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How do I set up a proper legend for total population?

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#1
MaD

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Attached File  tanzanaiapop2.jpg   235.35KB   59 downloads



#2
frax

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Hi, maybe you need to rephrase that question? What software do you have at hand, and what do you mean by 'proper' legend - in contrast to the one you have used now!


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#3
DaveB

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Which category does 70,000 fall into? Or 200,000? Or 400,000?


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#4
Fran├žois Goulet

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Which category does 70,000 fall into? Or 200,000? Or 400,000?

 

Personally, I don't have anything against repeating classes, the chance that the population is exactly 200,000 or 400,000 is thin. But if it was the case, the "convention" I learned is that the lower value is included and the highest excluded. 

 

Another thing is you shouldn't have a population of -999. It probably means no data and it should be removed.

 

Since you only have 1 red circle (Dar es Salaam), it probably means that it's the only value in the class 400,000 - 3,000,000, it's misleading. It could have a class of its own.



#5
l.jegou

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Absolute population numbers should always be represented by proportional symbols (surfaces). You gain nothing by regrouping populations values into classes, instead you lost much information.



#6
David Medeiros

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I disagree with the notion that you should never classify pop values. Class groups aggregate infromation and set up a visual distinction by type of poulated place, as determined by the pop class it falls into.

 

That being said, you should have some system and rational for creating the classes. Small, Medium, and Large cities for instance, based on natural pop breaks or some established threshold for these disticntions.

 

In your case, with so few cities showing, you'd probably want to reduce the number of classes (or go ahead and show proportional symsbols by raw values).

 

I'd also stick to just one symbol variable for this. Use only symbol size rather than size and color.


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