Is it possible to divide a raster into equal parts based off the sum of its cells?

[Anonymous User]

I'm working on a project to redraw district boundaries for our police department to help spread the work load more evenly among officers.

I created a raster layer showing overall time spent on calls across the city and was wondering if there is a way to divide the layer into equal value amounts rather than equal areas.

We have 4 districts and I'd like to divide my raster so that the amount of time (sum of the cells) is equally split.  The boundaries have been arbitrarily drawn throughout the years as new areas where annexed so completely redrawing the district lines is not a problem.

Any ideas on how to approach this or am I hoping for too much?

[Anonymous User]

Very cool!

[XanderBakker]

I changed the code to make the growth of each zone depend on the accumulated value. The zone with the lowest sum value gets to pick the next demand point (raster points). This made the result a bit better, but it is still not what I would accept (left before and right after the code change):

[Anonymous User]

Good morning Xander,

I've been a little side tracked with a couple of other projects and our GIS Day yesterday, which went very well by the way.  I'm finally able to get back on the redistricting.  I'm having some trouble with the Optimum Allocation failing on me.

I'm not sure if it's my parameters or if I'm not setting up my span tree correctly.

I'm using my raster grid points as the Input Origins having Supply and the GRID_CODE (Average Time) field as the Supply at Origin.

I'm using the Police Stations as my Input Destinations having Demand, and used the sum of GRID_CODE divided by 4 to find Demand at Destination.

I created a Span Tree and Network Dataset off of the raster grid points (21587 in total), it's only giving me the option of Length as the Impedance Attribute but I think it should be a time value if I'm thinking about this right.

As always, any thoughts or ideas you have are greatly appreciated.