GIS Question of the Day # 6 - Symbol Format

Question:

In ArcGIS, what type of format is used for symbology i.e. png or svg?

Answer:

In ArcGIS, symbology can utilize various formats for icons and symbols, with the most common being PNG and SVG formats. Here’s a brief overview of these formats and their use in ArcGIS:

PNG (Portable Network Graphics)

• Description: A raster graphics file format that supports lossless data compression.

• Usage:

  • Commonly used for icons and symbols in ArcGIS due to its support for transparency and high-quality images.

  • Ideal for complex images with gradients, shadows, and other detailed graphics.

• Pros:

  • High-quality images with support for transparency.

  • Widely supported across different platforms and applications.

• Cons:

  • Larger file sizes compared to vector formats like SVG.

  • Not scalable without losing quality.

SVG (Scalable Vector Graphics)

• Description: A vector graphics format that uses XML to describe two-dimensional graphics.

• Usage:

  • Often used for symbols in ArcGIS due to its scalability and ability to retain quality at any size.

  • Ideal for simple, geometric shapes and icons that need to be resized frequently.

• Pros:

  • Scalable without loss of quality.

  • Typically smaller file sizes compared to raster images.

  • Easily editable and customizable.

• Cons:

  • Can be more complex to create and edit compared to raster images.

  • Not suitable for complex images with detailed textures or gradients.

Choosing Between PNG and SVG

• Use PNG:

  • When you need high-quality, detailed images with transparency.

  • For raster-based symbology where the image complexity is high and does not require frequent resizing.

• Use SVG:

  • When you need scalable icons and symbols that maintain quality at any size.

  • For vector-based symbology where geometric shapes and simple designs are predominant.

Implementation in ArcGIS

• ArcGIS Pro: Supports both PNG and SVG formats for symbols. You can import custom symbols in these formats through the symbology pane.

• ArcGIS Online: Also supports both PNG and SVG for web maps and applications. Custom symbols can be uploaded and used in web maps, dashboards, and other applications.

• Symbology Libraries: ArcGIS provides a range of built-in symbols and icons in both PNG and SVG formats, which can be customized and used directly in your maps and applications.

By selecting the appropriate format based on your needs, you can ensure that your symbology is both high-quality and functional within your ArcGIS projects.

GIS Question of the Day #5 - Symbology

Question:

In ArcGIS, Is Symbology displayed on map/layer using database column or external link or something else?

Answer:

In ArcGIS, symbology is typically determined by the attributes stored in the database columns of your dataset. Here’s how symbology is applied and managed:

Symbology Sources in ArcGIS

1. Database Columns (Attributes):

   • Attribute-Based Symbology: Symbology is often based on the attribute values in your dataset. For example, different colors, sizes, or symbols might be used to represent different categories, ranges, or specific values in an attribute column.

   • Dynamic Updates: Changes in attribute values can dynamically update the symbology if the symbology is set to reflect those values.

2. Symbology Definitions:

   • Styles and Symbols: ArcGIS includes built-in styles and symbol sets that can be applied to layers. These predefined styles can be customized and applied based on attribute values.

   • Custom Symbols: Users can create and import custom symbols (such as PNG or SVG files) and apply them based on attribute values or other criteria.

3. External Links (Referenced Images):

   • URL-Based Symbology: In some cases, symbology can be defined using external links. For example, image URLs can be used to symbolize points with specific icons hosted externally.

   • Dynamic Web Maps: Web maps in ArcGIS Online or ArcGIS Enterprise can reference external images for symbols, allowing for dynamic updates without changing the underlying data.

Implementing Symbology Based on Database Columns

1. Attribute Table:

   • Ensure your dataset’s attribute table includes the necessary columns for defining symbology. For instance, if you are symbolizing by category, make sure there is a column that categorizes your data appropriately.

2. Setting Symbology in ArcGIS Pro:

   • Open Symbology Pane: Right-click the layer in the Table of Contents and select “Symbology.”

   • Choose Symbology Type: Select the appropriate symbology type (e.g., Single Symbol, Graduated Colors, Unique Values).

   • Assign Attributes: Set the attribute field(s) that will determine the symbology. Customize the appearance based on the attribute values.

