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Hierarchical Linear Model 23 Jul 2013 | 12:39 am
Linear regression probably is the most familiar technique of data analysis, but its application is often hamstrung by model assumptions. For instance, if the data has a hierarchical structure, quite o...
Bayesian Classification with Gaussian Process 7 Jan 2013 | 12:14 am
Despite prowess of the Support Vector Machine, it is not specifically designed to extract features relevant to the prediction. For example, in network intrusion detection, we would like to learn relev...
Bayesian Inference Using OpenBUGS 23 Jul 2012 | 09:31 am
In our previous statistics tutorials, we have treated population parameters as fixed values, and provided point estimates and confidence intervals for them. An alternative approach is the Bayesian sta...
Significance Test for Kendall's Tau-b 16 Apr 2012 | 10:02 am
A variation of the standard definition of Kendall correlation coefficient is necessary in order to deal with data samples with tied ranks. It known as the Kendall’s tau-b coefficient and is more effec...
Support Vector Machine with GPU, Part II 22 Oct 2011 | 03:29 pm
In our last tutorial on SVM training with GPU, we mentioned a necessary step to pre-scale the data with rpusvm-scale, and to reverse scaling the prediction outcome. This cumbersome procedure is now si...
Support Vector Machine with GPU 28 Aug 2011 | 06:51 pm
Most elementary statistical inference algorithms assume that the data can be modeled by linear parameters with a normally distributed error component. A new class of algorithms called support vector m...
Kendall Rank Coefficient 8 Dec 2010 | 08:00 am
The correlation coefficient is a measurement of correlation between two random variables. While its computation is straightforward, it is not readily applicable to non-parametric statistics. read mor...
Hierarchical Cluster Analysis 26 Nov 2010 | 07:44 am
With the distance matrix found in previous tutorial, we can use various techniques of cluster analysis for relationship discovery. For example, in the data set mtcars, we can run the distance matrix w...
Type II Error 23 Nov 2009 | 06:12 pm
In hypothesis testing, a type II error is due to a failure of rejecting an invalid null hypothesis. The probability of avoiding a type II error is called the power of the hypothesis test, and is denot...
Multiple Linear Regression 15 Sep 2009 | 08:30 am
A multiple linear regression (MLR) model that describes a dependent variable y by independent variables x1, x2, ..., xp (p > 1) is expressed by the equation as follows, where the numbers α and βk (k =...
