[UW-GIS-L] Raster masters needed!

[Regan Smith]

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

 

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