.

Interactive transcripts

Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.

Learn more, save more. Upgrade today!

Get our Annual Premium Membership at our best savings yet.

Upgrade to our Annual Premium Membership today and get even more value from your subscription:

“In a way, I feel like you are rooting for me. Like you are really invested in my experience, and want me to get as much out of these courses as possible this is the best place to start on your journey to learning new material.”— Nadine H.

Start your FREE 10-day trial

Begin learning software, business, and creative skills—anytime,
anywhere—with video instruction from recognized industry experts. provides
Unlimited access to over 4,000 courses—more than 100,000 video tutorials
Expert-led instruction
On-the-go learning. Watch from your computer, tablet, or mobile device. Switch back and forth as you choose.
Start Your FREE Trial Now

A trusted source for knowledge.


We provide training to more than 4 million people, and our members tell us that helps them stay ahead of software updates, pick up brand-new skills, switch careers, land promotions, and explore new hobbies. What can we help you do?

Thanks for signing up.

We’ll send you a confirmation email shortly.

Sign up and receive emails about and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from

Sign up and receive emails about and our online training library:

Here’s our privacy policy with more details about how we handle your information.

submit Lightbox submit clicked
Terms and conditions of use

We've updated our terms and conditions (now called terms of service).Go
Review and accept our updated terms of service.