Thursday, March 19, 2015

Flow Line Mapping: Fighting with Corel Draw

This week's torment, I mean assignment:

Complete a map of Immigration to the United States.

The specific objectives included:
- Assess design issues for flow line mapping
- Calculate proportional line widths using excel
- Construct flow line map using proper design techniques
- Apply style and visual effects in CorelDRAW

The new skill I learned: Flow Lines
The headache I had: Corel Draw

To be fair, there is certainly a case to be made for using Corel Draw instead of ArcMap. For instance, when it comes to making a Flow Map, Corel Draw is a better choice, so I am told. Also, if you want your Flow Lines to have proportional thickness, then Corel is a better choice.  I did learn a great deal this week using Corel Draw, however, I have to believe there is a tool in ArcMap that will allow us to make Flow Maps.  In fact, there were a few blogs that discussed this very fact:

I reviewed all the above and even downloaded the Flow Line Tool, but did not use it for this Lab (honest).

The computation to make proportional Flow Lines was straight forward enough, though on the quiz, the correct answer did not appear to be one of my choices...I couldn't have done the math wrong (maybe)? The formula goes like this:

Width of line symbol = (maximum line width) x (SQRT value / SQRT maximum value)

Where SQRT is, Square Root. This was the easy part; computing what width each Flow Line from the various Regions (Africa, Asia, Europe, North America, Oceania, South America and Unknown) would be.  The challenge for me was using the Bezier Tool on Corel Draw.  I cannot tell you how much fun I had trying to get those curves looking like curves. Nope, I really can't say. Nonetheless, I persevered and had extra practice when my entire map was locked-up and then disappeared from Corel Draw--did that happen to you too?.  Did I mention Corel Draw is not my favorite GIS Tool?  

In the end, I completed a map with multiple legends, including a choropleth legend; added a bevel and transparency to my Flow Lines; and I used Posterize on my map, because I could.  I am happy to say, I now know what Flow Lines are, and how to make them using Corel Draw.

No comments:

Post a Comment