proportional symbols not showing full range

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12-07-2017 12:14 PM
NigelBardoe
New Contributor II

Hi all,

I have some data with numbers between 1 and 47.  I want to use proportional circles to show the sizes, and if you look at the circles, they do seem to be showing the data correctly.  However the auto generated legend only goes up to 10.  Also, if I choose to show more than 5 levels in the legend it doesn't do it, but will do it if I try to show 4 or less though still maxing out at a value of 10.    If I choose graduated levels, it correctly recognises that the max value is 47, so I don'y know why it is having issues with the proportional symbols.

Attached is a picture of the symbols and legend, as well as the attribute table field being shown.

There is no normalization.

Units are "Unknown unit"

10 Replies
DanPatterson_Retired
MVP Emeritus

arc* tries to be helpful by selecting a classification method... sometimes it is good, sometimes it is not so good.

Choose you proportional symbol, but specify the classification scheme you want and don't rely on software to make the choices for you

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NigelBardoe
New Contributor II

I can't choose my own classification scheme with proportional symbols, only graduated ones, and I'd rather not use graduated symbols if I can help it.

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DanPatterson_Retired
MVP Emeritus

Yes, the Proportional symbols has its limitations, the sections on number of classes and 'unknown units' have to be taken into consideration

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NigelBardoe
New Contributor II

Thanks for the help but I still can't figure out why the legend isn't showing values higher than 10 when the data goes higher.

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DanPatterson_Retired
MVP Emeritus

it looks like it isn't using the raw data at all, but some form of normalized, and the units are unknown, so who knows.  Graduated symbols would be better given the data that is in your column

RebekahZehnder
New Contributor II

Was this ever resolved for you?

I'm having the same issue.  It seems to me that it is a bug.

I have unit set to 'unknown' and maximum size to 'none' because I want the symbol sizes to be relative to the smallest value (per the documentation).  No matter what I change the legend count to, the highest value displayed is always 10, and it never shows more than 5 classes.  The largest data value is 23.  The dot for the point is the size I would expect and is what I want to show in the legend.

My quick solution is going to be to manually build my own legend, but obviously that is less than ideal.  I don't want to use graduated symbols because then I have to have discrete classes - I want to show varying values on a continuous scale.

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NigelBardoe
New Contributor II

Never found a solution,  pretty sure I ended up just making my own graduated symbols. 

DavidHofmann
New Contributor III

I have a work arround, that works for me, but only if the goal is to create a static map:

Just insert a much higher "fake feature". So if the largest value is 23, just  create a feature outside of your map canvas, that has the value 50 or even 100. After this the legend count can really be upt to 12 and the highest value will not be 10.

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MarkSzegner
New Contributor III

Pasted from ESRIs help (credit to Heather Smith, Author at ArcGIS Blog ), this fixed it for me (had the same issue):

"True proportional size
Use this if you want to draw symbols which are truly proportional to one another. For example: City A has a population that is twice as large as City B, so you want Symbol A to draw twice as large as Symbol B. To accomplish this, choose None as the max size. Now your smallest value will draw with your min size. All other symbols will grow proprotionally from there.
Notes:
• Only values greater than zero will draw.
• Often when you choose this option, your symbols will blow up to enormous sizes, sometimes flooding the entire screen. True proportional symbols are not appropriate for all value ranges.
• When I say that one symbol is twice as large as another, I mean its area is twice as large, not its point size, or diameter, or circumference. Specifically, the square root of the data value will be used as the radius to calculate the area of a circle symbol."

https://www.esri.com/arcgis-blog/products/arcgis-pro/mapping/arcgis-pro-size-guide/ 

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