When Your Model Is Inaccurate

Let's imagine you're doing research on an ideal rental property.  You gather your data, open up your favorite programming environment and you get to work on perform Exploratory Data Analysis (EDA).  During your EDA, you find some dirty data and clean it to train on.  You decide on a model, separate the data into training, validation, and testing, and train your model on the cleaned data.  Upon evaluating your model using some validation and test data, you notice that your validation error is very high as well as your test error.

Now suppose you pick a different model or add additional features.  Now your validation error is much lower.  Great!  However, upon using your testing data, you notice that the error is still high.  What just happened?

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What are Neural Networks?

I admit, I'm late to the whole Neural Network party.  With all of the major news covering AI that use neural network as part of their implementation, you'd have to be living under a rock to not know about them.  While it's true that they can provide more flexible models compared to the other machine learning algorithms, they can be challenging to work with.

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Setting up OpenCV for Java via Maven

When you learn about OpenCV, you'll often hit up on OpenCV for Python or C++, but not Java.  I can understand that OpenCV is a glorified NumPy extension for Python and OpenCV C++ is very fast.  However, it's possible that you have a legit need to use Java instead of Python or C++.

In a professional setting, Java users are likely to use Apache Maven to allow everyone to get the same version of each software without causing build and run issues.  Sure, you can always install the library and setup the CLASSPATH to point at OpenCV, but I find it better to use Maven to handle the libraries.  Just note that there is no official Maven repository for OpenCV at the time of writing, but there been others that have uploaded alternative repositories.

Repository for OpenCV 2

For those that are using OpenCV 2 and Java, you'd want to use the nu.pattern repository.  Here is the line of code needed to import OpenCV:

<!-- https://mvnrepository.com/artifact/nu.pattern/opencv -->

Repository for OpenCV 3

For those needing to use OpenCV 3, the repository will be different.  There is no nu.pattern equivalent version for OpenCV 3.  You will need to use the following repository instead:

<!-- https://mvnrepository.com/artifact/org.openpnp/opencv -->

Repository for OpenCV 4

Yes.  There will be an OpenCV 4 being released soon.  As a result, don't expect one for OpenCV 4 just yet.  If you're interested in installing an early release of OpenCV 4 for Python, Adrien Rosebrock has posted some instructions for Mac OS X and Ubuntu users.

Loading the OpenCV Library

After adding the repository to your Maven file, you need to load the library for use.  Normally, you would use the line:


However, this method won't work as it relies on the OpenCV libraries actually being installed.  Instead, you need to do the following:

nu.pattern.OpenCV.loadLocally(); // Use in case loadShared() doesn't work

Once you call one of these methods, you should be able to use OpenCV normally.  OpenCV Java is akin to OpenCV C++, so you should be able to transfer some of the knowledge over to the other programming language.

Sport Recommendation Exercise

Sports.  Sports.  Sports.

Some people love watching them.  Others love playing them.  The US love their football while those in Latin America love their soccer.  As much as we fight and bicker about which sport is the best or that our favorite team is the best, many people love sports as a pastime and follow their teams religiously.

While I'm not a sports fan, I did come across an interesting dataset from data.world that determine what was the toughest sport to pick up.  Even though this dataset is framed in an objective manner, I would like to ask a different question: Based on the sports data and a person's abilities, what sport would be optimal for them?

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Overview of Apache Spark

For those wanting to work with Big Data, it isn't enough to simply know a programming language and a small scale library.  Once your data reaches many gigabytes, if not terabytes,  in size, working with data becomes cumbersome.  Your computer can only run so fast and store only so much.  At this point, you would look into what kind of tooling is used for massive amounts of data.  One of the tools that you would consider is called Apache Spark.  In this post, we'll look at what is Spark, what can we do with Spark, and why to use Spark.

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The Interview Attendance Problem - Data Cleaning

One of the recent datasets that I picked up was a Kaggle dataset called "The Interview Attendance Problem".  This dataset focuses on job candidates in India attending interviews for several different companies across a few different industries.  The objective is to determine whether a job candidate will be likely to show up or not.

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Popular Kaggle Kernels dataset

With Data Science being a very popular field that people want to get into, it's no surprise that the amount of contributions to Kaggle dramatically increased.  I recently stumbled across a dataset that gathered the most popular kernels and decided to do some exploratory data analysis on the dataset.

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Kaggle's Digit Recognizer dataset

One of the hottest tech disciplines in 2017 in the tech industry was Deep Learning.  Due to Deep Learning, many startups placed AI emphasis and many frameworks have been developed to make implementing these algorithms easier.  Google's DeepMind was even able to create AlphaGo Zero that didn't rely on data to master the game of Go.  However, the analysis is much more basic than anything that was recently developed.  In fact, the dataset is the popular MNIST database dataset.  In other words, the dataset consists of hand written digits to test out computer vision.

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Coursera now offers Deep Learning

For those interested in machine learning, Dr. Andrew Ng recently launched his new Coursera specialization course called Deep Learning.  Be prepared to have some Python experience.

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Dataset: Paradis Bilingual Corpus

It's been a while since I last did an analysis on a dataset.  Today's dataset will focus on a corpus that deals with children learning English as a second language.  The study was done by Johanne Paradis from the University of Alberta.

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