Comparison of misc optimization methods available in R

Introduction

In this article I would like to describe the results of my comparison of several popular optimization algorithms available in R. First of all, it would be useful for educational purposes (become familiar with usage of optimization methods in R, etc.). At second, it allows to understand "power" of optimization methods, their strengths, and weaknesses.

 

Disclaimer. The article does not cover all optimization methods available for R. Also it does not claim that one algorithm is better than other. It just presents results of my personal investigation.

 

Hierarchical clustering by using T-SQL

Introduction

 

 

In this blog post, I would like to show how to implement hierarchical data clustering by using T-SQL.

 

Hierarchical clustering is probably the simplest method of cluster analysis. The are two basic types of this method - divisive (processing begins from the single cluster and on each step clusters are divided) and agglomerative (on the beginning each item resides in its own cluster, on the next steps we merge two closest clusters until all clusters are merged into single one).

 

The script below utilizes agglomerative approach.

Parse and show bitmap images by using T-SQL

Introduction

Inspired by this Itzik Ben Gan’s post, I wrote T-SQL query which parses a bitmap image, converts it to SQL Server Geometry format, and shows results in Spatial Data viewer.

 

The query is designed for SQL Server 2008 and supports processing of monochrome uncompressed bitmap images.