14 replies to this topic

[araki5]

"

I 
had previously been looking for another ArcView 3.1 function which was 
not included in ArcGIS, I can't remember what it was, but I downloaded 
XTools Pro. You want to use the Layer Features -> Erase Features 
tool.

http://www.xtoolspro.com/

It was free as far as I remember, although it looks like you can pay on the site also...

Here 
is the file if you don't want to go through the hassle. BTW I noticed 
one area where it did not subtract certain features. Maybe your polygon 
is not closed in the boundaries layer... you should notice it right 
away.

http://

Ben,

Many thx for the shape file, it looks like it worked for you.

I
use XTOOLSPRO (freeware version) and it has ALWAYS done me right.
However, I am trying to use the erase function, and it seems like it
ERASES, the areas OUTSIDE the project boundary’s. I need those areas.

How did you get yours to just give u the areas outside?

Thx,
"

[araki5]

"

I got this to work by doing the following:

1) 
Export a .shp copy of your ""PlanningVersionProject"" file into the same 
directory as your Wetlands shape file. When I initially opened your 
file and attempted to edit the polygons, the Start Editing dialog box 
was showing two different drive locations (the PVP file was showing 
that it is in a Geodatabase?). As far as I know, if you want to use the 
clip function listed in the editor menu, you need to edit from the same 
location. Thus the export.

2) I named the new .shp file ""PVP_New""

3) 
Start editing - select ""PVP_New"" as your target layer, and once again, 
make sure your Wetlands file and the PVP_New file are both editable.

4) Select any ""PVP_New"" polygon with the Edit Select tool that has a Wetlands polygon both inside and outside of it.

5) 
Under the Edit tool drop down menu (don't go to Toolbox) select ""Clip"" 
and choose the default of ""discard the area the intersects"" and hit OK.

6) 
Turn off the ""PVP_New"" layer. You should only see the area of the 
Wetlands polygon that was outside of the project area. You may also 
want to ""Explode"" or ungroup the geometry after this step is complete 
as to isolate the individual polygons so you can calculate the area of 
each one.

Give this a try and let me know if it worked for you.

http://

Erin,

Thx
for the tip, however when I was editing, I went to the editor toolbar
and tried to click the CLIP command, but it’s greyed out. I think you
need ARCInfo for this function, I only have ARCView Desktop 9.1,

I had both shapefiles selectable and still didn’t work out. I made sure the editable layer was PVP_New, still nothing.

Thx for the help.

http://

Erin,
My mistake, YOU HAVE TO SELECT something in order to clip.
Sorry. "

[benbakelaar]

"

Ben,

Many thx for the shape file, it looks like it worked for you.

I 
use XTOOLSPRO (freeware version) and it has ALWAYS done me right. 
However, I am trying to use the erase function, and it seems like it 
ERASES, the areas OUTSIDE the project boundary’s. I need those areas.

How did you get yours to just give u the areas outside?

Thx,

http://

Hm...
Maybe you did it in reverse? I erased the project boundaries FROM the
wetlands. Let's see.... For ""input feature layer"" I chose
""WetlandMergeDelineate..."" and for overlay layer I chose
""PlanningVersionProject"". That's what got me the outside areas. The two
checkboxes were checked by default under Output storage. "

[araki5]

"Ben,
Thx
for the tip. It looks like when I originally tried to use ERASE, I
mixed up the order for the clip operation. So what I ended up doing was
from XTOOLS PRO toolbar --> Layer Operations --> Erase features.
At this point I need to use the Project boundary's shape to clip.

1.First layer is the Wetlands
2.Name my resultant shape
3.Overlay with the Project Boundary's.

The result is the leftovers outside.

thx
a lot Ben. I thought I might have done this in the Geoprocessing
portion of my Intermediate class last year, but I went back and looked
at my notes and there was only a little blurb about it.
I still
think ESRI is a little skimply on Geoprocessing operations. Seems like
this would be a major component of any curriculum.
There is book
called ""Practical GIS analysis"" which has helped out a lot. It is not
""Esri specific"" but it pretty much uses the same command as you would
in ARCINfo. This book has helped clarify a number of different overlay
analyses.
Anyways, thanks a lot and I'm still looking for that polygon that did NOT get cutoff.

