Monthly Archive: March 2013

How to convert S-JTSK coordinates to WSG84

Here in Slovakia and also in Czech republic our government uses special spatial geographic system called S-JTSK. This system uses x, y and z axis. However global standard is WSG84 (GPS position with latitude and longitude). Problem occurs while we want to convert this S-JTSK to WSG84. There are some programs which can do this but there are no good lightweight libraries which could be used and would be fast. So I analyzed one of these convertors in excel, extracted formulas and implemented it in Java. First thing we need to do is to convert S-JTSK x, y to S-JTSK…
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How to convert Czech map coordinates to WSG84

While crawling our beloved web we usually want to bind objects to GPS coordinates so we know where they are. Czech republic is not like any other country. In Czech republic there is search engine more popular than google no kidding. This search engine is called Seznam. Seznam provides services like search engine, catalogues, maps and many others. Seznam maps use special coordinate system which uses x and y axis. We usually want to convert these to GPS position. It is possible with their API but who would call their API when you can easily convert these coordinates with simple…
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One useful algorithm

There are many good algorithms solving many problems. But there is one algorithm which solves almost everything. I used this algorithm way before I knew that there are any algorithms. This algorithm is called Binary Search and many of you may know it. But did you know that with combination of regression it can solve almost any integer equation or problem ? Sometimes you don’t need to understand things to know the answers. You don’t need to solve equation if you can approximate solution and guess it on third try. Yes of course you need to at least think of the function…
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How to create SIP Stateful or stateless proxy for VoIP

Once upon a time we had a school project where we had to implement SIP stateful proxy. I took this serious and created rich document describing possible problems and solutions working with JainSIP for Java. Without further adduce I present you google doc containing questions and answers. Slovak Version I have also implemented SIP to XMPP gateway. If anyone is ever interested in this, feel free to contact me and I can provide you source code of my solution.

Music I listen to

Hello guys, I don’t like pushing people into something but the thing I am about to show you is pure awesomeness and I highly recommend to listen to at least one of these songs. I honestly have to say I like songs from all genres of music. But the thing I enjoy the most is Epic music. Yeah this genre is relatively new. It combines many genres and uses various tempo. But the core is very rich experience. You can feel the shivers and chills all over your body while listening to these. The other thing about it is that…
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