Data Collection:

All U.S. Census track data and shape files used in this GIS project were downloaded from a Chicago city based website: http://www.maps.cityofchicago.org.

In general, this particular website is exceptionally well designed in terms of providing users with a wide selection of various categories of city based maps that are stored in viewable PDF formatt. Such map categories include Land-use Maps, Census Maps, Transit Maps, and various others. Conviently, most of the map components that were found in PDF formatt, could also be found in the corresponding downloadable shape files and census data that are stored as compressed Winzip files. Map components or shape files that were downloaded from this project served mainly for two purposes, specifically as factors and contraints. In general, factors for this particular project could be defined as criterias that would influence the decision making and planning process involved when establishing a fine dining Chinese restaurant. While constraints represent areas where establishment of a restaurant is not physically possible as such areas include, forests, parks, waters bodies, and school grounds.

As mentioned earlier in the introduction, the factors for this particular project include, ethnicity (Chinese), Spoken language, Annual Family Income, Family size, Number of Vehicles owned, and Possession of a Real estate unit such as a house. In general, all the data regarding to these chosen factors were stored in four seperate Census Track compressed data files.. When decompressed, each data file reveals several rows and columns of averaged numerical values, specfically each column represents a specific attribute (i.e. ethincity, race, age etc.) while the each row corressponds to a particular census track area (876 in total) found in the city of Chicago. Prior to setting up the shape files that correspond to the factors chosen for the project, it was neccessary to 'join' the Census data with the corresponding Census Track map using ArcMap software. Once the vector image files were created for all the required factors, they were then converted to raster images using ArcMap specifically using "Feature to Raster" tool found in the Arctool box. During the rasterization process, it was important to keep the 'output cell size' for all images the same as this was crucial during overlaying process that would occur later on. Since all the rasterized images were required to be sent to another GIS software Idrisi for Spatial analysis, all rasterized image were linked to their corresponding ASCII raster files.

Before the ASCII raster files can be fully utilized in Idrisi, all the output files were converted from real number formatt to integer as this allow basic setup for boolean operations such as reclass and and assign operations. In addtion, all ASCII raster files or images were given a pre-determined reference coordinate that was specified in the metadata. For this particular project, all images were referenced to 'spc83il1 which is an acroynm for Illinois State Plane Coordinate System Eastern Zone. Once all the ASCII raster files were have the same projection and resolution (cell size), the last preparation steps required involved making column and row values or position consistent for all images. This was acomplished by finding the raster image that have both the smallest column and row value. Once this particular raster image was found, the column and row values for all the other images were reformatted to match the smallest representative's values. This was accomplished through the use of Idrisi's' image windowing option.

The preparation steps made for the 'constraint' images is very similar to that of 'Factor' categories, although the initial steps involved joining shape files with corresponding data base were not required.

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