Tag Archives: map algebra

MFworks Tutorial – 01 MFworks

Revised on: 2015-10-02

These pages will explain how to do network analysis in raster GIS using MFworks as an example software. MFworks has evolved from MAPFactory, originally designed by C. Dana Tomlin, the father of map algebra. This is unmistakably seen in MFworks command procedures and scripting language. MFworks is thus the ideal companion for teaching and learning Tomlin’s principles of map algebra. MFWorks was featured in a very positive review in the June 2000 edition of GeoEurope as the only raster GIS truly capable of network analysis. I decided to put that statment to the test.

MFworks

Conducting network analysis in MFworks comprises iterative steps that lead to a functioning network. These steps will convert map layers with square cells into linear elements that are linked together as lines, with directional flows assigned to each cell, and map layers containing cost variables. This example, based on my MSc in GIS, will show how network analysis is performed in MFworks, both with a fixed travel cost for the entire time of travel and with a dynamic travel cost, where the cost of travel changes during the time of travel.

MFworks – step by step

MFworks Tutorial

How to make a straight line square

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Revised on: 2011-07-22

Euler’s famous “Königsberg bridge” question, dating back as far as 1736, is often seen as the starting point of modern path finding – was it possible to find a path through the city of Königsberg crossing each of its seven bridges once and only once and then returning to the origin? Euler’s methods formed the basis of what is known as graph theory, and which in turn paved the way for path finding algorithms. Traditionally, network analysis, path finding and route planning have been the domain of graph theory and vector GIS, which is where most algorithms find their application. Contrary to such common wisdom, the research of this thesis for the Msc in GIS explores the topic of network analysis in raster GIS, using MFworks as example software. Current algorithms, procedures and network modelling techniques are investigated and common artefacts are explained.

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Book Review: This is where raster GIS started…

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Revised on: 2011-03-08

…well not really, but Geographic Information Systems and Cartographic Modeling by Dana Tomlin sparked the scientific interest in it. The original concepts surrounding surface analysis date back to late 1970s and were championed by Dana Tomlin with his PhD dissertation in 1983, which was later published as this book. In the book, Tomlin introduces map algebra operators based on how a computer algorithm obtains data values for processing raster surfaces. He identifies three fundamental classes: local, focal and zonal functions. Tomlin is a must to any academic student of GIS, since much or nearly all work on raster GIS springs off from Tomlin’s work. The illustrations clearly show that this is an old book, but the knowlegde still remains as brilliant today as it was then. This is a book you want to own, simply because it is very sought after and constantly unavailable from your university library.