LineSpec

Description

The LineSpec is an optional argument that can be used inside a plot command to customize each new line aspect. It has to be given as a concatenated string containing information about color, line style or markers. It is very usefull to quickly specify such basic line properties.

To specify a red longdash-dot with diamond marker, the string can be 'r-.diam'. As you can see, a full complete spelling of each property value is not required but the string, which is a concatenation (in any order) of these three types of properties , must remain unambiguous. Furthermore, the string specification is not case sensitive.

Here is a complete list of the LineSpec types you can specify (using plot).

LineStyle:

a string defining the line style. This property is linked to the object's line_style property (see polyline_properties).

Specifier	Line Style
-	Solid line (default)
--	Dashed line
:	Dotted line
-.	Dash-dotted line

Color:

a string defining the line color. This property is linked to the object's foreground property (see polyline_properties).

Specifier	Color
r	Red
g	Green
b	Blue
c	Cyan
m	Magenta
y	Yellow
k	Black
w	White

A default color table is used to color plotted curves if you do not specify a color (neither with LineSpec nor with GlobalProperty). When drawing multiple lines, the plot command automatically cycles through this table. Here are the used colors:

R	G	B
0.	0.	1.
0.	0.5	0.
1.	0.	0.
0.	0.75	0.75
0.75	0.	0.75
0.75	0.75	0.
0.25	0.25	0.25

Marker type:

A string defining the marker type. note that if you specify a marker wihtout a line style, only the marker is drawn. This property is linked to the object's mark_style and mark_mode properties (see polyline_properties).

Specifier	Marker Type
+	Plus sign
o	Circle
*	Asterisk
.	Point
x	Cross
'square' or 's'	Square
'diamond' or 'd'	Diamond
^	Upward-pointing triangle
v	Downward-pointing triangle
>	Right-pointing triangle
<	Left-pointing triangle
'pentagram'	Five-pointed star (pentagram)
'none'	No marker (default)

Examples

x=1:0.1:10; // Init.
plot(x,sin(x),'r.->') // plots a dash-dotted line with a right-pointing triangle centered on each points.
clf();

// If you specify a marker wihtout a line style, only the marker is drawn
plot(x,sin(x),'d') // plots a dash-dotted line with a right-pointing triangle centered on each points.

x=1:10; // Init.
// combinations' order does not matter
plot(x,x.*x,'*cya--') 

//multiple plots with different LineSpecs
clf();
t=0:%pi/20:2*%pi;
plot(t,sin(t),'ro-.',t,cos(t),'cya+',t,abs(sin(t)),'--mo')

See Also

• GlobalProperty — to customize the objects appearance (curves, surfaces...) in a plot or surf command.
• plot — 2D plot
• clf — clear or reset the current graphic figure (window) to default values

Authors

F.Leray