PML: Matrix and Machine Learning Library Project

Using Python for scientific programming has many benefits. Especially IPython makes it very easy for your readers to reproduce your research findings. However, when time comes for running batch experiments, we usually find out that our Python/Matlab prototypes are not scalable. I was always thinking that we should as easily code in C++ as we… Read More »

Censored Gaussian Model

Recently I’ve started working with models including censored observations. In order to gain some insight to the problem, I’ve prepared a simple censored Gaussian model. Suppose we draw samples from a Gaussian distribution with unknown mean $\mu$ and precision $\tau$ $(= 1/\sigma^2)$ but can only observe the data points which are greater than a given… Read More »

Calculating The Inverse of Digamma Function

The digamma function is the logarithmic derivative of the gamma function which is defined for the nonnegative real numbers. When you are working with Beta and Dirichlet distributions, you seen them frequently. Furthermore, if you want to estimate the parameters of a Diricihlet distribution, you need to take the inverse of the digamma function. I… Read More »

Learning Mixture of Markov Models with EM

Here I present my Matlab implementation for learning Markov mixtures with EM algorithm. David Barber’s book explains the model and the EM derivation very nicely, and also provides a Matlab code package for it. Both the book and codes are open, you’re recommended to have look at them. However, Barber’s code is written for readability… Read More »

Bozcaada 2013 İstatistikleri

Cumartesi günü Bozcaada’da koştuk. Ben geçen seneki gibi yarı maraton koştum, kız arkadaşım da yine geçen seneki gibi 10K koştu. Bozcaada her zamanki gibi mükemmeldi, hava her zamanki gibi koşmak için fazla sıcaktı. Yokuşlar aynen eski yerlerinde bizi bekliyordu. 13. km’deki Ayazma yokuşuna yine ana avrat küfürler ettim ama bu sene yokuşlarda daha iyiydim. Yarışı… Read More »

Tarihin doğru zamanında doğmak

Geçenlerde iki  adet kitap aldım “Art, The Whole Story” ve “Ship, 5000 Years of Maritime Adventure“. Kitaplar insanlığın tarih boyunca farklı iki konudaki serüvenlerinin kısa özetleri. Sanat tarihin kitabı şu bölümlere ayrılmış: Tarih öncesinden 15.yy’a 15 ve 16. yy’lar 17 ve 18. yy’lar 19. yy 1900-1950 arası 1950-günümüz Denizcilik tarihi kitabının bölümleri tam olarak bu… Read More »

C++, give us the length of our arrays!

I’ve been the teaching assistant of the C++ course for a while, but I haven’t realized that C++ keeps the lengths of the dynamically allocated objects at the run time until this week. The array deletion operator delete[] which calls the destructor of each array element has to know the number of elements in the… Read More »