My World GIS for the Mac
Earlier this summer I made the switch to a MacBook Pro OS-X. While I knew there was a dearth of GIS software for the Mac, I knew all the other reasons for a switch made good sense for me. I continue to use my PC only for GIS needs and every time I use it I hate to boot up the system at all. I have been searching for an easy, inexpensive GIS system to use on my Mac and have been continually disappointed – until now.
First, let me give a quick overview of what I have found… (a more comprehensive review of these systems is on cartographica.com). The tools I’ve downloaded so far are Quantum GIS (QGIS), UDig, SimpleDEMViewer, and OpenOX-Grass. The biggest disappointment is none of the really easy ones have any ANALYSIS capability — I personally don’t think it is a GIS if you can’t analyze the data. Viewing the data is great, but I definitely need more. Also, let me admit I am not sophisticated enough of a Mac user yet to do everything required to run OpenOX-Grass (it requires Apple X11) but I will try to work toward this because it does look very powerful http://openosx.com/grass/grass.html and the price (~$60 US) is right. Also, QGIS with Grass support looks very promising (if I can figure out how to implement it). My conclusion with these existing programs is that those that are easy enough to plug-and-play lack basic analysis capabilities, and those that show promise for being very powerful are limited by not being plug-and-play.
This brings me to a review of My World GIS (v4.1.1) for the Mac (it can also run on a PC). So far I have been pleasantly surprised.
My World GIS
Northwestern University has developed a GIS called My World, which engages ESRI’s MapObjects Java technology. My World is distributed by Pasco Scientific (http://www.pasco.com/myworld/). Built in Java, My World runs on Macintosh OSX and Windows environments. It provides a robust subset of capabilities from a professional GIS environment, including multiple projections, table and map view, hyperlinks, and a common language approach to conducting analyses. It is marketed to educators, but licensing is also available for non-educational use (for research or other non-educational uses) directly from Northwestern University (currently priced at $99 US per single license). There is a fully functional 45-day trial period available.
Data File Types
My World supports the following types of data files and/or folders for reading and writing shape data:
* ESRI Shapefile, Comma-Separated Values, Tab-Separated Values, and GPX Waypoint Files; plus a variety of Grid and Image file types, and WMS data feeds (more info here).
Adding Your Own Data
I did find adding my own shape files a bit confusing at first since My World doesn’t support the shape files in their native projection and requires them to be un-projected. That this wasn’t totally straight-forward was my only real disappointment with My World. But once I got past the hassle involved with importing my own data, I had a lot of fun with this program.
“My World accepts shape data only in Unprojected Latitude and Longitude in Decimal Degrees, and the longitude must be in the range -180 to +180 (rather than 0 to 360).
If your data uses another projection or different units, you can use My World to un-project and convert it to the proper units by selecting Un-Project Shapefile… from the File menu, or by clicking the Import Data From File… button in Construct mode.
My World accepts projected grid and image data, but you must know all the details of the projection used to project that data before you can use it in My World.”
How I added my own shape files… (some data does come pre-packaged)
I had to really experiment with this before being able to import my shape files and have them show correctly on the map. I was successful using the following steps:
1. I copied my existing data into a temporary folder before using the “Un-project” function (and DEFINITELY HAD A BACKUP OF MY ORIGINAL DATA ON AN EXTERNAL DRIVE).
2. I also created a new folder in the Data directory (in the My World application folder) to hold my data after I un-projected it.
3. When I used the “Un-Project” function, I saved the new files into the new directory folder (I got errors every time I just replaced the existing files).
4. I then deleted the temporary folder containing copies of my original data (My World gets confused if it finds 2 datasets with the same name).
5. Under the “Construct” tab, I added my data to the map by simply dragging and dropping the layer from the Library to the Layer list.
6. You can set the map projection later.
Now the fun part – seeing what My World can do.
Note, under the Visualize and Edit tabs, single click a layer to make it active and double click the layer to set parameters or edit.
I am pleasantly surprised by the cartographic capabilities of My World. You can outline and fill polygons with any standard or custom RGB value, easy create color ramps, categorize data, create dot density maps, transparencies, etc. If you’re familiar with commercial GIS platforms it should be pretty intuitive (and maybe even easier). There are about 20 shapes for point symbols, all of which you can control the size, color and transparency.
In My World you don’t label features per se, you create annotations. This wasn’t intuitive and was kind of buried in the documentation (especially since I was expecting labeling to be done in the same place as symbology), but it was really easy to do once I figured it out. Under the Edit tab, you have to click create new layer. One option you will be presented with for the new layer type is “Annotation.” You can then create an annotation layer from an existing layer, select the existing database field for the annotation, choose from a wide array for fonts, colors, sizes, style, alignment etc. While you can’t do a halo, you can do a background block color and make it transparent to help your text stand out. And since it is annotation, you can just select and move your text around to improve placement. Pretty sweet.
This is by far my favorite part.
Not only is it robust, but the analysis menu is also super easy to use. Again, if you know GIS and how to do analysis it should be pretty intuitive. Otherwise, there is pretty good documentation available. For example, I was able to very easily “select by spatial relationship” all the building features (first layer) that were within 15 feet of all commercial properties (second layer)(see example). You have the option to save this as a new layer, or make it a selected subset of the existing layer. All the analysis capabilities for selecting by value, by comparing values, by spatial relationship; combining by intersect, union, subtract, and clip; adding fields by math operation, by copying values, reclassifying, computing distances, and selecting members; creating charts of the data, buffering data; dissolving, summarizing statistics, and converting data are all in one place, intuitive and easy to use, and come with a menu complete with graphic depiction of the operation. Wow.
From the edit tab, you can create new layers and/or edit the geometry and data for any of your existing layers, including grids. I easily moved vertices and created new polygons. A note of caution, it seems to automatically save your changes, but there is an undo button or ctrl-Z.
Overall, the data were pretty zippy to load large files and Web Map Services (WMS). While this wont replace your enterprise GIS, it is a fine system for stand-alone GIS use on your Mac. Besides my own use, my kid’s school only has a Mac computer lab and I now have a good option for getting GIS into their curriculum. I personally am thrilled to have a functional GIS option for my Mac.
My World GIS – I put in the category of “robust low-cost GIS; professionals will be surprised.”