The CWU Tools software is an ongoing project at Central Washington University to build additional ArcGIS functionality. At present, this tool includes two separate functions:

1) The point grid generator will generate either a regularly spaced or random grid of points within a user-specified area. The output is a point shapefile. Area of extent can be generated in one of two ways - either the user types in the NSEW extents or draws a rectangle (using the 'draw a rectangle' drawing tool) on top of an existing coverage and presses the update area button. If the regular grid of points is required, the user then enters the distance between points (in map units). If random points is required, enter the number of points you desire. NOTE: an oddity of the software is that you must put in a point spacing even if you want random points. Doing this does not affect output, but if you don't go through the spacing thing first, hitting the OK button does not become an option.

2) The add statistics to polygon shapefile based on raster clip tool allows a polygon file to operate in a similar manner to gridspot. It will extract the number of pixels of each class beneath a polygon and add that number to a column in the polygon file. There is currently a limit of 42 classes in your raster file.To explain with an example: You have two maps - one is a landuse map with 15 different classes (as a raster) and a polygon file which is the result of a 500m buffer around, say, hospitals. The question becomes, what are the landuse characteristics within 500m of hospitals. This software will then add 15 columns (one for each landuse class)to the polygon attribute file - then, for each individual polygon, the number of pixels of each class underneath each polygon is added to the attribute file.


The CWU tools dll and a readme (how to install) file can be downloaded HERE .


If you want the old gridmaker software, which is a standalone executable which generates a regular grid of points and outputs a text file can still be found HERE.


The software is free, please acknowledge the author.

Bob's Homepage # Geography Dept. # CWU

last modified: 4 April, 2010