Category Archives: Programming

Efficiency problems with using java.util.Hashmap

Today, I will talk about some efficiency problems when using the java.util.Hashmap data structure provided by Java. This is an important topics for programmers that aim at implementing efficient software that rely on maps. Brief review about HashMap First, let’s … Continue reading

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A Tribute to Hypercard

In this blog post, I will talk about the first programming language that I have learn, which is HyperTalk. Younger readers may have never heard about it, as it was mostly popular in the 1980s and 1990s. Though, it is not … Continue reading

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Introduction to the Apriori algorithm (with Java code)

This blog post provides an introduction to the Apriori algorithm, a classic data mining algorithm for the problem of frequent itemset mining. Although Apriori was introduced in 1993, more than 20 years ago, Apriori remains one of the most important data mining algorithms, not because it is the fastest, but because it has … Continue reading

Posted in Big data, Data Mining, Pattern Mining, Programming | Tagged , , , , , , | 11 Comments

The SPMF data mining library: a brief history and what’s next?

In this blog post, I will talk about the well-known open-source library of data mining algorithms implemented in Java, which I am the founder of. I will give a brief overview of its history, discuss some lessons learned from the development of … Continue reading

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How to test if a data mining mining algorithm implementation is correct?

In this blog post, I will discuss how to check if a data mining algorithm implementation is correct and complete. This is a very important topic for researchers who are implementing data mining algorithms since an incorrect implementation may generate unexpected results. … Continue reading

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Drawing a set-enumeration tree using Java and GraphViz

In this blog post, I will explain and provide source code to automatically  draw the set-enumeration tree of a set using Java and GraphViz.  Drawing a set-enumeration tree is useful in computer science, for example in frequent itemset mining, a subfield of data … Continue reading

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Big Problems only found in Big Data?

Today, I will discuss the topic of Big Data, which is a very popular topic nowadays.  The popularity of big data can be seen for example in universities. Many universities are currently searching for professors who do research on “big data”. Moreover, … Continue reading

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Discovering and visualizing sequential patterns in web log data using SPMF and GraphViz

Today, I will show how to use the open-source SPMF data mining software to discover sequential patterns in web log data. Then, I will show to how visualize the frequent sequential patterns found using GraphViz. Step 1 :  getting the … Continue reading

Posted in Data Mining, Java, open-source, Programming, spmf | Tagged , , , , , | 8 Comments

Why data mining researchers should evaluate their algorithms against state-of-the-art algorithms?

sA common problem in research on data mining is that researchers proposing new data mining algorithms often do not compare the performance of their new algorithm with the current state-of-the art data mining algorithms. For example, let me illustrate this … Continue reading

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How to measure the memory usage of data mining algorithms in Java?

Today, I will discuss the topic of accurately evaluating the memory usage of data mining algorithms in Java. I will share several problems that I have discovered with memory measurements in Java for data miners and strategies to avoid these … Continue reading

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