I'm working in ArcGIS 10.

I have a layer that contains 8 attributes and each one of these fields can be categorized into 3 sub categories. I need to display them on a single map.


I tried to add the same layer multiple times (8) and then symbolized each category. when I display the results are good but symbols now superimpose on one another, and hence the categories cannot be differentiated.

The following is an image that contains a sample of what I am working on. "Area" corresponds to the point referring the region and 1A,1B and 1C are the fields of each feature. Each one of them (1A,1B,1C...,1H) is further categorized into 3 categories as shown in the table.

I have added same file multiple times to get all the variables displayed on a single map, which are being displayed as well but they tend to super impose over one another. I want all the symbols to be shown separately.

enter image description here

Can anyone provide any ideas on how to do this?

  • 1
    If you have graphic talent (or not) a hand drawn image of what you want would help us help you
    – Brad Nesom
    Nov 29 '13 at 17:37
  • 2
    An update to the question containing (a clarified) version of the various comments would be a good idea.
    – BradHards
    Dec 1 '13 at 21:01
  • 2
    @Ade'l I don't understand why you are not Using Unique values, many fields on just one layer. Is that giving you some problem? If so what? Dec 2 '13 at 8:14
  • 2
    @Ade'l: Your latest edit made it clear that you have 8 fields, each of which can be categorized into 3; The way to solve this, is to add one more field, and then use Field Calculator to set this field to the concatenation of all the 8 fields. You can then use this field for applying a unique value renderer. You don't need multiple layers, Just one Layer. Dec 3 '13 at 15:28
  • 2

I understand that you want to render a layer which has 8 fields, and each field can be categorized into 3 sub-categories.

My first reaction to that would be: Are you sure? You have a maximum number of 3^8 ==6561 possible combinations of these sub categories.

Much research has been done on how many colors can be distinguished by most people in a map, and the General consensus is that:

  • If you have various shades of one color, most people can't distinguish more than 7 classes.
  • If you are using different colors, something like 11 is the most number of classes people can recognize.

It is true, that the above are just rules of thumb, and you could get away with more classes, there is almost no way anyone could recognize 6561 classes in one map.

So you need to really think, whether you need to display all the 8 fields in one map. Maybe you could make multiple maps.

However if you still feel that you need to do this, I would go about it, in the following way:

  1. Add one more field, and then use Field Calculator to set this field to the concatenation of all the 8 fields
  2. Once the values have been populated in the new field, you can assign a symbol to each unique value of a new field.
  • I appreciate your answer which partially solves my problem. As I have 8 categories on a map and each one of them is divided into 3 sub categories, I am suppose to have a total of 8*3=24 symbols on a map. Te idea of concatination is good but it does not solve my problem...! In the beginning I thought I am done but when I tried it, no man its still far away.
    – Ade'l
    Dec 4 '13 at 12:37
  • since I have a number of violations fall in these categories with a color variation of (reg,green and yellow) ill display them all and trust me this would b readable by everyone.
    – Ade'l
    Dec 4 '13 at 12:43
  • @Ade'l It won't be 24. If each of the 8 field can have one of the three values, there are 3*3*3...8 times. This gives 3^8, which is 6561. Dec 4 '13 at 13:51
  • Its simple as 8*3=24 why would u make it complicated... the image gives u 3 categories and 9 variables only... your procedure for concatenation would make it 6561 variables which is not required as I need only 24 variables on the map. For the same reason I need some other way-out to this.
    – Ade'l
    Dec 6 '13 at 11:31

You could set an offset for each category. And basically build a new symbol depicting multiple categories. Each layer would be assigned a different sector of the symbol and offset in that direction.
Creating a cluster of symbols.

  • These are around 100 categories n 300 variables, to b used in different maps... Re-manipulation will take ages...
    – Ade'l
    Nov 30 '13 at 21:25

Unless I have misread something along the way I believe it could be accomplished by the following three steps:

  1. Add your layer 8 times for each of your category Block No. (243,..., 42)

  2. Add a definition query limiting each layer to one of the 8 category Block No's. (BlockNo = '243'

  3. Then symbolize each separate layer using the Unique Values, many fields functionality for your 3 other variables.

If you need more complexity then that, then you likely need to break it into more than one map. Otherwise, it will be overly cluttered and confusing for your audience, (No matter how savvy they are at reading maps). Personally, as I read your request it sounded like it may already crossed into that category of map. Maps work best when they are simple two or three feature affairs. Devdatta is correct about what the average human can distinguish which must be considered when you create any map.

  • thank you for your suggestion. BUt this is what I have done and what I rec. as a result is basically a problem... yes, when I add same layer 8 times, and give them symols, they tend to superimpose!!
    – Ade'l
    Dec 19 '13 at 10:14

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