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Leader lines for only some point data

February 21 2008 | 1 comment
Categories: Labeling, Maplex

I have a number of point data (aboriginal communities), some of which are crowded together (therefore needing leader lines for their labels) and others where leader lines are not necessary. I can't seem to set an offset or leader tolerance which gives the desired result: leader lines where the concentration of symbols requires them, and none where there is room for the label. The offset at the moment is 5 points, with a 700% maximum. The leader tolerance is set to 0.000. I've tried a few different values with worse results. The attachment shows the "best" solution so far, but it's still not what I want.

As a cartographer who is in the process of switching from MicroStation to ArcMap, I'd like to be able to get ArcMap to do what I would have manually done in CAD.

Mapping Center Answer:

First, definitely change your offset parameters. The offset of 5 means all labels will be offset by at least 5.0 points and never any closer which definitely leaves them hanging in space and not associating well with the point symbols. I would suggest using 1.5 points and 3500% given the sizes of symbols and labels your example showed.

I tried this with both Simple Line Callouts and Line callouts, so I'll give you both:

Simple line callouts: Leader tolerance: 6.0 pts. and I left the Automatically snap the leader to the text option checked. Personally, I didn't like this solution on the data I tried as several leadered labels cut in front of unleadered labels.

Line Callout:

Gap: 2.000
Leader Tolerance: 6.0
Turned off the Accent Bar and Border options
Set all margins to 1.0

This got me a better looking result:

1. No leaders for labels that did not need them.
2. Fewer leaders crossing each other.
3. Fewer leaders crossing over my points symbols (feature weights do not affect leader placement).

My rule of thumb for setting the leader tolerance is half my text size + my gap (so in my test I had 8.0 pt. text and a gap of 2, so 4 + 2 = 6.

Close! posted by Tony Veale on Feb 21 2008 6:22PM
Thanks for your answer. I've tried it, and it's close to what I was hoping for. There are still some slightly weird positioning of leader lines, but in my limited experience, I expect that from Maplex. Short of now converting the labels to annotation (which I don't want to do if I can help it), and moving a few of them, this seems to be the best way forward.
Thanks for your extremely prompt reply (especially given the time difference!).

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