• Introduction
• The Utility of Maps
• Producing Displays
• Point Symbolization
• Line Symbolization
• Choropleth Symbolization
• Graduated Symbol
• Grid Symbolization
  • Monovariate
  • Multivariate
• Dot Density Symbolization
• Isopleth Symbolization
• Thematic Mapping
• References
• Index
• Author Index
• Symbol Index
• Site Map

Monovariate Symbolization

Because of the limitations of ARC/INFO, which reflect the nature of the raster data model, single grid layers can only be displayed with hue, value or intensity (not used here). A grid cell is generally represented by a single pixel, which prevents use of area fills based on shape, texture, etc.

Nominal Data--Hue

Figure 7.1a: RH.aml Grided (raster) nominal data displayed with color hue.

Color hue is best used for nominal data. Because of this, RH.aml takes a lookup table generated by SETMAN.aml--the method for creating nominal, grid lookup tables. Legends for hue and value based displays can be generated with AL.aml. See Figure 7.1a.

RH <hue_lookup> {value} {intensity}

<hue_lookup>

specifies HLS hue (from 0 to 300)

{value} {intensity}

default to 50 and 100 (maximum intensity).

Ordinal to Ratio Data--Value

Figure 7.1b: RV.aml Girded ratio data displayed with value. Like the color hue display, legends for this type of data can be displayed with AL.aml.

Because color value is best for ordinal data, this AML requires a lookup table generated by GRIDLUT.aml. For grid layers in which the middle value is important, the lookup table should be generated with the mean and standard deviation method, otherwise equal intervals is probably better. See Figure 7.1b and RV.aml.

RV <value_lookup> {hue} {intensity}

<value_lookup>

specifies HLS lightness (from 0 to 100)

{hue} {intensity}

specify a color to be value shaded--defaults to 0 and 0.