Team J Saket Deepak

Team “J”

Saket Deepak

Permap

The fundamental purpose of Permap is to uncover hidden structure that might be residing in a complex data set.  Compared to other data mining and data analysis techniques MDS is growing increasingly popular because its mathematical basis is easier to understand and its results are easier to interpret (Fitzgerald & Hubert, 1987).Permap is an interactive computer program.  It offers both metric (ratio and interval) and non metric (ordinal, ratio + bounds, interval + bounds) MDS techniques.  It solves problems in up to eight dimensional spaces and allows boundary conditions to be imposed on the solution.  In the technical jargon, Permap treats "weighted, incomplete, one-mode, two-way" or "weighted, incomplete, two-mode, two-way" data sets.  Other jargon would say it handles weighted, symmetric, incomplete, triangular or rectangular data sets.  The word “weighted” means each data point can have its own multiplier that reflects in some way the importance or reliability of the point.  The word “symmetric” means that Permap assumes that the (i, j) proximity value equals the (j, i) proximity value, and “incomplete” means that it can handle missing data.  The one-mode, two-way and square references indicate that Permap can analyze a matrix of proximity information between several objects, and the two-mode, two-way and rectangular references means it can analyze objects each of which are specified by an array of attributes. Permap can treat up to 1000 objects at a time and each object can have up to 100 attributes.  It is easy to use, Windows PC-based, visually oriented, and allows real-time interaction with the analysis.  It has been designed to have an intuitive interface and it avoids many of the arcane alternatives that are seen in the research literature but are never used in practice. 

System Requirements

Permap will run on any contemporary personal computer using a Windows operating system.  It is not particularly demanding in terms of computer speed, but if the problem is large, say more than 100 objects, then at least a 1-GHz computer is recommended.  Problem solution time is often controlled as much by the computer's available RAM (random access memory) as it is by the computer's processor speed.  With the XP or 2000 Windows operating systems you should have at least 512 MB and preferably 1 GB of RAM. Vista needs 1 GB or more of RAM.

Installation

Obtain a copy of the file Permap.zip.  This file is available on the Internet at www.ucs.ull.edu/~rbh8900/permap.html.  After downloading the Permap.zip file, open it using any of numerous decompression utilities.  Usually you will have a zip/unzip program included as part of Microsoft suite of programs.  If not, one such utility is Zip Genius available at http://www.zipgenius.it/index_eng.htm.  Zip Genius is a free program that is particularly user friendly, downloads fast, installs easily, and can be run with no training.  After unzipping Permap, you will have Permap.exe, some Windows library files (ocx and dll extensions), some example files, a default-values file, and a WAV file.  You might want to put a shortcut to Permap.exe on your desktop.  Right click on Permap.exe (in whatever directory you chose to put the unzipped files) and drag it to the desktop.  Choose "Create Shortcut Here" when you release the right mouse button.  Permap is now ready to use.  Permap can be uninstalled simply by erasing the directory you used to hold the Permap files because no Registry entries have been. Start the program by double clicking the Permap shortcut, by double clicking on Permap.exe in the directory where you put Permap, or by entering its location and name in the Run input box's "command line" which is accessed via the Start button. Permap can be controlled by a mouse or keyboard.  The alt-key gets you to and from the menu bar, the tab-key shifts between controls, and the enter-key activates a control. 

Data Input

Data are entered from a text file (i.e., a file stored in ASCII or ANSI format).  Any modern word processor can save information in these generic formats.  For instance, if you use WordPerfect, use File/Save As and choose ASCII DOS Text or ANSI Windows Text from the File Type box at the bottom of the screen.  If you use MS Word, use File/Save As and choose Text Only or MS-DOS Text from the Save as Type box at the bottom of the screen.  Alternatively, it is often faster and easier to use Notepad, the simple text editor that comes with all Windows operating systems.  Notepad is designed for quick entry of short segments of unformatted text.

Permap's data files are based on freeform data entry.  This means that keyword identifiers announce the presence of various data elements and that these data types can be present in the file in any order.  Comment lines can be placed freely throughout the data file as long as they are not placed between a keyword and its following data.  All optional information is covered by default values.  This means that if you choose not to use weights then they need not be mentioned in the data file. Here is a very simple data set that assumes your data are in the form of dissimilarities.  All the sentences to the right are for explanation purposes and are not part of the actual data file. 

Example of data input

NOBJECTS=6 Gives the number of objects in the analysis.

NATTRIBUTES=3 Gives the number of attribute values for each object.

ATTRIBUTELIST   Announces that attribute values follow.

1, 1, 2             any range can be used for the data.

1, 2, 2          the data can be separated with space(s), a comma,

3, 3, 2 or both.  ATTRIBUTELIST is all one word and

3, 4, 0 capitalization is optional.  All data entries must be numbers.

3, NA, 0 Missing entries are shown by "NA" or "na."

1, 6, NA It is acceptable to name the objects.