GIS Tips & Tricks

Google Style for ArcMAP

2006-06-04T20:42:00.000-07:00

If you are a Google Maps lover and want to mimic the Google style in ArcMAP check out Brady Davis's blog conversationswithmyself.com.
He has a GoogleStyle.style that works wicked from ArcMAP 8.3 and beyond.

Here's a screenshot of the googlestyle.mxd sample that Brady includes in his zip file:

Awesome work Brady!

ArcGIS Shortcut Keys

2006-05-31T21:42:00.000-07:00

I always knew about shortcut keys in ArcGIS but as I have been transitioning myself away from command line I had almost started to forget that my keyboard even existed anymore. At a recent training session I was reminded that there are some very useful shortcut keys in the ArcGIS environment. To access a list of shortcut keys in ArcGIS go to ArcGIS Desktop Help and search for 'shortcut keys'. Among others there are shortcut keys for: editing in ArcMAP, common tasks in ArcGIS help, common functions in ArcMAP and you can even customize and create your own shortcuts.

Here's a quick teaser for some of the very common shortcuts in ArcMAP:

The ESRI Online Help is a great reference for keyboard shortcuts as well.

Overlapping Polygons Display Order

2006-02-23T19:42:00.000-08:00

Recently someone asked me how to change the display order of overlapping polygons (like region topology) from an SDE layer in ArcMap. The problem was a smaller polygon underneath a larger one was not shown when the unique values of the dataset were symbolized using a solid fill. Like this:

The solution isn't as intuitive as it could be. For ArcGIS, ArcMAP 9x the display order of the polygons can be changed in > LAYER PROPERTIES> SYMBOLOGY> ADVANCED> SYMBOL LEVELS...>

Check the box next to >Draw this layer using symbol levels specified below and use the up and down arrows on the right to toggle the display order of your polygons layer values.

The polygons are displayed in the order selected in the symbol levels window. See...

For users of ArcGIS 8x the location
of the ADVANCED>SYMBOL LEVELS
menu is a little hidden and is found by
right clicking LAYERS in the
Table of Contents.

Cool Tools continued…

2006-02-01T21:33:00.000-08:00

An anonymous comment on my previous post suggested that I should check out the free ArcGIS extensions from Ianko’s GIS page. The company is now called ET Spatial Techniques and I have actually used their free Easy Calculate tool which is an excellent add-on for ArcGIS ArcView users. From the http://www.ian-ko.com/ website:

EasyCalculate is a set of expressions (currently 110) for the ArcGIS field calculator. The expressions can be loaded in the Field Calculator and when executed calculate some spatial characteristics of the features, edit the shapes, add records to a target layer, draw graphics etc

I haven’t tried Ianko’s other tools yet like ET GeoTools, ET GeoWizards, and EditTools and the other free stuff like the Watershed delineator but it looks like the focus is primarily on enhanced editing and manipulation capabilities as well as surface generation tools for ArcGIS ArcView users. The tools are all available for free demo and the cost to buy seems reasonable at $110 US for EditTools, $140 for ET GeoTools and $180 US ET GeoWizards. As is the case with most software the price goes down with the number of licenses purchased.

One of the things I have found most difficult about the transition from the command line ArcInfo world to ArcGIS is the editing capabilities in ArcMap versus ArcEdit...anything that can make editing in ArcMap more intuitive and easier is definitely worth a try. The next time I have to do some editing I will definitely take a look at Ianko’s GIS page.

Thanks for the tip “Anonymous”…Keep them coming!

