Name

LineSpec — to quickly customize the lines appearance in a plot

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 , plot , clf

Authors

F.Leray