Copyright © 2006 by Maribeth H. Price 4-1 Chapter 4 Drawing and Symbolizing Features
Copyright © 2006 by Maribeth H. Price 4-2 Outline Drawing features and rasters with different styles and symbols Using different types of maps to present attribute data Classifying features based on their attributes using a variety of classification methods Choosing, modifying, storing, and using different kinds of symbols Using layers and groups to speed and simplify display of data
Copyright © 2006 by Maribeth H. Price 4-3 Types of data Categorical data-- geology Quantities data-- precipitation Note: It’s unprofessional to use a GCS to create a map
Copyright © 2006 by Maribeth H. Price 4-4 Map Types Single symbol maps Unique values maps Quantities maps –Graduated color –Graduated symbol –Dot density Chart maps Multiple attribute maps Choose map type in Layer Properties
Copyright © 2006 by Maribeth H. Price 4-5 Single symbol maps
Copyright © 2006 by Maribeth H. Price 4-6 Unique Values Map
Copyright © 2006 by Maribeth H. Price 4-7 Types of unique values Many values-- State names Use to show different features Few values— State subregion Use to show patterns
Copyright © 2006 by Maribeth H. Price 4-8 Quantities maps
Copyright © 2006 by Maribeth H. Price 4-9 Types of Quantities Maps
Copyright © 2006 by Maribeth H. Price 4-10 Chart Maps Proportional chart map
Copyright © 2006 by Maribeth H. Price 4-11 Multiple attribute maps State subregion and population
Copyright © 2006 by Maribeth H. Price 4-12 Normalizing data By percent of total –Shows percentage of total By another field –Example: population/area gives population density
Copyright © 2006 by Maribeth H. Price 4-13 Ways to classify data Choose number of classes Variety of different classification methods –Jenks Natural Breaks –Equal Interval –Defined Interval –Quantile –Standard Deviation –Manual (set your own) Same data may appear differently
Copyright © 2006 by Maribeth H. Price 4-14 Jenks Natural Breaks Class breaks Exploits natural gaps in the data Good for unevenly distributed data Default method
Copyright © 2006 by Maribeth H. Price 4-15 Equal Interval Specify number of classes Divides into equally spaced classes
Copyright © 2006 by Maribeth H. Price 4-16 Defined interval User chooses the class size Data determines number of classes
Copyright © 2006 by Maribeth H. Price 4-17 Quantile Same number of features in each class May get very unevenly spaced class ranges
Copyright © 2006 by Maribeth H. Price 4-18 Standard Deviation Shows deviation from mean User chooses units e.g. 0.5 standard deviations
Copyright © 2006 by Maribeth H. Price 4-19 Classifying data Set manual breaks
Copyright © 2006 by Maribeth H. Price 4-20 Excluding data from classification
Copyright © 2006 by Maribeth H. Price 4-21 Using Symbols and Styles Symbols may be edited Group symbols together as Styles Use standard styles or create new ones
Copyright © 2006 by Maribeth H. Price 4-22 Symbol psychology Where is the water? Where is there less rain? Which towns have more people? What’s there?Where’s the danger?
Copyright © 2006 by Maribeth H. Price 4-23 Choosing symbols Which one looks more aesthetic? Which one is easier to understand? Which one shows the roads better?
Copyright © 2006 by Maribeth H. Price 4-24 Editing symbols Symbol Selector Symbol Property Editor Save edited symbols
Copyright © 2006 by Maribeth H. Price 4-25 Styles
Copyright © 2006 by Maribeth H. Price 4-26 The Style Manager
Copyright © 2006 by Maribeth H. Price 4-27 Using Layer Files Layer files store display information Can be saved and loaded Saves time recreating symbols
Copyright © 2006 by Maribeth H. Price 4-28 Displaying rasters
Copyright © 2006 by Maribeth H. Price 4-29 The raster data model Rows Columns X, Y location Raster data file N rows by M columns X, Y location Georeferenced to earth’s surface
Copyright © 2006 by Maribeth H. Price 4-30 Types of raster data Discrete raster: land use Continuous raster: DEM Continuous raster: image Discrete raster: roads
Copyright © 2006 by Maribeth H. Price 4-31 Raster Properties Scroll down for more info
Copyright © 2006 by Maribeth H. Price 4-32 Image types Single band image Three band composite image
Copyright © 2006 by Maribeth H. Price 4-33 RGB Color composites Image bands Composite color image
Copyright © 2006 by Maribeth H. Price 4-34 Stretching Original image Stretched image Enhances display by using greater range of brightness values
Copyright © 2006 by Maribeth H. Price 4-35 Single band display Unique values Classified
Copyright © 2006 by Maribeth H. Price 4-36 Single band display
Copyright © 2006 by Maribeth H. Price 4-37 Multi-band display
Copyright © 2006 by Maribeth H. Price 4-38 Grids Arc raster format Can be analyzed as well as displayed Has attribute table if discrete data
Copyright © 2006 by Maribeth H. Price 4-39 Nodata
Copyright © 2006 by Maribeth H. Price 4-40 Transparency Geology Hillshade