Difference between revisions of "Main Page/Research/Smart Maps/dwelling units"
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Phil Hurvitz (talk | contribs) |
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## decide on a cell size in advance | ## decide on a cell size in advance | ||
### if the cell size is 10 m, then the area of the cell is 100 m<sup>2</sup> = 1076 ft<sup>2</sup> | ### if the cell size is 10 m, then the area of the cell is 100 m<sup>2</sup> = 1076 ft<sup>2</sup> | ||
| − | ## prepare parcel data with number of dwelling units per parcel | + | ## prepare parcel data with number of dwelling units per parcel |
| − | ## add a field for du_per_ | + | ### add a field for du_per_'''X'''_cell (e.g., <tt>du_per_10m_cell</tt>; I used precision 18 scale 10) |
### calculate as dwelling_units * conversion / shape_area | ### calculate as dwelling_units * conversion / shape_area | ||
###: e.g., for 10 m<sup>2</sup> cells, the conversion will be 1076 | ###: e.g., for 10 m<sup>2</sup> cells, the conversion will be 1076 | ||
| − | ###: to give the number of dwelling units per cell | + | ###: to give the number of dwelling units per cell |
# In ArcGIS (for spatial operation) | # In ArcGIS (for spatial operation) | ||
## convert to raster at 10 m spacing (32.808 ft), call it <tt>[du_per_cell]</tt> | ## convert to raster at 10 m spacing (32.808 ft), call it <tt>[du_per_cell]</tt> | ||
Revision as of 15:30, 6 May 2010
Create a smart map raster that represents the count or density of dwelling units
- In Access (for faster processing)
- decide on a cell size in advance
- if the cell size is 10 m, then the area of the cell is 100 m2 = 1076 ft2
- prepare parcel data with number of dwelling units per parcel
- add a field for du_per_X_cell (e.g., du_per_10m_cell; I used precision 18 scale 10)
- calculate as dwelling_units * conversion / shape_area
- e.g., for 10 m2 cells, the conversion will be 1076
- to give the number of dwelling units per cell
- decide on a cell size in advance
- In ArcGIS (for spatial operation)
- convert to raster at 10 m spacing (32.808 ft), call it [du_per_cell]
- convert the raster to points
- now there is a data set of points where each point has the value of the number of dwelling units per cell/point
- simple density moving window analysis with 833 m (2734 ft) radius and population field = grid_code, units square meters (call this grid simple_dens)
- multiply simple_dens by the radius area to obtain focal count (following this analysis, [simple_dens] * sqr (833) * pi
