Category Archives: redistricting algorithms

Howfar It Is from Here to There

My redistricting algorithm selects census blocks based on their distance from the district center. The coordinates of the district center and of the next census block are given in latitude and longitude integer tenmillionths degrees. Of the many methods to calculate that distance, which is best? A first method assumes the earth is flat, and […]

The Input files

For the computer to do redistricting, the computer must receive certain data. Sandboxwalls used three data files as input. The first file contained the census block data. The second file contained the borders of the State as a polygon. The third file contained the information on what census blocks were immediately adjacent to any given […]

Summer is not enough to redistrict

      Summer went by really fast. I was busy enough with other problems. Since my blog doesn’t really have an audience, it is more like a diary to be reread someday.   A relative of mine peeked at it.          I downloaded census and other data for Arizona. I compiled code I wrote in Fortran.  Sorting […]

Sorting the census blocks for redistricting

  Another method for sorting the census data for redistricting has occurred to me. Back in ancient times, there were machines that could sort punch cards. See: http://en.wikipedia.org/wiki/IBM_80_series_Card_Sorters.  For example, cards could be sorted into ranges of latitude. The cards would be conveyed horizontally until they dropped into the proper bin below.  Today, the same […]

Closs Enuf 4 Govment Work

  For redistricting, random processes should not be used.  Certain software given the identical census data run on a compatible computer should yield identical results.  That way all parties can verify that the results are not just something cooked up in a smoke filled room.  If the results from different computers aren’t precisely identical, careful analysis […]

Out of Sorts with Redistricting

      My ideas for redistricting with a sandboxwalls program involve a lot of data sorting.  First, the census blocks of a state are sorted by latitude.  However, the states are two dimensional, not one-dimensional.  Consider a television picture.  The picture is made up of horizontal stripes.  Using that concept, the latitude of the State is […]

Faster than a speeding square root

In the data from the Census Bureau, the location of the census blocks are given by latitude and longitude. Instead of degrees, minutes, and seconds, the latitude and longitude are given in millionths of a degree. Fortunately, these are conveniently expressed as 32-bit integers. Finding the geographical distance between two points usually means employing the […]

Make my districts contiguous please

In redistricting, contiguous is a fancy word meaning the district is one lump without any loose flakes floating around. If a district includes part of a county, I see  no reason for that district to have little pieces of that county that are unconnected with the main part of the district. This assumes that the county […]