makesymbolspec
Construct vector layer symbolization specification
Syntax
symbolspec = makesymbolspec(geometry,rule1,rule2,...ruleN)
Description
symbolspec = makesymbolspec(geometry,rule1,rule2,...ruleN) constructs
a symbol specification structure (symbolspec) for
symbolizing a (vector) shape layer in the Map Viewer or when using mapshow. geometry is
one of 'Point', 'Line', 'PolyLine', 'Polygon',
or 'Patch'. Rules, defined in detail below, specify
the graphics properties for each feature of the layer. A rule can
be a default rule that is applied to all features in the layer or
it may limit the symbolization to only those features that have a
particular value for a specified attribute. Features that do not match
any rules are displayed using the default graphics properties.
To create a rule that applies to all features, a default rule, use the following syntax:
{'Default',Property1,Value1,Property2,Value2,...
PropertyN,ValueN}To create a rule that applies only to features that have a particular value or range of values for a specified attribute, use the following syntax:
{AttributeName,AttributeValue,
Property1,Value1,Property2,Value2,...,PropertyN,ValueN}AttributeValue and ValueN can
each be a two-element vector, [low high], specifying
a range. If AttributeValue is a range, ValueN might
or might not be a range.
The following is a list of allowable values for PropertyN.
Points or Multipoints:
'Marker','Color','MarkerEdgeColor','MarkerFaceColor','MarkerSize', and'Visible'Lines or Polylines:
'Color','LineStyle','LineWidth', and'Visible'Polygons:
'FaceColor','FaceAlpha','LineStyle','LineWidth','EdgeColor','EdgeAlpha', and'Visible'
Examples
The following examples import a shapefile containing road data and symbolize it in several ways using symbol specifications.
Example 1 — Default Color
roads = shaperead('concord_roads.shp');
blueRoads = makesymbolspec('Line',{'Default','Color',[0 0 1]});
mapshow(roads,'SymbolSpec',blueRoads);
Example 2 — Discrete Attribute Based
roads = shaperead('concord_roads.shp');
roadColors = ...
makesymbolspec('Line',{'CLASS',2,'Color','r'},...
{'CLASS',3,'Color','g'},...
{'CLASS',6,'Color','b'},...
{'Default','Color','k'});
mapshow(roads,'SymbolSpec',roadColors);
Example 3 — Using a Range of Attribute Values
roads = shaperead('concord_roads.shp');
lineStyle = makesymbolspec('Line',...
{'CLASS',[1 3], 'LineStyle',':'},...
{'CLASS',[4 6],'LineStyle','-.'});
mapshow(roads,'SymbolSpec',lineStyle);
Example 4 — Using a Range of Attribute Values and a Range of Property Values
roads = shaperead('concord_roads.shp');
colorRange = makesymbolspec('Line',...
{'CLASS',[1 6],'Color',summer(10)});
mapshow(roads,'SymbolSpec',colorRange);