3. Web Maps and Dashboards:

   • When creating web maps or dashboards in ArcGIS Online or ArcGIS Enterprise, configure the symbology in the web map settings. Attribute-based symbology can be set similarly to how it’s done in ArcGIS Pro.

Example: Symbology Based on Attribute Values

1. Categorical Symbology:

   • Unique Values: Use unique value symbology to assign different colors or symbols to different categories based on an attribute field (e.g., land use types, zoning categories).

2. Quantitative Symbology:

   • Graduated Colors: Use graduated color symbology to represent numerical ranges (e.g., population density, elevation).

   • Proportional Symbols: Use proportional or graduated symbol symbology to represent numerical values with varying symbol sizes.

3. Custom Symbols:

   • Import custom symbols (PNG, SVG) and apply them based on attribute values or conditions.

Summary

Symbology in ArcGIS is primarily driven by the attribute data stored in the database columns of your layers. This attribute-based symbology allows for dynamic, data-driven visualization. Additionally, external links or referenced images can be used for more customized or dynamic symbology needs, especially in web maps and applications.

By leveraging the power of attribute-based symbology and customizing it with styles and external resources, you can create highly informative and visually appealing maps in ArcGIS.

GIS Question of the Day #4 - Dashboard Items

Question:

In ArcGIS, there is an issue in dashboard list items the symbology(icons) and text are not aligned correctly to right. is this an issue choosing incorrect geometry (i.e. polygon for point data?) when designing layer /map?

Answer:

The misalignment of symbology (icons) and text in ArcGIS Dashboards is typically not caused by choosing incorrect geometry types (such as using polygons for point data) when designing your layer or map. Instead, this issue is more likely related to the configuration and styling settings within the dashboard itself. Here are a few steps to troubleshoot and resolve this issue:

Steps to Troubleshoot and Resolve Misalignment in ArcGIS Dashboards

1. Check Dashboard Configuration:

   • List Element Settings: Ensure that the settings for the list element in your dashboard are configured correctly. Check the alignment settings for both text and icons within the list element.

   • Text Formatting: Verify that the text formatting settings (such as padding, margins, and text alignment) are consistent and correctly applied.

2. Symbology Settings:

   • Icon Size and Position: Make sure that the size and position of the icons are consistent with the text. Sometimes, discrepancies in icon size or positioning can cause misalignment issues.

   • Layer Symbology: Ensure that the symbology settings in the map or layer used in the dashboard are correctly configured. Inconsistent symbology settings can sometimes propagate into the dashboard.

3. CSS and Custom Styling:

   • Custom CSS: If you have applied any custom CSS to the dashboard, ensure that the CSS rules are correctly targeting the elements and not causing unintended alignment issues.

   • Browser Compatibility: Test the dashboard in different browsers to rule out any browser-specific rendering issues that might affect alignment.

4. Data Integrity:

   • Geometry Type: While using incorrect geometry types (like polygons for point data) is not typically the cause of alignment issues in the dashboard, it’s good practice to use the appropriate geometry type for your data to ensure optimal performance and usability.

   • Attribute Data: Check that the attribute data used in the list element is correctly formatted and does not contain any unexpected values that might affect alignment.

5. Dashboard Layout:

   • Container Settings: Ensure that the containers or panels within the dashboard are properly configured. Misconfigured container settings can cause elements to be misaligned.

   • Responsive Design: Check the dashboard’s responsive design settings to ensure that elements are correctly aligned across different screen sizes and resolutions.

Example: Adjusting List Element Settings

1. Open your ArcGIS Dashboard and navigate to the list element with alignment issues.

2. Click on the settings (gear) icon for the list element.

3. In the settings panel, adjust the text alignment, padding, and margin settings to ensure they are consistent.

4. Adjust the icon size and position to ensure they align with the text.

5. Save the changes and preview the dashboard to see if the alignment issue is resolved.

Example: Verifying Symbology Settings

1. Open the map containing the layer used in the dashboard in ArcGIS Online or ArcGIS Pro.

2. Select the layer and check the symbology settings to ensure icons and symbols are correctly sized and positioned.

3. Save any changes and update the map in your dashboard.

By carefully checking these settings and configurations, you should be able to resolve the alignment issues in your ArcGIS Dashboard. If the problem persists, consider reaching out to Esri Support for further assistance.