Cool Tools from XTools Pro

2006-01-26T21:13:00.000-08:00

I think XTools Pro from the folks at Data East is probably the finest third party extension available for ArcMAP. Not only is it relatively cheap at $150 US for a single license but this feature rich extension is almost indispensible if you are running an ArcView - ArcGIS license. I orginally picked up a license when I was running ArcView - ArcGIS and needed the "identity" spatial overlay functionality. Once I started playing around with some of the other tools I soon wondered how I had managed without it. Some of my favourite functions are: the Aggregate Features/Records which performs an SQL-like group by aggregation query and spits out either a stand-alone table, shapefile or personal geodatabase; Multi-Delete Fields is another cool tool I use frequently which as the name suggest deletes multiple fields with a couple of quick clicks of the mouse; a younger co-worker of mine might call the Feature Report tool 'sick' which I think is hip-talk for really good...the Feature Report tool quickly generates an MS Word editable (not edible) report of a selected feature, showing geometry, projection and feature attributes like the one shown here>>

If you are an ArcGIS user and want to enhance the functionality of your GIS software without breaking the bank you may want to consider XTools Pro. There's even a trial software download so you can try the cool tools before you buy.

You may not believe it by my hyped up rant, but I don't work for or have any affiliation with XTools Pro or Data East.

Creating a Unique ID field in ArcMAP

2006-01-11T21:45:00.000-08:00

The other day my friendly coworker, Karen, asked me if I knew how to create a unique id field for a dataset in ArcMAP. I remembered doing this before but I couldn’t remember exactly how since I typically still use ArcINFO TABLES for this process…I know that some of you may find it tragic that I continue to bang away at my keyboard using command line but somethings are still way more efficient that way. So anyway..to answer Karen’s question I had to consult the mighty ESRI Knowledge Base and as is often the case the question had already been asked.

Basically, you need to add a numeric field and calculate values using the VBA code available at this ESRI Technical Article link…

Hopefully this was helpful Karen?

ArcGIS Scripting Summary

2005-12-22T16:16:00.000-08:00

I just came across this decent ArcGIS scripting summary from the Spatial Analysis Lab at Western Washington University. The summary is good in that it references old school scripting (AMLs, and Avenue) as well as new-school scripting tools (VB, Python & Model Builder) with a brief ‘basic-steps’ guide for beginner GIS code-warriors.

Click here for more information.

This reminds me that I must learn Python in 2006!!

Matching Shade Transparency to Legend

2005-11-14T16:44:00.000-08:00

The first time I saw ArcMAP demoed at an ESRI Users Conference in Victoria was many years ago. I remember thinking how cool the polygon shade transparency was and how I thought it would radically change the way I was mapping. Think of it: transparently shaded themed polygons over orthophotography or satellite imagery…How cool is that? Some months later when I finally got to try ArcMAP I think the first thing I did was transparently theme a land-use zones coverage over some orthophoto imagery. Wow, was I impressed! What was less impressive, unfortunately, was that ESRI seemed to go only half way with the transparency feature. Notice how your legend doesn’t change when you change the transparency of your polygons…Strange isn’t it? Maybe we are waiting for ArcGIS 10x?

Of course GIS wouldn’t be nearly as fun as it is without finding a work around solution to little software annoyances.

Here are two quick options to make your legend shade match your transparent polygons?

From the TOOLS menu select the Eye Dropper tool> Customize> Commands> Page Layout> Eye Dropper
Drag the Eye Dropper to an existing ArcMAP toolbar…I usually ‘drop’ it on the Drawing toolbar.
With the Eye Dropper tool selected click on your transparent polygon. The RGB values of the polygon wil appear.
Select OK and the transparent colour is now added to your colour palette.

Option A

Switch from the Eye Dropper tool to the Select Elements tool…(the arrow tool) and select the legend.
Right click on the legend and select CONVERT TO GRAPHICS.
Right click on the legend again and select UNGROUP. Do this twice to make the label patch a selectable graphic.
Select the patch box to change and use the Fill Colour tool…(the Paint Can) to pick the colour that was created from Eye Dropper step.

