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I need help with "Drawing features to show multiple attributes"

September 27 2007 | 0 comments
Categories: Symbology

Dear ESRI cartographers,

I need help with "Drawing features to show multiple attributes". I can not get the map that has polygons shown with graduated color (one attribute) and graduated symbols (second attribute)at the same time. Help System provides step-by-step insructions but step 8 is vague (see attached DOC file - copied form the Help system). I know how to do it if there are two copies of the same layer in the TOC, but I want to know how to do it with one copy.

So, could you please test these instructions with any of your datasets and elaborate more on Step 8?

Thank you very much!

Attachment: From ESRI Help System

Mapping Center Answer:

The user interface for this is ambiguous. You can only set values, and then click either the Color Ramp or the Symbol Size button; whichever you click last will be what is saved.

Thus, the short answer is that show Multiple Attributes option for Quantity by Category cannot do Quantity by Quantity, which is what I think you are asking for when you say you want “graduated color (one attribute) and graduated symbols (second attribute).

It is a little easier to work around this limitation in 9.2 using representations. The idea is that you will need have your graduated color attribute be represented as categories instead of quantities. That probably means adding another field to your data that indicates which class your features belong to. The easy way to do that is to symbolize the layer by graduated color and then create representations. The rule_ID field is effectively a surrogate for each class, so use it for your value field. Then set the Symbol sizes using the second attribute.

One other thing to note is that if you want to use the same color ramp, save it before you create representations. The reason you have to save it is that the saved copy will not have it’s category set to anything, which means it will be shown in the unique values user interfaces (in the ESRI style, the color ramps are divided into categories for color schemes and color ramps; the schemes for balanced random colors, and the ramps to indicate progressions of values).

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