"

[ELeFevre]

"

Erin,
My mistake, YOU HAVE TO SELECT something in order to clip.
Sorry.

http://

Yes, if you select the layer you want to clip this will work! Still,
I think there is probably a much better way to do this directly in
ArcGIS. The method I used is suitable if you only have a few polygons
you need to clip. If you had several hundred or thousand, it could get
a little tedious selecting and clipping each one. Frax's method would
probably be the most efficient... "

[benbakelaar]

"

Anyways, thanks a lot and I'm still looking for that polygon that did NOT get cutoff.

http://

You can look at this JPG I made to see where. [url="http://"http://216.73.153.114/Araki-gis1.jpg"]http://216.73.153.114/Araki-gis1.jpg[/url]

When I tried to do a union of the two layers (not the intersects), I got this error:

Reading Features...
Cracking Features...
Invalid Topology [INCOMPLETE_VOID_POLY]
Failed to execute (Union_2).

Which leads me to think that the area I have circled in the picture above is an incomplete polygon.

I
think if you did a union like frax suggests, and then use Erin's method
to subtract the PolygonBoundaries layer (with all polygons selected),
that would be the quickest. I know the documentation and some people
here have said CLIP will work, but I still don't believe it works as a
""subtract"" function. According to the help description, which I think I
posted above, it is exactly the same as INTERSECT.

And if anyone
cares to answer, what is the deal with all these ESRI productS? I now
understand ArcMap (its ArcView), ArcToolbox (OK fine, throw your tools
in a separate program), and ArcCatalog (actually I find this useful).
But what is ARCInfo? And what is ARCGIS (except a family of products,
i.e. Microsoft Office)? I get confused when people say they are using
ArcGis 9.1. But hey, I guess it's the same as saying MS Office 2003. "

[frax]

ben,
ArcInfo/ArcEditor/ArcView depends on how much functionality you have
enabled in ArcMap/ArcToolbox/ArcCatalog. ArcInfo also adds workstation
etc. To make things more complicated you also have the extensions, like
Spatial Analyst...

On the Union thing, this is how I would do
this operation. I haven't done it in ArcMap/ArcToolbox, so I can't give
you the complete steps, I usually do things like this in ArcInfo WS.
* Union the two layers and merge the attributes
* Now you can look at the attributes and then select which polygons are inside/outside.

[ELeFevre]

"

And if anyone cares to answer, what is the deal with all these ESRI productS?

I've
come to appreciate the independant programs of ArcGIS. It sure beats
the kitchen sink approach of programs like Autodesk Map 3D which I use
use along-side ArcGIS at work. Even the simpliest tasks in Autodesk can
lead one to the help files. I only wish ESRI would offer a stripped
down version of the application (similar to Arcview) at a reasonable
price to their extensive product line.

Back on topic:
Is
there a way to select the shared polygons using the Select by Location
tool? I've been trying and still come up empty handed... "

[David T]

I apologize for my delay in getting here to respond to this topic. I've been out ill the last few days.

I
wrote up a quick 'how-to' to do something like this. This should work
for you. I'm cutting and pasting this from a slightly different
application of this same technique, but I'm sure you can figure out how
to apply this to your situation.

I've used this technique to
create a few maps of my military installation. It's been especially
useful when I've created some shaded relief maps, scale back the shaded
relief that falls outside my installation. I use this effect mostly
because I have really detailed shaded relief for my installation, but
not as detailed relief for the areas outside. Without using this
technique, there is a noticable difference in the two relief graphics.
With this technique, the map reader doesn't see the difference. (Keep
in mind that our detailed shaded relief extends beyond the boundaries
of my installation, but doesn't extend to the entire area of the map).

