Difference between revisions of "Main Page/Research/Smart Maps/dwelling units"
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Create a smart map raster that represents the count or density of dwelling units | Create a smart map raster that represents the count or density of dwelling units | ||
| − | # decide on a cell size in advance | + | # In Access (for faster processing) |
| − | ## if the cell size is 10 m, then the area of the cell is 100 m<sup>2</sup> = 1076 ft<sup>2</sup> | + | ## decide on a cell size in advance |
| − | # prepare parcel data with number of dwelling units per parcel (I used precision 18 scale 10) | + | ### if the cell size is 10 m, then the area of the cell is 100 m<sup>2</sup> = 1076 ft<sup>2</sup> |
| − | # add a field for du_per_[cell] (e.g., du_per_10m_cell) | + | ## prepare parcel data with number of dwelling units per parcel (I used precision 18 scale 10) |
| − | ## calculate as dwelling_units * conversion / shape_area | + | ## add a field for du_per_[cell] (e.g., du_per_10m_cell) |
| − | ##: e.g., for 10 m<sup>2</sup> cells, the conversion will be 1076 | + | ### calculate as dwelling_units * conversion / shape_area |
| − | ##: to give the number of dwelling units per cell<sup>2</sup> | + | ###: e.g., for 10 m<sup>2</sup> cells, the conversion will be 1076 |
| − | # convert to raster at 10 m spacing (32.808 ft), call it <tt>[du_per_cell]</tt> | + | ###: to give the number of dwelling units per cell<sup>2</sup> |
| − | # convert the raster to points | + | # In ArcGIS (for spatial operation) |
| − | #: now there is a data set of points where each point has the value of the number of dwelling units per cell/point | + | ## convert to raster at 10 m spacing (32.808 ft), call it <tt>[du_per_cell]</tt> |
| − | # simple density moving window analysis with 833 m (2734 ft) radius and population field = grid_code, units square meters (call this grid '''simple_dens''') | + | ## convert the raster to points |
| − | # multiply '''simple_dens''' by the radius area to obtain focal count (following this analysis, <tt>[simple_dens] * sqr (833) * pi</tt> | + | ##: 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, <tt>[simple_dens] * sqr (833) * pi</tt> | ||
Revision as of 15:27, 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 (I used precision 18 scale 10)
- add a field for du_per_[cell] (e.g., du_per_10m_cell)
- 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 cell2
- calculate as dwelling_units * conversion / shape_area
- 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
