topic Re: Re-size symbology by View Scale in Mapping Questions

Re-size symbology by View Scale

KamillePreto — Thu, 19 Aug 2021 14:51:32 GMT

I am trying to create a custom expression on a feature so that it will re-size the symbology as I zoom in and out. Like this example ESRI Blog - https://www.esri.com/arcgis-blog/products/js-api-arcgis/mapping/how-and-why-to-adjust-size-by-scale-in-web-maps/

However, everything I try, I keep getting errors.

I've also read this blog as well, but the steps are too complex for what I need to accomplish, as I don't have a layer I need to symbolize by attribute. - https://community.esri.com/t5/arcgis-living-atlas-blog/automatically-resize-symbols-by-map-scale-in/ba-p/887307

This is where I left off, basing off of the blogs:

I just have a simple layer for Manhole locations.

This layer is a part of a Web Application for our Asset Management database (bridges, dams, outfalls, signals, inlets, pavement, etc). So there will be a lot of layers involved. I made a custom symbol for the Manholes & Inlets, and you cannot see the detail when the symbols are a smaller size.

Can anyone help let me know how to fix my expression? I will need to do this will all of the layers involved.

The scales listed in the expression were from one of the blogs, I did not set them myself.

Thank you!

Re: Re-size symbology by View Scale

jcarlson — Thu, 19 Aug 2021 15:00:51 GMT

You can refer to the When page, but basically you need a default value at the very end for when none of the conditions are met. Just add ", 5" before the final parenthesis.

Re: Re-size symbology by View Scale

KamillePreto — Thu, 19 Aug 2021 15:10:25 GMT

Hi Josh,

Thank you again. My script already has a ", 5" before the final parenthesis, so I added another just to see if it would work, but I am now getting a "Parse Error: Line 8: Unexpected identifier".

var vs = $view.scale

when(
vs >=37000000, 30,
vs >=18500000, 20,
vs >=9300000, 10,
vs >=4700000, 8
vs >=2000000, 5, 5)

Re: Re-size symbology by View Scale

jcarlson — Thu, 19 Aug 2021 15:14:59 GMT

Now you're missing a comma after the 8.

Re: Re-size symbology by View Scale

KamillePreto — Thu, 19 Aug 2021 15:31:22 GMT

Thanks for catching that. Fixed and updated to the script below.

var vs = $view.scale

when(
vs >=5000, 8,
vs >=2300, 15,
vs >=1200, 20,
vs >=600, 25, 5)

However, now this is what I'm getting -

But I don't believe it worked correctly. The symbols get smaller when I zoom in, and I wanted them to get larger. I also don't know what the legend is counting (>40, 30, 20, 10, etc). I still think I'm doing something wrong. Am I typing in the view scale incorrectly? I'm just super confused.

Re: Re-size symbology by View Scale

jcarlson — Thu, 19 Aug 2021 15:51:09 GMT

So, those numbers you're defining with your expression are just arbitrary values, they're not directly setting the symbol size number. What you'll need to do is to open the symbology settings to adjust the min/max values, as well as the min/max symbol sizes to match the min/max values from your expression.

Re: Re-size symbology by View Scale

KamillePreto — Thu, 19 Aug 2021 15:54:28 GMT

Where do you see this option in Symbology settings? I don't have that.

Re: Re-size symbology by View Scale

jcarlson — Thu, 19 Aug 2021 16:11:20 GMT

Click the "Options" button.

Re: Re-size symbology by View Scale

KamillePreto — Thu, 19 Aug 2021 17:08:32 GMT

I'm sorry, maybe my last question wasn't clear. I don't have the "View Scale Based" symbology options where you can customize a min/max. I only have the normal symbology options - choosing a symbol, transparency and visible range.

Re: Re-size symbology by View Scale

jcarlson — Thu, 19 Aug 2021 17:30:44 GMT

On your own screenshot, you have circled the options button.

"View Scale Based" is simply what I titled my expression.

Re: Re-size symbology by View Scale

KamillePreto — Thu, 19 Aug 2021 18:17:17 GMT

Hi Josh,

Yes, I am very familiar with the Options button. When I selected it the first time, that sliding bar with the min/max was not there. Now after re-entering the expression again, it is. But I still do not think it is correct. When I zoom in the points get smaller. When I zoom out, they get larger. I wanted that flipped. So I went back into the expression and switched the numbers from top to bottom and it is still doing the same thing. So I changed the slider (min/max) and that does work. But I just don't understand what the legend is referring to. What are the numbers? - If they are the second numbers in my expression (25, 20, 15, 8), those were just random symbol sizes I assigned to the zoom levels. Not attributes.

Re: Re-size symbology by View Scale

Jim_Herries_UOdocent — Tue, 09 Nov 2021 06:55:56 GMT

Check out this blog. https://www.esri.com/arcgis-blog/products/arcgis-living-atlas/mapping/updated-arcade-scaling-symbology/ to see how one approach works to give your explicit size control by scale.