Links: Java and XML Tutorials

(Tuts for myself). Here are some article links about XML and how to parse it in Java using XPath. They might be useful.

Understanding the Bias-Variance Trade off

When we discuss prediction models, prediction errors can be decomposed into two main subcomponents we care about: error due to “bias” and error due to “variance”. There is a tradeoff between a model’s ability to minimize bias and variance. Understanding these two types of error can help us diagnose model results and avoid the mistake of over- or under-fitting.

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From Java to Java.Next – Quick Review of Scala

To start this quick review about Scala as Java.Next, let us see an interesting perceptive observation from Martin Fowler about Java and its legacy as follows.

“The legacy of Java will be the platform, not the language”

This statement is interested since more than 200 languages run on Java Virtual Machine (JVM) nowadays [1]. This condition emerges since Oracle hosted the annual JVM Language Summit in 2008, which has given implementers of alternative languages on the JVM an opportunity to collaborate openly with Java platform engineers. For example, let us consider Clojure, Groovy, Scala, and the new one, Kotlin. Each language brings interesting new capabilities beyond of Java language itself. In general, two initial significant advantages that these languages tend to provide are reducing the amount of verbosity in code. Hence it allows us to focus on the essence of problem solving. The second advantage is enabling some degree of functional programming styles [2]. This short review will be limited to Scala as an alternative programming language of Java.

As introduced in their official website [3], Scala is an elegant and concise programming language that integrates both functional and object-oriented paradigms smoothly. This enabling programmers to be more productive while retaining full interoperability with Java and taking advantage of modern multicore hardware. It is statically typed and well found with an expressive type system, which supports: generic classes, variance annotations, upper and lower type bounds, inner classes and abstract types as object members, compound types, explicitly typed self references, views, and polymorphic methods.
Continue reading “From Java to Java.Next – Quick Review of Scala”

Reblog: The International TOEFL and IELTS Test Centres in Jakarta

Bagi Anda yang ingin mengikuti tes international TOELF atau IELTS berikut ini adalah alamat official test centres TOEFL dan IELTS di Jakarta, semoga bermanfaat :).


Indonesian International Education Foundation (IIEF)
Menara Imperium, 28th Floor, Suite B
Metropolitan Kuningan Superblok, Kav. 1
Jl. H. R. Rasuna Said
Jakarta 12980
Tel: +62-21-831-7330
Website :
Toefl test information :

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Plaza Kuningan
Menara Selatan, 3rd floor
Jl. H.R Rasuna Said Kav C11-14
Jakarta 12940
Telp: 021-5213350
Fax : 021-5213349
Website :

Komp Ruko Plaza 5
Pondok Indah Blok D 11
Jl. Margaguna Raya
Jakarta Selatan 12140
Tel:   +62 21   7234 944 / 727 90950
Fax: +62 21   7234 933
Website :

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