LineSpec — to quickly customize the lines appearance in a plot
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).
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 |
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 |
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) |
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')