Ask A Cartographer

RE: Aspect/Slope style

April 02 2010 | 0 comments
Categories: Symbology

Our Answer:

>"You will see in this blog that we used the Classified renderer to show the symbology, then we set each class to a specific color. It sounds like you used the Unique Values renderer and again set a color for each class. When you do this, you do not actually use a color ramp. So saving your symbols to a style will not save a color ramp - instead it will save the colors -- even the ones you modified."

This makes sense, but in the Style Manager one can create a "Preset Color Ramp" and choose individual color swatches for each segment of the ramp. So theoretically, I could imagine that a color ramp could be created using each of the swatches from a Unique Values or Classified renderer.

>"Edits made to a color scheme or a color ramp in ArcMap are not saved in the color ramp drop down menu the next time you open the layer, so the only way you can save those edits is to Export Map Styles."

When I "Export Map Styles", and then examine the results in Style Manager, I only see symbols in the "Fill Symbols" and "Colors" folders. Even though I have layers in the TOC displaying data using the Stretched and Classified renderer - and these are symbolized with "Color Ramps".

>"Edits made to a symbol using Style Manager are automatically saved. So a good rule of thumb when you modify a symbol in ArcMap, whether it is a single color, a color ramp, or any other symbol, is to use the Save to Style option immediately before getting out of the dialog. This way, you can save each modified symbol in your own personal style using a name that you will recognize."

I'm familiar with the "Save to Style" option when editing symbols/labels/colors, however I can't seem to find where I can save a customized "Classified" color ramp. Am I just missing it?

There also doesn't seem to be an option to save and load a customized classification (under Layer Properties) - like I can do in Spatial Analyst/Reclassify. That would be handy...

Mapping Center Answer:

OK -- let's see if this helps. I think there are three things you are asking: 1) how can I set the colors in a preset color ramp to be those that are used in the Unique Values or Classified renderer, 2) why are the color ramps you are using not getting exported, and 3) how can you save a customized color ramp? Let's take these one at a time.

How to set the colors in a preset color ramp to those used in the Unique Values or Classified renderers

Using Style Manager, you can set each color in the preset color ramp. Note however, that this is not the best way to set the colors for the aspect-slope map as there are not enough colors to set and they would not be applied in the correct order. If instead there were only 13 colors in the aspect-slope map and you could create the preset color ramp so that it always assigned the right color to the right category, you could use a preset color ramp. So the bottom line is that you could only use a preset color ramp with a data set the way you are discussing with a 13-category map that you know will always have the same order of categories.

How to export the color ramps in your ArcMap document

The color ramps should be exported when you Export Map Styles. If it is not, you would have to check with Technical Support about what the issue is. However, you can also save a modified color ramp to your personal style, so long as you do not exit the Layer Properties dialog before you save it (see the next paragraph.)

How to create a customized color ramp

You can either do this in the Style Manager by creating a new color ramp or copying an existing one and editing it or you can do it in ArcMap by editing an existing color ramp. If you use Style Manger, right click the space at the right when you have the Color Ramps folder highlighted and click New, then click Algorithmic Color Ramp - or whatever kind of color ramp you want to create. Then right click the new color ramp in the space at the right and click Properties. Alternatively you could do this right in ArcMap. On the Symbology tab, select a color ramp to edit, right click it and click Properties. Here you can make your changes but before you get out of the layer properties, make sure you click the Save button on the Symbology tab to save the edited color ramp to your personal style.

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