GIS Pathway... » Shapefile

Create Thumbnails in ArcCatalog

Timothy — Mon, 18 May 2009 14:15:55 +0000

ArcCatalog has so many features, it is difficult to keep up with them all. One that is very helpful is the Create Thumbnail button. This allows you to create a thumbnail image of a file so that it can be viewed from the Contents Tab instead of the default thumbnail. The below example shows its application for a shapefile, but this can be applied to a variety of file types. This quick snapshot can help the browsing process when you are looking for that certain file.

Follow these simple steps to create a thumbnail image for a file in ArcCatalog:

1. View the shapefile with the Preview Tab.

2. Zoom to desired view.

ArcCatalog gives you a few navigation tools. You can create a full extent view or zoom in on certain features.

3. Press the create thumbnail button from the toolbar.

4. View the newly created thumbnail under the Contents Tab.

Learn more about ArcGIS in these excellent books:

GIS Tutorial

Getting to Know ArcGIS

Show Area Vetices while Editing in ArcMap

Timothy — Fri, 13 Feb 2009 02:07:54 +0000

Finding a vertex to snap to can be very challenging while editing. With snapping turn on, you can slowly more your cursor along the desired path and the cursor will snap to the nearest vertex. Although this can be affective, there is a great risk that a vertex may be missed. Showing the vertices within the area of you cursor can help you find all vertices while preventing gaps from forming within the data.

Simply press [V] to show the vertices in the area of the cursor. Remember that you must be editing during this procedure. This saves time and helps you to be more productive while editing in ArcMap. (See Example)

Screenshot of edit session

Screenshot of edit session while using [V]

CAD to GIS Shapefile

Timothy — Thu, 11 Dec 2008 04:55:17 +0000

CAD files are created with extreme detail, but how can you use them in GIS? These files do not work quite like GIS feature classes or shapefiles in spatial analysis. They can be converted to a usable format through a few basic steps.

Add CAD file to ArcMap
Select by Attribute desired layers
Export selected features to shapefile or feature class
Add new layer to map

You can also use ArcToolbox to convert from CAD

ArcToolbox -> Conversion Tools -> Import From CAD
Select Input CAD File
Input New Geodatabase Name
Select Coordinate System (optional)
Click Ok

Here is a video for further demonstration.

Note: Videos are broadcast through youtube.com. Some browsers may block this content.

ESRI also has some good courses for working with CAD files in GIS on their training website.

ArcGIS Geodatabase Benefits

Timothy — Thu, 04 Dec 2008 02:57:20 +0000

I was just recently doing a spatial join between a polygon shapefile and a point feature class file. There were approximately 400 polygons and 38,000 points. There were several fields within the point file which were being summarized based upon which polygon they fell within. The entire join process took about an hour. I then took the output file, which was a geodatabase polygon feature class and joined it to a similar point file. Amazingly, that join process only took 5 minutes.

This is just one example of the efficiency of the Geodatabase. Geoprocessing is so much quicker. A savings of time is a savings of money. Here are a few other things to know about the various types of geodatabases.

Personal Geodatabase

Single User Editing
Stored in Access Database File
2 GB Max Size

File Geodatabase (ArcGIS 9.2+)

Single User Editing
Stored in a Folder
Efficient Data Structure for Increased Performance
1 TB per Table Max Size

SDE Geodatabase

Multiuser Editing
Disconnected Editing
Stored in a RDBMS

Additionally, with the geodatabase you can create:

Topologies
Geometric Networks
Feature Linked Annotation
Relationship Classes
Sub Types and Domains
A Centralized location for all the geographic data

So with these benefits of the geodatabase, try converting some of your data. Creating a geodatabase does not take long as you can find out in my 90 Second Geodatabase post. Also, ESRI has a great blog post entitled: Migrating your existing data into the Geodatabase. It goes into great detail into how to import the following file types into the geodatabase.

Shapefiles
Coverages
CAD
Tables
Imagery

Try out the geodatabase today, you will find many benefits. If it seems a little awkward, give it time as you will get adjusted to the concept. There is nothing to loose. If you don’t like it then delete the geodatabase and go back to using your shapefiles.

Good Luck!

Related Website Pages

File Format Support in GeoCommons – Do Geodatabases Make Sense?

Five reasons why you should be using the File Geodatabase

Modeling Our World: The ESRI Guide to Geodatabase Design

Calculate Lat/Long for Shapefile

Timothy — Fri, 31 Oct 2008 03:27:47 +0000

Ever needed to add XY or Latitude/Longitude values to you shapefiles or feature classes? Well, what seems to be a mystery can easily be done with just a few clicks.

The easiest way to get the lat/long values is to right click the field and select “Calculate Geometry…”. You can define whether to calculate x or y along with other geometries too.

Here is a more extensive video tutorial.

Note: Videos are broadcast through youtube.com. Some browsers may block this content.

Learn how to add XY data to a map here:

Create Point File from XY Data