Unique values, many fields: many polygons are not symbolizing within categories

Question

Original User: jkraemer In ArcGIS 10 I have a zoning layer of almost 9300 polygons that covers each of eight municipalities in the county. It is symbolized by unique values in these three fields: Municipality, Plan_Area, and Zoning. For each zone type, I have values from each municipality carefully grouped because they tend to use different codes for the same zone meanings (e.g. General Agriculture/Rural group is grouped "AE,Rural,A1; AE, Rural, A1-1;...BR,Brant,A1-10;BR,Brant,A1-11;...HK,Rural,AG-15;HK,Rural,AG-19;...NBP,,RU1-g;NBP,,RU1-i..." etc. This makes for incredibly long value lists of hundreds of entries. I've attached a screenshot of the layer properties so you can get a better idea. While you can only see the first six categories here, there are 74 of them in total. What I am finding is that some of the polygons in these categories are not being drawn on the map, as shown in attached sample.png. One entire municipality at lower left is completely missed, even though it's defined in the symbology and its polygons are "Identify-able" on the map. I am wondering if there is a limit to the number of values permitted per symbol. Maybe I've exceeded it? How can I fix this? I must show the zoning as a single layer. Please help! sample.png layer_properties.png AurelienRobert_1-1750455115723.png AurelienRobert_0-1750454984384.png

RichardFairhurst · Answer

I had not realized the "Count" heading is clickable, but doing so does exactly what Richard said it would. I am now working my way through grouping the list of values it revealed for me. There were hundreds!

Thank you Richard!

Thanks for confiirming that my advice worked.  I believe this is related to issues concerning the fact that ArcGIS 10 does not like to read more than the first 2048 records by default unless it is forced to (similar behavior restictions occur if you do not press the go to last record button in a tableview with more than 2048 records in it).  The Complete List button should force the read of the entire table, so I consider this a bug that it does not.  But at least the Count option forces the full table read.

Anonymous User · Answer

Original User: jkraemer

I had not realized the "Count" heading is clickable, but doing so does exactly what Richard said it would. I am now working my way through grouping the list of values it revealed for me. There were hundreds!

Thank you Richard!

RichardFairhurst · Answer

Thanks James for your reply. I have had no success with this problem. When I do as you suggested with 'Add Values' and 'Complete List' there are no other categories. I believe I tried that before I posted, so no change there.

I am not using any definition queries on this layer.

I have just found another MXD that has the same layer and it appears to be drawing properly there. I just need to verify it's symbolizing exactly the same, but I think I'm set for now. Thanks again.

Prior to attempting to "Add Values" you should first click the "Count" heading in the main Symbology dialog window.  If there are any unsymbolized values they will be counted under the top "all other values" group.  If any value other than 0 appears in that category you have missed some grouping values.  I also find that sometimes after all the records have been read to populate the "Count" values that suddenly "Add Values" will show values in the "Complete List" that it did not show when I used it prior to doing the "Count".  Let us know if this helps.