Option B

In the Table of Contents select the polygon layer that has had transparency applied to it. Right click the layer and select COPY.
Paste the copied layer back in to the Table of Contents but make sure to turn it off so the layer isn’t displayed twice in the data frame.
In your legend add the COPIED layer to your LEGEND ITEMS and make sure that the check box for ‘Only display layers that are checked on in your Table of Contents’ is UNSELECTED.
Right click the COPIED layer in the Table of Contents again and select PROPERTIES> SYMBOLOGY> match the colours in your copied layer to the colours created with the Eye Dropper tool.

Realistically the above methods are practical if you only have a handful of polygon themes with transparent shades. Also I wouldn’t suggest matching your legend to your transparent shades until you have fully committed to using those colours.

New-School Editing in ArcMAP

2005-11-14T13:23:00.000-08:00

I admit that I still edit using old-school ArcEdit, but I'm slowing learning the benefits of the new-school tools as well. For ArcMAP editing neophytes like me, here's a useful link (pdf) to an article describing 11 useful tips and tricks for editing in ArcMAP.

Topics covered include:

Modify feature selection by individual layer.
Select the desired feature from overlapping selectable layers.
Prevent selected features from being moved accidentally.
See the feature type or layer currently affected by the active
snap agent.
Control which features snap.
Override snapping environment settings.
Toggle between the Sketch tool and other editing tools using
shortcut keys.
Use units different than the map units when specifying
distance for a sketch segment.
Cut polygon features based on a specified distance from a line
feature.
Rotate a selected line feature on one endpoint and snap the
other endpoint to another feature.
Explore a map in detail and perform edits without changing
the map display scale.

Handclaps to Colin Childs and Keith Mann, ESRI Educational Services for writing this article.

Fixing Broken Data Links in ArcGIS 9

2005-11-14T11:21:00.000-08:00

Don’t you hate it when you open an existing MXD file in ArcMAP and those red exclamation marks next to your data layers indicate you have broken data links.

Of course you can always update the data source links individually: Right click on the layer> Properties> Source > Set Data Source…

But if there are a wack of broken data links the above method can be extremely tedious. What if a bunch of GIS data has been moved during some crazy corporate data reorganization? Fortunately, since ArGIS 9, the wise minds at ESRI have made it possible to fully fix broken data links outside ArcMAP in the ArcCatalog environment.

Here’s how:

1) Fire up ArcCatalog
2) Navigate to your .MXD file
3) Right click on the .MXD
4) Select Set Data Sources…

The Set Data Sources window will pop up allowing you to change data sources individually under >New Data Source > Or you can > Select All and change the data sources using a Find and Replace method similar to what you would find in MS Word, Notepad etc… Thank goodness for ArcGIS 9.

Add Date, Time & File Name Stamp to an ArcMAP Layout

2005-10-26T10:53:00.000-07:00

I have never figured out why there is no INSERT DATE option in ArcMAP. Maybe it's just me but normally I put a DATE on my layouts. Isn't it a cartographic standard?

Fortunately there are a many ArcScripts out there that allow you to add a DATE STAMP to your layout and they usually include a FILE NAME option as well.

The organization I'm currently GISing for has admin rights really locked down so registration of .DLLs for Tool Controls is difficult. Luckily I was able to find a Date Stamp script at the ESRIs ArcScripts site that's creates a button control that allows you to add a text box for Date, Time, & File Name on your map. It's opensource code too which means it's easy to customize for your own enjoyment. Use this link to download the zip file to your PC and follow the instructions in the txt file.

Once installed you'll have a date stamp icon on one of your toolbars.

When added to your map the fully manipulable textbox will look something like this:

Wednesday, October 26, 2005 11:24:00 AM
C:\somedirectory\thenameofyourmap.mxd

Kudos to Jonathan Garner for creating this script.

Georeferencing an image in ArcMAP

2005-10-24T16:06:00.000-07:00

Scenario: Someone gives you a hardcopy map with a couple of polygons hand drawn on it. They want it in the GIS so you can make a pretty map for them and run some analysis. What do you?

In my opinion, you bascially have three options:
1. Use a digitizing tablet;
2. Eye-ball it off the map – often called ‘heads-up digitizing’ or ‘on-screen digitizing’; or
3. Scan the map, georeference the image and trace the polygons.