Having said all of that - I use ArcGIS 8.3, and have a quick write up for you (and others) to follow:

1. In ArcMap, load the polygon of your boundary.
2.
In ArcCatalog, create a new polygon layer (either a shapefile or
geodatabase feature class). Bring this newly created layer into your
ArcMap session.
3. Begin editing your new layer. Draw a polygon that
encompasses your boundary, and matches or exceeds your area to be
mapped. Save your edits and stop editing.
4. Use the Geoprocessing
tools. Use the 'Union Two Layers' tool. Select your new layer as your
input layer, and your boundary as your overlay layer. This creates a
new shapefile (or geodatabase feature class) (called Union_Output) that
contains two polygons - one for the area inside your boundary, and one
for the area outside your boundary.
5. Edit the newly created union layer (Union_Output), and delete the inside polygon. Save your edits, and stop editing.

You
now have a shapefile that contains a 'cut-out' of your boundary, and
allows you to mask out the areas outside of the boundary.

If you need additional assistance, go ahead and post.

[David T]

"

And 
if anyone cares to answer, what is the deal with all these ESRI 
productS? I now understand ArcMap (its ArcView), ArcToolbox (OK fine, 
throw your tools in a separate program), and ArcCatalog (actually I 
find this useful). But what is ARCInfo? And what is ARCGIS (except a 
family of products, i.e. Microsoft Office)? I get confused when people 
say they are using ArcGis 9.1. But hey, I guess it's the same as saying 
MS Office 2003.

http://

Just to go off the original topic for a moment...

ArcGIS
is the family of products. Within ArcGIS, you have three main programs
- ArcView, ArcCatalog, and ArcToolbox (at ArcGIS 9.0, ArcToolbox is
integrated into ArcView, and no longer stand-alone).

Think of
ArcCatalog as your 'Windows Explorer' for GIS tool. ArcView is the
primary program. Within ArcView, you have levels of functionality -
ArcInfo, ArcEditor, ArcView. It depends upon the licensing you buy, and
the level of complexity you need. What confuses things even more, is
the old ArcInfo Desktop, which is a command line interface. And, of
course, ArcView 3.2, which is the 'old', 'basic' version of GIS.

Basically ArcInfo is the 'highest' level of functionality. A lot of people can get away with using ArcView without a problem.

Generally, you can say both 'I use ArcGIS 9.1' and 'I use ArcView 9.1', and it will mean the same thing. "

[David T]

"

Back on topic:
Is 
there a way to select the shared polygons using the Select by Location 
tool? I've been trying and still come up empty handed...

http://

What
about using the Select By Location that 'touch the boundary of'? Unless
I'm not following exactly what you're trying to do. But that should
take care of those areas that fall both inside and outside of a
bounding polygon.

(I'll admin that I don't use the Select By Location tool very often, as I prefer to select by attributes). "

[araki5]

"

And if anyone cares to answer, what is the deal with all these ESRI productS?

I've
come to appreciate the independant programs of ArcGIS. It sure beats
the kitchen sink approach of programs like Autodesk Map 3D which I use
use along-side ArcGIS at work. Even the simpliest tasks in Autodesk can
lead one to the help files. I only wish ESRI would offer a stripped
down version of the application (similar to Arcview) at a reasonable
price to their extensive product line.

Back on topic:
Is
there a way to select the shared polygons using the Select by Location
tool? I've been trying and still come up empty handed...

http://

Erin,
I
basically used the approach that Ben outlined. When u use the ERASE
tool(on Xtoolspro) it will ""cut"" the polygons that are both in/out of
the boundary's.
Give that a shot. Be advised, the polygons that get cut depends on the order that you choose for the input shapefiles.
"

[pghardy]

"

ArcGIS is the family of products.

Correct,
but it's a bigger family than you indicate - the term 'ArcGIS' includes
the ArcGIS Desktop, but also ArcGIS Server, plus the developer
environment based on ArcGIS Engine.

