Defining Attributes

The DATT command defines an attribute table entry and sets that attribute as the current default. DATT has the following definition:

DATT name=colours,lst,lpc,tht,twd,tsp,tsl,font
name	Up to a 15 character attribute name. Note: attribute names are case-sensitive.
=colours	Line and fill colour settings, and line thickness. Colours are defined by specifying one or more colour letters, each followed by an optional colour intensity between 0 and 255. Lines are specified in lower case, while fill is specified with the upper case letter. The letters used are:
	k,K	blacK
	c,C	Cyan
	m,M	Magenta
	y,Y	Yellow
	r,R	Red (magenta and yellow)
	g,G	Green (cyan and yellow)
	b,B	Blue (cyan and magenta)
	t	line thickness in microns (default 1)
	Lower-case letters (kcmyrgb) set the line colour. Upper-case letters (KCMYRGB) set the fill colour. If a colour intensity is omitted, an intensity of 255 (full intensity) is used. The default line and fill colours are black and white respectively. For example, both k64bM and k64cmM are dark blue lines (cyan and magenta are equivalent to blue) and the fill colour is set to full intensity magenta.
lst	Line style:
	1	solid (default).
	2	long dashes.
	3	dotted.
	4	short dashes.
	5	long/short/long dashes.
	6	long/dot/long dash.
	If the style is negative, then a smooth joining line is used. The default is a solid style, with a straight joining line (+1).
lpt	Line pitch. The default is 0.5 cm.
tht	Text height in map units. The default is 0.3 cm.
twd	Text width in map units. The default is 0.3 cm.
tsp	Text spacing in map units. The default is 0.3 cm.
tsl	Text slant in degrees. The default is a 0 degree slant.
font	Text font name. The default font is DEFAULT.

For example, the following defines an attribute entry named house, which will use a 500 micron black solid line and yellow colour fill:

To use an attribute, specify the name of the attribute in the graphics command. For example, to draw a rectangle using attribute house, the command would be:

When an attribute name is not specified, the current default attribute defined by the last DATT command is assumed.

If a named attribute is used and it has not been previously defined with a DATT command, it is created with default settings. You have the option to set the line and fill colours, and the line thickness attributes by following the attribute name by an "="sign and a colour setting string. The following is equivalent to both the DATT and RECT commands of the previous example

This will create an attribute named house if it does not exist, and set the attributes as defined. Note that if house did exist, its attribute settings would have been changed, and this change will affect all previous entities that used attribute house.

Attribute Overrides

Attribute overrides also define attributes, but become part of a graphics entity and cannot be changed by changing the attribute table. Entities drawn by MAPPLOT will allow you to specify attribute overrides by defining attributes with the graphics command. For example, the following command plots a rectangle using the house attribute table entry, but specifies a line style (3) and pitch (0.5) attribute override:

Attribute overrides remain in effect for all entities that follow until the next command that specifies an attribute name. In the following example, the first rectangle uses house with no overrides, the next two use line style overrides, and the last rectangle again uses house with no overrides:

DATT house,kYt500	\define attribute house
RECT 0,10,5,15,10	\use default attribute house
RECT 0,20,5,25,10,,3,0.5	\use house with style override
RECT 0,30,5,35,10	\override still applies
RECT 0,40,5,45,10,house	\house with no overrides

Attribute overrides may also be applied to line colours, fill colours and thickness by following the attribute name with a colon and the override specification. The following command plots a house with a red outline, but still associates the rectangle with the house attribute:

Colour and thickness overrides will also be passed on to following commands that do not specify an attribute name, in which case they will use the currently active default attribute and overrides.