I’m going to quickly run throught the third option. For fun let’s call this geotracing. If you don’t have a digitizer it’s probably the best option…besides I’ve never been a fan of the on-screen digimonkey thing.

So as I mentioned above you’ll need to scan the map. Hopefully there aren’t too many maps and the polygons are concentrated in smaller areas that fit nicely on your scanner. I would recommend scanning to JPEG or TIF either will do fine.

Okay now that you have your images saved let’s fire up ArcMAP and launch the GEOREFERENCING toobar. Right click on the main toolbar and select Georeferencing.

Add some topographic layers to your ArcMAP document. Depending on your map, normally roads, water features and contours will work well.

Add the image you want to georeference. Don’t worry about ArcMAP complaining about the image missing a spatial reference information.

Using the Zoom tools roughly navigate to the area where the polygon should be added.
On the Georeferencing toolbar select> Fit to Display

As a personal preference, I also like to have Auto Adjust selected.

Your image should now be visible behind your layer features.

Select the Add Control Points button.

Begin adding control points linking features on your image to the GIS layers. As you add more control points the image will begin to morph and shift to the correct location.

If you added an unlucky control point that you wish to remove you can deleted in the Link Table. Beside the Add Control Points button select the View Link Table button. Select the link you wish to remove and hit the delete button.

Once your are satisifed with how your image lines up to your spatial data, you may wish to save the rectified image. Georeferencing> Rectify… > Save. The rectified image will be saved as a TIF.

Now that the source image is rectified it’s simply a matter of tracing or ‘geotracing’ the polygon(s) of interest. To do this I create an empty polygon shapefile. ArcCatalog> Right Click> New> Shapefile> Name it and select feature type> Polygon. If you know the spatial reference information it would be a good idea to EDIT that information here as well.

Now that you’ve created an empty polygon shapefile, add it to ArcMAP, Start Editing on the EDITOR toolbar and ‘Create a new feature’ by geotracing the polygon on your georeferenced/rectified image. Save Edits, stop editing, et Voila! You probably want to add fields and attribute information to the new polygon(s) but you already know how to do that…don’t you?

Custom Legend Patch Shape

2005-10-24T13:41:00.000-07:00

Want to make your own custom legend patches in ARCMAP to match polygon or linear features? Here’s how…

In ArcMAP choose TOOLS>CUSTOMIZE

From the Customize menu select the COMMANDS tab. Select the Page Layout Category and choose the New Legend Patch Shape. Drag the tool to your favourite toolbar.

Click the New Legend Patch Shape button. The New Legend Patch menu will appear. Select Area or Line. Select the layer to use in Patch Shape and whether the features to create the patch will be all, visible or the selected features. Click Create Patch> Click Add to Styleset and specify a name for the new patch. Click OK.

Now that you’ve created your new patch it will available for you to use via the Legend Wizard patch selector. Enjoy!

ArcMAP Symbols

2005-10-24T12:51:00.000-07:00

Here's a great link to ESRI's ArcMAP symbols in their vast styles catalogue.

Suggestion: Download the PDFs, print them out and decorate your cubicle!

Multi-Lined Legend Labels in ArcMAP

2005-10-24T10:48:00.000-07:00

PROBLEM: legend label too long to fit in legend area without reducing font size.

SOLUTION: use the label DESCRIPTION option instead where multi-line label descriptions are possible. See below>

Select Edit Description…
The Description for Legend input box will appear. Enter the label description here. For a new line use CTRL-ENTER. Select OK.

Right click on the legend and bring up the legend properties

Select the ITEMS tab. Right click on the layer in Legend Items: and select Properties…

The Legend Item Properties box will appear>

Unselect the checkbox for Show Labels and select the check box for Show Descriptions. Click the Description Symbol… button.

Description text is by default italicized. Unselect the and select OK.

Here's the RESULT: