Posts Tagged ‘arcmap’

Blog holiday, 3 year anniversary

Tuesday, August 24th, 2010

See me in person in Portland when I keynote WhereCampPDX the weekend of September 25; Barcelona for FOSS4Geo; or Borsa, Romania for the Int’l Mountain Cartography conference. I’ve got a few projects I need to wrap up and start this Fall so please expect only intermittent updates rather than daily digests.

Over the last three years (almost to the day), I’ve had more than 600,000 pageviews in this space, from original pieces like Meet Toni Mair — Terrain Artist Extraordinaire to promoting other’s work like Public Art in Google Street View (Good Mag). I’ve tooted my own horn on projects like Create Calendars Automatically in Illustrator: Version 5 (Kelso) and helped folks with Freehand and VBA in ArcMap. I have two more big posts planned the next several weeks, so don’t unsubscribe quite yet ;)

In the meantime, I will continue to tweet @kelsosCorner, the micro-blogging service. A sample of Twitter posts is featured in the upper right sidebar on this page.

Calculating bounding box in ArcMap

Monday, July 12th, 2010

xmindimen

[Editor’s note: I keep returning to this technique for calculating a feature’s extent (minimum bounding rectangle) in ArcGIS using the Field Calculator. Thanks William and Jeff!]

Republished in part from ESRI Forums.
Sample Field Calculator code for computing XMIN appears below.

Information about shape properties appears in the “Geometry Object
Model
” diagram (pdf). All four parameters are Xmin, Xmax, Ymin, and Ymax.

dim Output as double
dim pGeom as IGeometry

set pGeom = [shape]
Output = pGeom.Envelope.XMin

The ESRI UC ArcGIS 10 Q&A Response Is Up (James Fee)

Friday, July 9th, 2010

jmf-where20-2009-sidebar[Editor's note: As the GIS community prepares for the just released ArcGIS 10 and gathers for the annual User Conference in San Diego, Ezree cum E.S.R.I. has posted a Question and Answer FAQ about the new release. Notable to me: Visual Basic for Applications (VBA) is resurrected for the last time, time to learn Python! James Fee translates from corporate speak.]

Republished from Spatially Adjusted.

One of the best insights into ESRI and their direction is the UC Q&A. ESRI has posted the latest one here and some highlights are below:

Q: What has ESRI done in the area of map books?

A: At ArcGIS 10, functionality has been added to allow you to create map books using a feature layer to define map extents for multiple pages. This new functionality, in conjunction with all the other enhancements to support map books, is referred to as data driven pages. Data driven pages give you the ability to generate multiple pages by taking a single layout and iterating over a set of map extents. Any feature layer, point, line or polygon can be used, along with a margin, to define the extents.

A question I still get asked again and again is when is ESRI going to update DS Mapbook. Well now you’ve got a real solution built into ArcGIS 10.

Q: Does ArcGIS 10 open up more functionality for use with Python?

A: Python integration is one of the key features of ArcGIS 10. At this release we’ve introduced a new Python subsystem called ArcPy, which exposes many of the ArcGIS functions.

ArcPy is still a little kludgy, but wasn’t isn’t with ArcGIS 10.

Continue reading at Spatially Adjusted . . .

Review of new tome for map projections: Lining Up Data in ArcGIS (Vector One)

Thursday, June 24th, 2010

lining-up-data-sm[Editor’s note: No PRJ file? No problem. Use this new guide by M. Maher from ESRI Press to learn map projection basics and the ArcGIS commands (versions 9 and 10) that register map data to common coordinate spaces. Read the first chapter and table of contents at ESRI.]

Republished from Vector One.

Lining Up Data in ArcGIS – a guide to map projections is a new book from ESRI Press. It is authored by Margaret M. Maher. Since I don’t have ArcGIS running in my office I couldn’t try out some of the details provided in the book, nevertheless, I did spend some time running through the book and offer the following comments.

One of the issues that many people encounter with GIS data revolves around projections, coordinates and lining up data with already existing spatial information. I’ve made the mistake myself numerous times, excited to get the data into the system, only to open the map window and finding what I just added from Berlin is placed in Oklahoma, Alberta or the middle of the Mediterranean Sea. How did that happen? Because I never lined up the data properly.

This book is very helpful. It explains how to identify geographic coordinate systems as compared to projected coordinate systems. If you are using ArcMap, then this book will show exactly how to determinine projections and set them. It even provides examples for going to ArcGIS Online, downloading imagery and aligning it properly.

Continue reading at Vector One . . .

ColorBrewer in ArcMap, updated to version 2.0 (via Weary Ramblings)

Tuesday, March 16th, 2010

cb2

[Editor's note: Struggling to pick colors in ArcMap or need to ensure your design meets federal accessibility standards for vision impairment? ColorBrewer.org has been updated to version 2.0 and now a ArcMap plugin brings some functionality right into your GIS. It's not clear to me if the "Terrain overlay" option for previewing the colors takes into account the muted nature / secondary HSV mixing of the colors, I don't recommend using that part just yet.]

Republished from National Cancer Institute.
Seen at Weary Ramblings.

ColorTool is a plugin for ArcMap™ (part of the ESRI ArcGIS Desktop suite) that helps users create choropleth maps using ColorBrewer color ramps.

The program runs from a button in the toolbar and opens a form that guides the user in choosing a classification scheme. For more information on the color options, visit ColorBrewer.org. ColorTool supports Quantile, Equal Interval, Natural Breaks (Jenks), and Unique Value classification types.

Download the ColorTool plugin . . .

Along with the plugin, the main ColorBrewer site has been upgraded to version 2.0

Republished from Free Geography Tools.

ColorBrewer is an online Flash app designed to help select appropriate data coloring schemes for maps, including sequential (choropleths), diverging (data with break points), and qualitative (discrete categorical data). I’ve covered version 1.0 before, and now ColorBrewer 2.0 is out. Not a huge number of functional differences, but some useful additions (and one disappointing subtraction):

  • More parameters are selected by drop-down boxes instead of buttons; bit faster this way
  • All controls are on the left side, making them easier to find
  • You can now choose between a colored background and a terrain background
  • Color transparency can now be set between 0 and 100%
  • More choices for background, road, city and border colors
  • You can now screen color schemes by appropriateness for color blindness, photocopying and print. In version 1.0, you only had icons showing which uses were appropriate, and these are still available in the “Score Card” tab at lower right
  • More options for color scheme export directly from the program, including an Excel file of all available color schemes, export in Adobe Swatch Exchange format (ASE), and in-program text hex color codes for copying and pasting into graphics programs.
  • No more map zoom; I miss this option.

What is GeoDesign and why is it important (ESRI + GeoInformatics)

Monday, March 15th, 2010

[Editor’s note: Like mashups, but in ArcGIS and analytical without programming skills. Sounds like CommunityViz but is more generally the “pairing of design and GIS. It unites the art and creativity of design (planning) with the power and science of geospatial technology. As one, GeoDesign can produce more informed, data-based design options and decisions.” This drive will introduce modeling, sketching, and feedback capabilities in ESRI’s ArcGIS Desktop 10, set for release in the second quarter of 2010. Looks like it will rely more on GIS services (web apps and 2) and more validating of resulting feature topology by GIS techs. Recently concluded mini-conference on GeoDesign has streaming video clips. This article is also good. Thanks @geoparadigm and @gisuser.]

Republished from ESRI and GEO Informatics.

What is GeoDesign?
GeoDesign is a set of techniques and enabling technologies for planning built and natural environments in an integrated process, including project conceptualization, analysis, design specification, stakeholder participation and collaboration, design creation, simulation, and evaluation (among other stages). “GeoDesign is a design and planning method which tightly couples the creation of design proposals with impact simulations informed by geographic contexts.” [1] Nascent geodesign technology extends geographic information systems so that in addition to analyzing existing environments and geodata, users can synthesize new environments and modify geodata. Learn more about GeoDesign on Wikipedia.

Read more at ESRI ArcWatch . . .

Jack Dangermond on GeoDesign:
“In January [ESRI hosted] the first GeoDesign Summit. It will bring people from both the GIS and design fields together and have them share their work and get a conversation going. I’m not totally sure what the outcome is going to be, but I’m hoping a new profession or direction will emerge. I think we need this kind of mixing at this point to bring these two fields together; people who design the world with people who design the future. Today, geography lives very well in its world and designers live very well in their world, but there’s not this cross-mixing. I believe the outcome will be much enlightened ways to do development; ways that bring science into how we design things: cities, the environment, highways, everything that we do. Today we certainly see the need for this all the way from global warming to designing more livable and sustainable cities. We need more geographic thinking in the way we make decisions. GeoDesign is an attempt to try to do something about that.”

Read more at GEO Informatics . . .

What does it mean for GIS discipline:
“It is not so much that geodesign is new, but rather that technology has reached a point that allows artists to participate in the geodesign process – without becoming technologists.” (Kirk at GeoThought) It still requires good (accurate, precise) base maps and themes in GIS to enable smart decision making (geodesign) on the desktop and in the cloud (web apps). Instead GIS techs being puck jockeys, the planning folks will be able to use the GIS directly, or it’ll seem that way to them ;) I used to work somewhere where the boss had desktop design apps installed and he could comp out designs, but they still had to be rebuilt to production specs. My guess is the same will be true with GeoDesign for a good bit yet. Meanwhile, focus on core competencies.

Learn more at the ESRI Developers User Conference later this month . . .

Services, Resources and Tools for Mapping Data (Sunlight Foundation)

Wednesday, February 24th, 2010

[Editor's note: Listing of several dozen free web apps and tutorials, including GeoCommons Maker!, Modest Maps, Color Brewer, Open Layers, and Batch GeoCoder.]

Republished from the Sunlight Foundation.
By Kerry Mitchell on 02/19/10

Services, Resources and Tools for Mapping DataLong ago, putting together a map of data points would be the sole domain of a skilled GIS practitioner employing an application like ArcView. These days, particularly with the advent of Google Maps, Yahoo Maps and OpenStreetMap, et al., there are a multitude of options for an individual to employ in displaying data geographically. Of course, there are, and will always be, technical options that require some level of programming chops. Fortunately, the pool of drop dead easy implementations that anyone can throw together with ease has grown a lot over the last few years. Then, there is the growing middle ground, lying somewhere between easy but rigid and difficult but flexible. Personally, I tend to hover in this netherworld, leveraging existing code, services or tutorials when possible but occasionally finding myself diving into the more technical areas when necessary and learning a lot in the process.

For those of you out there who might be interested in mapping data, I’ve put together a collection of links to a variety of services, code samples, resources and tutorials I’ve found useful in the past. These links range from new services that barely require anything more than a spreadsheet to complicated frameworks that require a great deal of technical knowledge. This is by no means all encompassing and if you happen to have additional links you’d like to share, feel free to leave them in the comments.

Continue reading at the Sunlight Foundation . . .

Time Awareness in ArcGIS 9.4 Leads to Better Understanding of Complex Geographies (ESRI)

Thursday, January 7th, 2010

[Editor's note: In the next release of ArcMap, due this summer, ESRI takes cues from Google Earth and adds a "time slider" to easily visualize time series in GIS.]

Republished from ArcNews (Winter 2009/2010).

Visualizing Time in GIS

In his First Law of Geography, noted geographer and cartographer Waldo Tobler states, “Everything is related to everything else, but near things are more related than distant things.”

GIS professionals are well versed in visualization of spatial relationships and dependencies, of the proximity of near things and distant things, as in things you can measure with a ruler or with mile markers. But often when studying geography and looking for relationships and dependencies, equally important is proximity in time, as in something that can be measured with a watch or calendar.

click to enlarge
You can control visualization of temporal data in ArcGIS 9.4 using the new “time slider.”

Pioneering environmental planner Ian McHarg is widely known in the GIS community as the “discoverer” of overlay theory, the base theory behind GIS. Another of McHarg’s discoveries—perhaps lesser known, but equally important—is chronology, or the placing of geographic layers in chronological sequence to show relationships, dependencies, and causation through time. “We found the earliest events, mainly of geological history, had pervasive and influential effects, not only on physiography, soils, and vegetation, but also on the availability of resources,” McHarg states, describing an environmental planning study in the 1960s, in A Quest for Life. He calls his discovery of chronology—the order or sequence of features through time—”. . . a most revelatory instrument for understanding the environment, diagnosing, and prescribing,” a construct that leads to a deeper understanding of structure and meaning in the landscape.

click to enlarge
Charles Joseph Minard’s 1869 flow map of Napoleon’s 1812 Russian campaign is a classic example of spatiotemporal visualization (Image Source: Wikimedia Commons).

Chronology is enabled by temporal data. Temporal data is data that specifically refers to times or dates. Temporal data may refer to discrete events, such as lightning strikes; moving objects, such as trains; or repeated observations, such as counts from traffic sensors.

Depicting spatial change over time is a four-dimensional problem, and visualizing temporal phenomena on a two-dimensional map has always been a challenge. The simplest approach is the map series, where individual maps of geographic conditions at certain points in time are presented individually, in chronological order.

Other inventive methods of visualizing change over time and space include creative symbolization, such as in Charles Joseph Minard’s famous map of Napoleon’s march across Russia.

Temporal GIS is an emerging capability for integrating temporal data with location and attribute data, enabling temporal visualization and ultimately temporal analysis. Visualizing change on a computer screen in a GIS environment may give the viewer more options, but it is still a challenge. A simple yet highly effective method of visualizing time in GIS is through animation—displaying a series of maps in rapid succession on the screen.

click to enlarge
A creative method of representing temporal datasets in GIS developed by the Earth and Environmental Science Division at Los Alamos National Laboratory (ESRI Map Book, Volume 19).

“The eye and brain are enormously efficient at detecting patterns and finding anomalies in maps and other visual displays,” says Michael Goodchild of the University of California, Santa Barbara. “GIS works best when the computer and the brain combine forces and when GIS is used to augment human intuition by manipulating and displaying data in ways that reveal things that would otherwise be invisible.” Building a robust temporal capability into GIS provides the human eye and brain with powerful visual tools to help determine the reasons why things happened in space-time. It is also key to modeling and predicting things that might happen in the future.

The new time-aware functionality in ArcGIS 9.4 lets you

  • Create and manage time-based data.
  • Display and animate temporal datasets.
  • Publish and query temporal map services.

click to enlarge
The user interface in ArcGIS 9.4 lets you set time properties for one or more layers.

ArcGIS 9.4 makes temporal mapping simple and easy; enables temporal data management, exploration, and visualization; and creates a strong foundation upon which sophisticated temporal geoprocessing tools and workflows can be built in the future. As McHarg states in To Heal the Earth, “Processes, laws, and time reveal the present.” And once we have the tools and techniques in place to fully grasp how the past has created the present, we can use these same tools and techniques to shape our future.

More Information

For more information, visit www.esri.com/whatscoming.

VBA Field Calculator Tips in ArcMap (Kelso)

Tuesday, November 24th, 2009

fieldcalculator2I’ve been relying on the Advanced logic options in ArcMap’s Field Calculator to wrap up Natural Earth Vector. Because of the diacritical (accent) marks present on many placenames around the world, care must be taken to ensure they don’t get corrupted.

With basic SHP files, I often edit thematic data in Excel and then join it back with the SHP. However, Excel mangles diacritical marks, especially if you’re going cross platform between the Mac and PC. Even when everything is setup right, ArcMap the get Info panel displays ? marks for many diacriticals. The attributes table view shows them correctly, though.

Much of the base data and name attributes are compiled in Adobe Illustrator and exported with MaPublisher using custom scripts I’ve written to take the name from the text that’s been grouped with the feature. This allows contributors who don’t have ArcGIS at home or in the office to take part in the project. Because we often have other attributes (maybe a second name, scale rank, type of feature), I use an “_” underscore character to concatenate these into one string. This string then needs to be parsed back into separate attribute columns.

Note: SHP files use Windows 1252 character encoding. If you’re on a Mac, change your MP export options from “System” to that. If you’re on a PC, you’re already good.

Splitting strings:

In VBA prelogic area (advanced checkmark on):

myString = [ColumnName]
myPosition = InStr(myString , “_”)
myLeft = myPosition – 1

myLen = Len(myString)
myRight = myLen – myPosition
country = Left( myString, myLeft )
provNumber = Right( myString, myRight )

In the field results area: provNumber or country.

Note: If the result is destined for a number formatted column, either caste provNumber as a number or use a temporary holding column that is string formatted, then rerun the field calculator on the number formatted column deriving the value from the temp field. ArcMap with auto-caste for you in that case.

After the jump: Find and replace, counting substrings, hit tests, and changing case.

(more…)

Problems Dissolving in ArcMap, Try Repairing Geometry First

Tuesday, July 14th, 2009

[Editor’s note: I was having trouble last week dissolving a shapefile based on a common attribute. I kept getting the following error: “Invalid Topology [INCOMPLETE_VOID_POLY]“. Not entirely helpful! A little Google searching turned up the following tip from ESRI.]

Republished from ESRI.

Problem:  Some Overlay Tools, such as Intersect, return unexpected results or fail

Description

Results do not look correct or operations fail with strange errors such as:

“Invalid Topology [INCOMPLETE_VOID_POLY]“.

If this type of error has occurred, it is most likely to occur when using one of the following:
Clip, Erase, Identity, Intersect, Symmetrical Difference, Union, Update, Split Featureclass to Coverage, Dissolve, Feature to Line, Feature To Polygon, Integrate, or ValidateTopology.

Cause

It is possible that tool outputs may be strange or incorrect because one or more features in the input feature class have geometry problems. Some examples of geometry problems are:

· short segments
· null geometry
· incorrect ring ordering
· incorrect segment orientation
· unclosed rings
· self-intersections or empty parts

Solution or Workaround

If such errors occur or the output looks incorrect, the first step in assessing the situation is to run the ArcToolbox tool Data Management Tools > Features > Check Geometry. -show me

[O-Image] Check Geometry

This tool provides a list of the invalid features in the feature class and a short description of the problem. Features with problems can be fixed in one of two ways:

  • Editing the feature class with the geometry problem, and fixing each individual problem identified. Some of these problems, like non-simple geometry, can be fixed by double-clicking the feature in the editor and saving the edits.
  • Running the ArcToolBox tool Data Management Tools > Features > Repair Geometry on the feature class containing the problem features. -show me