Wednesday, February 28, 2007
Wednesday, February 14, 2007
There's the map of counties in the United States which lost population in the period from 1990 to 2000, and who also had more male than female residents. We studied queries in this chapter and it was really getting into the analysis power of GIS. It was interesting, and I was impressed at all the possibilities for analyzing spatial data with SQL statements. Mary didn't find it so interesting, but maybe if she were working on a more real life scenario, she would like it better. I also determined that Mary did not contribute to the lost population trend seen in the map to the right. All the talk about queries reminded me of a fellow student in a previous database class who pronounced that word more like "quiries" with a long "I" sound in the first part of the word.
Since it was valentines day, it was a special day at GIS class. There was an air of electricity and anticipation as we all worked on our projects. The boys and girls exchanged long looks and sideways glances. Some couldn't help themselves and burst into singing romantic songs.
It was also a special day because it was on this day in 1989 that the first GIS satellite was launched. That doesn't seem that long ago when I think about the fact that I have a GPS in my car and almost take it for granted as a navigation aid. I also remember the time of the launch and thinking that GPS sounded so exotic that regular people like me would probably never get to use it.
Saturday, February 10, 2007
Wednesday, February 7, 2007
We had our first test tonight. I thought it was a very fair assessment of the material we had covered. I know I got some things wrong, I hope not too many.
Tonight we worked with tables. It was a lot of fun. Well, not really. It took me back to database classes I had in the past, and was a good refresher on db concepts and how ArcGIS uses tables. The exercises got intense with linking and relating tables, and talk of cardinality. I remember those relationships in MS Access and how they could get pretty messed up. Good thing relationships in real life don't get messed up like that. But then, in computer databases you can usually click yourself around and straighten things out. I made this map, which didn't export very nicely, about how many federal elected officials each state has. Later we did some more advanced data manipulation in the tables that was impressive, but yielded no spatial data output vectors to sho on here.