If we concentrate on ArcGIS
Desktop, as it is what most people here would use, it comes in three
licence level products, called ArcView, ArcEditor, and ArcInfo, with
increasing levels of functionality. Note that ArcView is intended
primarily as a viewer and exploration tool, and it is the ArcEditor
level that is aimed at professional creation and manipulation of data,
and at cartographic production. ArcInfo is the top-end level, aimed at
heavy analysis and bulk processing.

Simplistically, you don't buy ArcGIS, you buy ArcView, or ArcEditor, or ArcInfo.

Within 
ArcGIS, you have three main programs - ArcView, ArcCatalog, and 
ArcToolbox (at ArcGIS 9.0, ArcToolbox is integrated into ArcView, and 
no longer stand-alone).

Not quite - the main components (Desktop Applications) of ArcGIS 9.1 Desktop are ArcCatalog, ArcMap and ArcGlobe.

Think of ArcCatalog as your 'Windows Explorer' for GIS tool.  ArcView is the primary program. 

Better to say that ArcMap is the primary program.

Within ArcView, you have levels of functionality - ArcInfo, ArcEditor, ArcView. 

... Within ArcGIS Desktop, you have ...

It depends upon the licensing you buy, and the level of complexity you need.

Agreed.

What confuses things even more, is the old ArcInfo Desktop, which is a command line interface.

Referred to these days as ArcInfo Workstation.

And, of course, ArcView 3.2, which is the 'old', 'basic' version of GIS.

This is sufficently old that it predates the ArcGIS concept.

Basically 
ArcInfo is the 'highest' level of functionality.  A lot of people 
can get away with using ArcView without a problem.

It depends what the task is, and for production cartography, then ArcEditor would often be more appropriate.

Generally, you can say both 'I use ArcGIS 9.1' and 'I use ArcView 9.1', and it will mean the same thing.

Generally
a company will say ""we use ArcGIS 9.1"", while a particular operator may
say ""I use ArcView 9.1"", or may say ""I use ArcEditor 9.1"", or I Use
ArcInfo 9.1""

Sorry about the length of this reply, but casual
use of nomencature is a source of confusion, and I think it helps if we
try and use the standard terms.

Final comment - what I say is a brief summary of my understanding - see [url="http://"http://www.esri.com/products.html"]http://www.esri.com/products.html[/url] for the full story.

"

[Martin Gamache]

"

It depends what the task is, and for production cartography, then ArcEditor would often be more appropriate.

Unless
you need good labelling (sorry Paul I can't quite drop this one)and
thus Maplex in which case ArcInfo or Maplex alone it is. If you don't
need Maplex, then I think Arcview with the Ianko Edit Tools suite is a
fairly powerful set of tools (for cartography) at a much better price
point than ArcEditor and the support from Ianko is quite good. "

[pghardy]

"

Unless 
you need good labelling (sorry Paul I can't quite drop this one)and 
thus  Maplex in which case ArcInfo or Maplex alone it is. If you 
don't need Maplex, then ...

No
it isn't You can add the Maplex label extension (""Maplex for
ArcGIS"") to ArcView, or ArcEditor, or ArcInfo. From 9.1 it comes free
with ArcInfo, but you can still add it to the other two.

...
I think Arcview with the Ianko Edit Tools suite is a  fairly 
powerful set of tools (for cartography) at a much better price point 
than ArcEditor and the support from Ianko is quite good.

Don't
get me wrong - ArcView is a great piece of software, and is quite
sufficient for some kinds of cartography (e.g. thematic presentation),
or for collating geodata to feed shape files into Illustrator if that
is your principal cartography tool (as it often is currently for the
individual cartographers posting here).

However, if you want to
work as part of team sharing data, or take advantage of topology, or
save time using a richer set of processing tools, then ArcEditor
provides those functions (and more) as well as everything in ArcView.

Importantly
for people in this forum, creating and editing the new cartographic
representations and overrides coming in 9.2 requires an ArcEditor level
license.
"