[UW-GIS-L] Raster masters needed!

[Phil Hurvitz]

You may need to use a larger cell size, or perform a reclass to get fewer 
values for getting a VAT.  The straight-line distance tool should return 
values to the full extent; maybe the geoprocessing settings are 
overriding?  Or is the output limited to the extent of the input feature 
extent?

-P.

  **************************************************************
  Phil Hurvitz, MFR | PhD Candidate, Urban Planning | Gould 317
     College of Architecture and Urban Planning | Box 355726
  University of Washington, Seattle, Washington  98195-5726, USA
  phurvitz at u.washington.edu | http://gis.washington.edu/phurvitz
  "What is essential is invisible to the eye." -de Saint-Exupéry
  **************************************************************

On Tue, 17 Apr 2007, Regan Smith wrote:

> I tried Euclidean Distance, but the problem there was that I need an
> attribute table, and the output raster for this tool is a 32-bit floating
> point raster for which a VAT cannot be built.  I tried to convert it to
> integer, but was returned the error "too many unique values".
>
>
>
> Using the straight-line tool on the spatial analyst toolbar also has its
> problems.  While I can ultimately convert the output raster to integer and
> get a VAT, the problem occurs with the extent.  The straight-line tool
> doesn't return values for the full extent of my planning area, only for the
> extent of the analysis (and I do have the extent set to the planning area in
> the spatial analyst toolbar).  So, either way neither of these seem to work.
>
>
>
> Also, I don't think the Cost Distance function is what I need because that
> searches for a least cost route.  I'm just trying to create a buffer.
>
>
>
>  _____
>
> From: uw-gis-l-bounces at mailman1.u.washington.edu
> [mailto:uw-gis-l-bounces at mailman1.u.washington.edu] On Behalf Of Luke Rogers
> Sent: Tuesday, April 17, 2007 9:36 AM
> To: 'UW - GIS Discussion & Support'
> Subject: RE: [UW-GIS-L] Raster masters needed!
>
>
>
> I think you have two options: Cost Distance or Euclidean Distance. Euclidean
> Distance should be fairly easy to run. You can input features like points as
> your source or use a raster with non-NoData cells. The only other bit of
> info that EucDist needs is the output. Rather than using the Raster
> Calculator use the tool: ArcToolbox > Spatial Analyst Tools > Distance >
> Euclidean Distance. This will give you a grid of the distance to the
> features. You can then multiply that distance grid by whatever scale factor
> to get the weights you desire.
>
>
>
> The Cost Distance function is a bit more complex but will do more if the
> Euclidean Distance function doesn't get you exactly what you need.
>
>
>
> -Luke
>
>
>
>  _____
>
> From: uw-gis-l-bounces at mailman1.u.washington.edu
> [mailto:uw-gis-l-bounces at mailman1.u.washington.edu] On Behalf Of Regan Smith
> Sent: Tuesday, April 17, 2007 9:19 AM
> To: uw-gis-l at u.washington.edu
> Subject: [UW-GIS-L] Raster masters needed!
>
>
>
> To all you raster masters out there:
>
>
>
> I am in dire need of some assistance figuring out what should basically be a
> pretty simple task.  Essentially, I am simply trying to weight a raster, and
> assign proportionately decreasing weights to cells moving away from the
> feature in the raster.  However, I have run into a slew of issues, including
> problems with extent, floating bit rasters w/ no attribute tables, etc.  I
> am convinced that all I need to do is to figure out a raster calculator
> command that works, but so far I haven't been smart enough to figure it out.
> Numerous hours (honestly, like the last 10 days straight) have been spent
> reading EVERY help page on ESRI, to no avail.  I visited the GIS lab today,
> and was told my last bet was this list.  Is anybody out there willing to sit
> down with me and help me figure out how to implement this task?  I will make
> you feel very smart, very appreciated, and will pay you in kind, through
> beers, coffee or cookies - whatever you like.
>
>
>
> I anxiously await your response!
>
> Cheers,
>
> Regan
>
>
>
> Regan Smith
>
> M.S. Candidate
>
> Ecosystem Ecology and Conservation Lab
>
> College of Forest Resources
>
> University of Washington
>
> (c) 206.349.1032
>
> (o) 206.616.9661
>
>
>
>