Chapter 2 Flashcards
(40 cards)
Nominal Data
values that name or identify an object, such as a street name.
Categorical Data
Data that place objects into unranked groups; examples are land use or geology data.
Numeric Data
values stored as numbers rather than as names or categories.
Unique Values Map
A map type in which each attribute value is assigned its own symbol
Ordinal Data
Rank objects without a regular scale.
Ratio Data
Data having a regular scale of measurement and a natural zero point, such as precipitation or population.
Interval Data
Values that follow a regular scale but have no natural zero point, such as degrees Celsius or pH.
Graduated Symbol Map
A map that divides numeric data from a line or point feature class into classes based on value and displays the classes with different size or thickness of symbols.
Proportional Symbol Map
A map that displays attribute values with marker or line symbols that are proportional in size relative to the value of the feature.
Graduated Color Map
A map that divides numeric data from a polygon feature class into classes based on value and displays the classes with different colors.
Choropleth Map
Maps in which each feature, such as a a state, is colored according to the value in a data field.
Normalized Data
To divide the values of an attrubute field by the total of the field or my the values in another field.
Dot Density Map
A map representing attribute values by a proportional number of randomly place dots.
Chart Map
Map showing several different attributes in chart form, with one chart for each feature.
Thematic Rasters
A raster that contains categorical or nominal data values, such as land use codes or soil types.
Unique Values
A map type in which each attribute value is assigned its own symbol.
Classified
A raster display method that dividies values into two or more groups based on their numeric values.
Stretched
A display method that spreads the data values over the entire range of symbols available.
Slice
To divide the value in a raster into a specified number of even classes.
Image Rasters
A raster data layer, usually referring to a raster that displays brightness values, as in a photogragh.
Histogram
A graph showing the number of pixels contained for each data value in a raster.
Colormap
A set of defined colors matched to specific image pixel values, which determine how the image will appear.
Classification
Assigning features to two or more groups based on numeric values in an attribute field.
Jenks Method
A way to classify numeric data into ranges defined by naturally occurring gaps in the data histogram.
