Select to view content in your preferred language

200 unique value limit for symbology in ArcGIS Online?

6314
7
03-26-2015 06:13 PM
AllenRisley
Occasional Contributor II

I am working with a student who would like to create a map using ArcGIS Online that shows the number of members of an organization in the various countries of the world.  My plan was to give the student a zipped shapefile of the World Countries Generalized map layer, with extra fields added for them to enter their data.

I made the shapefile, zipped it and uploaded it to a map on ArcGIS Online to test it out.  When I loaded the shapefile and was prompted to Change Style, I tried to use Types (Unique Symbols) to assign different random colors to the countries.  About ten countries were assigned colors and the rest were put in the Other category.  I have worked with this in the past and scrolled down to Other to click on the double arrow in order to "Move values out".  Unfortunately, once it hit 200 countries in the symbology list it stopped.  There is a message that says: "There are more than 200 unique values.  Values not listed here will still display on the map in this category".  I guess this means that I have to decide which countries are going to be shaded grey as "Other"?  Or is there a work-around to this?

Thanks,

Allen Risley

GIS Specialist

California State University San Marcos

7 Replies
DanPatterson_Retired
MVP Emeritus

that is way too many categories and no one will be able to differentiate the colors etc.  You would be best to devise a scheme using ranges of values and symbolize accordingly

0 Kudos
AllenRisley
Occasional Contributor II

The intent is not to use the colors to identify the countries from a legend.  The intent is to color the countries somewhat randomly, so that bordering counties are clearly seen as being separate.

What I would like to be able to do is simply have random colors applied to the countries, similar to this map.  http://cdn.shopify.com/s/files/1/0071/5032/products/World_Maps_International_20mil_1.jpg?v=141361911...

Here's the Feature Service I'm working with: http://csusm-gis-lab.maps.arcgis.com/home/item.html?id=01c4d9bf9c7a4ad79ec7bd7afa0c2316

How would you symbolize this in ArcGIS Online, so that contiguous countries have recognizably different colors, given the attribute fields that are available?  It's done quite easily in ArcMap.

BAXTERQ_ANDREWS
New Contributor III

I would uses ranges for the values too show where the most of the organization live. I would also be interested in the characteristics are of those members: age; gender; active/inactive member; etc. After you know where the most of your membership is, you will then want to eventually breakdown the characters of the members as to increase member and utilize recruiting skills to adapt to your collected characteristics.

AllenRisley
Occasional Contributor II

Sorry - my original post was a bit confusing.  We understand how to symbolize the layer once the membership data was entered - not a problem there.  But as I was going through the steps of the task I ran up against something that I saw as a problem with the ArcGIS Online symbology.  When I loaded the World Countries layer I expected it would allow me to assign random colors to all the countries in the layer (254 of them).  But once you reach 200 it stops, unlike ArcMap on the desktop.

Ebrahim
New Contributor II

This is not user-friendly. Imagine wanting to add 50 legend items a couple of times to check for improvements and having to wait each time that they'd go away "eventually."
Not only do I not get an option for bulk importing my perfectly named icons for a feature layer, but also, I hit the "Maximum number of symbols reached." and have to wait for them to decide when I can continue. Just Ridiculous. Bad practices are prevalent in ESRI everywhere. Very lousy programming in the UI of the final products for designers and developers. 

0 Kudos
RandyMcGregor3
Occasional Contributor III

For a series chart, for example, you will never show more than, say five values, but if the dataset has more than a certain number, no unique colors are provided, no matter how many you have selected to chart. No one wants 100 unique colors to be displayed at one time, but when you have hundreds of unique values and you cannot depict the smaller number you have selected with individual colors, that is unfortunate.

What would be handy would be if colors were applied after the selection is made, so that the renderer only needs to provide colors for a small number of unique values at a time.

We have large datasets that represent data from multiple sites and cannot get unique values to show, even for sites that have a small number of values. It would helpful if dashboards could just pick a certain number of colors and randomly apply them even when there is a large number of unique values.

0 Kudos
ar_taswater
New Contributor II

I'm struggling with this from the other side - trying to fix unique value symbology that has been assigned across hundreds of unique values. Not only is this a bad idea visually, it's also a bad idea in webmaps as I've found it will massively increase the size of the json behind the map.

Ths json behind the webmap will describe every single value/colour multiple times to handle the actual symbolization and then to display it in the legend. This was one of the major issues that was significantly slowing down some of our webmaps.

A better option is to add a colourclass field, and then use https://www.arcgis.com/home/item.html?id=5fa04ce288284c999f70464e1c3b2e82 to apply the four/five colour theorem. You only need four or five colours to ensure different colours to adjacent polygons https://en.wikipedia.org/wiki/Four_color_theorem

0 Kudos