Methodology and Operational Problems
I had far more operational problems than I expected. The largest problem had to do with querying the database. When the Query Builder was called up, it would not list the possible values for any given field, and would not allow the option of updating the values. I originally didn't consider this much of a problem--I would simply use the meta-data to find out how many different values there were for a field. Then I tried to specify Time as the cost field in Network Analyst. Not only was Time not an option in the drop down menu, but there was also no way to specify it manually. I tried numerous procedures to fix this problem--I made new themes, indexed them, looked at the DBF file in Excel (I noticed that the DBF file I was using didn't have an ID field, which all the new themes I made had. I added an ID field, but this didn't fix the problem). Nothing I tried would fix the problem. Then I remembered that when Greg Zemrau was working on his project, which also used the SNF files, his query builder appeared to be working fine. It took me a while to figure out what the difference between his coverage and mine was, but eventually I realized that he had used the Clip function in the Geoprocessing extension. I made a polygon theme and clipped the street theme with it. The process took nearly and hour to complete, and when it was done, Query Builder still didn't work. I then tried clipping it with a smaller polygon. This time, the new theme worked properly with Query Builder. I then clipped out the portion of the street theme between White Rock and SFU. The problem with query builder probably had something to do with the size of the street theme, but with the amount of time it takes to clip a theme, I didn't bother to experiment further.
'Another problem that I was having was updating the length of the arcs in my Street theme. I address the particulars of this problem earlier in this report.
A "segmentation violation" destroyed most of my work Friday morning. I'm not sure what a "sementation violation" is, but I can say I don't like it's timing.
I originally intended to export the Layouts as Adobe Illustrator files into Freehand 8.0, and then export them from Freehand to my web page as a Shockwave Flash file, which allows them to be veiwed as a vector image instead of a raster image. Unfortunately, Esri's idea of what the Adobe Illustrator file format is and Macromedia's idea of what the Adobe Illustrator file format is are two completely different things. The imported Layout caused enough "Unknown Command" errors in Freehand to crash the computer. I tried to find a work around for this (the exported file wouldn't open in Corel Draw either), but was unsuccessful.
I had briefly considered adding ortho-photos that are available at the library to my project, but I quickly realized that the digitizing of the Street Network File streets was so sloppy that there is no way the streets of the SNF would line up with the streets of the ortho-photo without some major editing.
I briefly had a problem with ArcView crashing. If I selected all of the features in a table while I was editing, ArcView would freeze, and I would have to go to the task manager in order to close it. I did lose quite a bit of work before I learned not to do this anymore.
There was some difficulty getting the Avenue script calcapl.ave to work. It is very picky in what you are allowed to click on or do before you run the script. If the view that you want to calculate distance in is not active, is still drawing, or you just looked at something else, the script will give you an error message. I almost gave up on the script before I figured this out.
Overall, the problems that I had often made me feel like I needed more serious help than the text book (made it through the first seven chapters of next semesters text) and manuals had to offer.