All posts by Markus

Background

Before i start documenting my path to being a trader, i should tell a bit about my background. So here it comes:

I studied math and quickly got interessted in the markets (mainly futures and FOREX) cause i loved the idea of getting rich quick just from coding some algos at home. So i started to code trading systems and learned a lot about the markets. And didn’t earn anything from it, of course. Once i even coded my own exchange with clearing algo and everything. Trading a completly theoretical asset was super fascinating. Basically like we do it with crypto currencies now, just without getting any money out of it…

Continue reading Background

Bitcoin is not a currency

I often hear people claiming that Bitcoin will replace our current currencies. And with the rise in value these voices grow louder. But unfortunately it seems they don’t understand the basics of the financial system.

Don’t get me wrong: blockchain is an interesting concept with lots of useful applications. It may even revolutionize different fields in our society. But Bitcoin will never be a mainstream currency. The average person will never buy its daily coffee with Bitcoin. And here is why: Continue reading Bitcoin is not a currency

having 100% code coverage doesn’t solve all your problems, having less solves even less.

I recently came across a post about achieving 100% code coverage and how reassuring it is. But is it? 

What does 100% code coverage mean? Ignoring the different definition it basically says that all your code was executed ( covered ) during the tests. (the definition of “all your code” is a bit flexible here) But does that say anything about your code quality or about the quality of your tests? 

The answer is no. And it’s a big NO because having a full coverage doesn’t mean your code does what it should. Remove all the assertions from your tests and you still have 100% coverage, but with no quality assurance whatsoever. The only real advantage of 100% coverage is that you know there is no unexpected exception thrown (unless you did something real nasty like @expected(exception) in your tests, but then you had it coming). At least not when executed the way you did.  (yes 100% coverage doesn’t mean you covered all possible cases, just all code). 

On the other hand, having less than 100% means you missed some code and therefore definitly don’t know how it behaves in production. 

Long story short: 100% code coverage is a good thing to have, but it’s like being able to type fast: good to have but when it comes to quality coding you need much more than that. 

Fitting Plane to Point Cloud – Hands on

In my last post i described how to get the equations for fitting a plane to a given pointcloud. Now lets put them into some sample code. I will use the same notation as in the previous post.

When i first started with the optimization, i thought about distinguishing the different cases by Txx != 0. I already worked out the math for the case Txx == 0 etc. And then i started testing with real world data. Random points which are approximatly on a plane. The sad part is: Even with a pointcloud where Txx should be approximatly zero it wasnt close enough to make a valid decision. (And yes i know that comparing a float with 0 is not the way you do it) So sometimes the algorithm ended in the Txx != 0 case, setting c = 1 where c should actually be 0, but because of the unequally distributed values, it wasnt… Continue reading Fitting Plane to Point Cloud – Hands on

3D linear regression: Fitting planes on Pointclouds

Time for a math-post.

Linear regression, or fitting a line on a list of 2D points, is quite common with lots of code samples. But once you want to go further torwards more dimensions, there are no examples whatsoever… You find the wikipedia article about the theory, but eveything is in general terms. Its about calculating the invers of a matrix and lots of stuff that you dont want to do when thinking about performance. Continue reading 3D linear regression: Fitting planes on Pointclouds

ICP with SVD – Hands on

Hi everyone,

since you came across a post with a cryptic title like that, chances are high that you are already deep in the topic. But for the 1% who dont, here is a short background info:

3D-Scan Matching using Iterative Closest Points (ICP)

When you have a 3D-Scanner (like a Laserscanner, Kinect or whatever) and try to scan a room/object the first problem is how to combine to scan-frames to one pointcloud. Usually  the scanner moved between the frames still providing some overlapping to be matched. But how to do that? Continue reading ICP with SVD РHands on

Integrating Unity into a Native iOS App – Example

After describing the Idea of adding Unity into a native App here, i got a lot of questions about some sample source code. So here it is ūüėČ

For a minimum working sample of how to integrate Unity, you need a Unity project of course. Best way to start is from the iOS Export of the unity project. Personally i prefer to not change any of the Unity-generated files itself, but only integrate them, so i dont have to care about these changes everytime i do a new unity export.

After exporting from Unity you get a “normal” XCode project containing a “Classes” and a “Libraries” folder. You should be able to run it on a device, otherwise there is some problem with your Unity-project which need to be fixed before integrating it. Continue reading Integrating Unity into a Native iOS App – Example

Unity 5 with il2cpp into iOS

Integrating Unity as a Subview into a native iOS-App went from being a pain in the ass to being kinda smooth while Unity evolved from 3 to 4. But when you needed to pass data(and i mean more than serialized stuff via sendMessage) into the view the whole Mono-stuff was still… lets say inconvenient. But fear not, Unity 5 is here for the rescue!

Stepping from 4 to 5, Unity decided to drop Mono and use il2cpp instead.¬†Since we went through a lot with mono and it was always in a state of “i hope this isnt blowing off” we surely took a look into the new and fancy stuff. Continue reading Unity 5 with il2cpp into iOS