topic Re: ArcMAP Symbology in Forestry Questions

ArcMAP Symbology

RyanPinguely — Mon, 29 May 2017 19:55:54 GMT

Hello,

This is an ArcMAP 10.4.1 question. Is it possible to symbolize using one value field; then color and size that symbol using another field? I am trying to display a set of surface geochem data. I would like to choose a different symbol for each rock type then color and size that symbol depending on its gold value. So far I am able to symbolize each rock type differently and size each symbol according to its gold value, but I am not able to choose different colors for the increasing gold values. I am using the multiple attributes function in symbology.

Thanks

Ryan

Re: ArcMAP Symbology

AbdullahAnter — Mon, 29 May 2017 20:19:15 GMT

What is your layer geometry type ? ( point or polygon?)

Re: ArcMAP Symbology

RyanPinguely — Mon, 29 May 2017 20:22:03 GMT

Point

Re: ArcMAP Symbology

JoshuaBixby — Mon, 29 May 2017 20:22:05 GMT

Have you tried Drawing features to show quantity by category—Help | ArcGIS Desktop ? If so, what did you try, specifically, and what results were you getting relative to expecting?

Re: ArcMAP Symbology

RyanPinguely — Mon, 29 May 2017 20:28:42 GMT

Yes, I did try using the categories section but that section does not include the symbol size feature like the multiple attributes section does.

Re: ArcMAP Symbology

XanderBakker — Tue, 30 May 2017 02:55:25 GMT

To bad that you are not using ArcGIS Pro. In ArcGIS Pro this is standard functionality: using 1 attribute for size and the second for color...

... and also ArcGIS Online (ArcGIS Mapping Made Easy) does support this:

Re: ArcMAP Symbology

XanderBakker — Tue, 30 May 2017 03:22:49 GMT

OK, so maybe it is possible without too much manual stuff in ArcMap.

If both your attributes are continuous values, you could create a new field and fill that with the classification of the field you want to use to define the colors. In my example below this would be the field "ClassAttr1". Select the "Quantity by category" option in "Multiple Attributes", select the ClassAttr1 field as the only Value field and select the appropriate color ramp... and add all values

Next select the Symbol Size button and select the other attribute that contains the values for the size of the symbol:

Hit OK twice and you will get symbols colored by one attribute and sized defined by the second attribute:

Re: ArcMAP Symbology

RyanPinguely — Tue, 30 May 2017 12:05:12 GMT

Thanks Xander,

Using this approach would definitely display the data enough to get my point across, but can you think of a way to use different symbols for the values of "ClassAttr1", then have the color (blue low values to red high values) and size increase according to "Myattribute2". I tried changing the colors in the symbol size feature to no avail. I think displaying the data how I have described would get my point across pretty nicely.

Thanks again,

Ryan

Re: ArcMAP Symbology

XanderBakker — Tue, 30 May 2017 12:53:45 GMT

If I understand this correctly, You would be using the same attribute for both color and size. To do this, you would still need an additional field that contains the classification of that attribute and use that field for displaying the colors with a ramp that has colors fading from blue to red and use the original values to define the size. Is that what you are after? Is it possible to share a sample of your data to have a look if that works?

Re: ArcMAP Symbology

RyanPinguely — Tue, 30 May 2017 13:18:47 GMT

The images above show my current setup in symbology and how they are being displayed. I basically just need all the different symbols to change color with increasing values like I have shown in the symbol size window. So, I accomplished two out of the three goals. 1. Give different symbols for each rock type. 2. show increasing size symbols for higher values. 3. have different colors for increasing values. FAILED.

The third goal was not accomplished. Unfortunately, I am not able to share any of this data. But any assistance would be appreciated.

Thanks

Re: ArcMAP Symbology

XanderBakker — Tue, 30 May 2017 14:29:52 GMT

Once I resolve some issues I'm experiencing with my license server I will mimic some data and see how far I get.

Re: ArcMAP Symbology

XanderBakker — Tue, 30 May 2017 16:01:06 GMT

OK, so I think it will be possible, but it will require some manual configuration:

I generated a random dataset with this structure:

The SoilValueClass is a classification of the SoilValues into 5 classes.

I used two field as Value fields (Soil and SoilValueClass):

I manually assigned the colors, since applying the ramp will assign blue to "igneous, 1" and red to the end "Soil, 5" which is not what you want. So I selected "igneous, 1", "metamorphic,1", etc up to "soil, 1" and assigned the blue color and for every "SoilValueClass" value a different color in the range of blue to red.

The Symbol Size was defined by the field SoilValues:

The legend is very, very, very long...

Re: ArcMAP Symbology

RyanPinguely — Tue, 30 May 2017 16:16:30 GMT

Nice work, how did you populate the "soilvalueclass" field? Is it possible to add a field and populate it in Arc or do I need to do that in an excel file?

Re: ArcMAP Symbology

XanderBakker — Tue, 30 May 2017 16:50:50 GMT

You can use the FieldCalculator (Making simple field calculations—Help | ArcGIS for Desktop ) to fill the new classified field:

In this example I am classifying the Field "!SoilValues!" into 5 classes and my maximum value is 100:

( !SoilValues! - 1) // (100 / 5) + 1

Please note that "Python" is selected as Parser.

If you can share the range of values you have, I can adapt the formula for you.

Re: ArcMAP Symbology

RyanPinguely — Tue, 30 May 2017 16:56:34 GMT

That would be great. The ranges I am using are visible in the image I posted earlier.

Thank you very much

Re: ArcMAP Symbology

XanderBakker — Fri, 10 Dec 2021 22:59:55 GMT

In case you are referring to these "Quantile" ranges:

... it would require a slightly different approach.

You could do this:

Select Python as Parser, activate the option "Show Codeblock"

Past the code below in the "Pre-Logic Script Code":

def Clfy(value):
    try:
        if value == 0:
            return 0
        elif value <= 14:
            return 1
        elif value <= 92:
            return 2
        else:
            return 3
    except:
        return -1‍‍‍‍‍‍‍‍‍‍‍‍

and enter the expression:

Clfy( !SoilValues! )

... where "SoilValues" should be replaced by the name of your field with unclassified values.

Re: ArcMAP Symbology

RyanPinguely — Tue, 30 May 2017 17:36:51 GMT

Well, congrats, you're hired!

Thank you very much for your persistence and ArcMAP skills. Your help has been greatly appreciated.

Have a great day

Re: ArcMAP Symbology

XanderBakker — Tue, 30 May 2017 17:52:17 GMT

You're welcome! Could you mark the post that answered your question as the "Correct Answer"?