Happy #MapInfoMonday, from my chair it's a wonderful sunny day,
Today's article is a bit different from the earlier articles. I thought I would try to get you involved a bit more by discussing some options. As you probably know, most things in MapInfo Pro can be done in a number of ways. Some ways tend to be a bit better than other ways, however.
Let's have a look at visualizing the population on a map. How would you do this? Let me give you a couple of ways and hopefully, you will help me pick the better option, or even suggest an alternative.
Ranged Thematic with Counts
The first suggestion is the use the standard Ranged Thematic and colorize the polygons based on the number of inhabitants.
This is easily done. From the
Add Theme control, you pick the thematic type, a template and then you select the table and column to use.
The Thematic Map clearly shows the areas with a higher population in darker colors.
Ranged Thematic with Density
The second suggestion is also using a Ranged Thematic but instead of using the population count directly, I will divide it by the area of the polygons to get a population per area unit, in my case square kilometers.
The process is similar to the above but instead of selecting a column, I use the
Expression... option to calculate the value for my thematic map. Below you can see the expression I used. Noticed that I used the
CartesianArea
calculation as my data are using a projected coordinate system. If you are using Longitude/Latitude data, use
Area
instead.
The resulting map is quite different from the previous one as it now takes the size of the polygons into account as well.
Dot Density
The third and final option that I wanted to give you today, is the Dot Density Map.
Dot Density is a different thematic type. It allows you to assign a value to each point rendered in each polygon. In this way, each point will represent a number of inhabitants, as an example. In the example below, you can see that I assigned the value 1,000 to each point.
You can assign a different color but black to your points too if you prefer a more colorful map.
The Dot Density Map is somewhat similar to the second option I shared with you. This becomes clearer if you have both layers on a map.
Now over to you. Which option would you use? And why? Or maybe you have an alternative?
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Peter Horsbøll Møller
Principal Presales Consultant | Distinguished Engineer
Precisely | Trust in Data
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