champ properties

Description

The Champ entity is a leaf of the graphics entities hierarchy. This entity defines the parameters for a 2D vector field.

visible:

This properties contains the visible property value for the entity . It should be "on" or "off" . If "on" the vector field is drawn, If "off" the vector field is not displayed on the screen.

data:

This field defines a tlist data structure of type "champdata" composed of a row and column indices of each element : the x and y grid coordinates are contained respectively in data.x and data.y. The complementary fields named data.fx and data.fy are matrices which describe respectively the x and y component of the vector field at point (x(i),y(j)).

user_data:

This field can be use to store any scilab variable in the champ data structure, and to retrieve it.

line_style:

The line_style property value should be an integer in [1 10]. 1 stands for solid, the other value stands for a selection of dashes (see getlinestyle).

thickness:

This property is a positive real specifying the arrow width in pixels. The displayed width is actually determined by rounding the supplied width to the nearest integer. The only exception is vectorial export where the whole thickness value is considered.

colored:

If this this property value is "on", fields vectors are drawn using a color proportional to the intensity of the field.

arrow_size:

This property is a double specifying the size of the arrow. The value can be positive or negative:

• arrow_size < 0: the arrows size is proportional to the average norm of the vectors.

• arrow_size > 0: the arrows size is proportional to the windows dimensions.

clip_state:

This field contains the clip_state property value for the champ. It should be :

• "off" this means that the vector field is not clipped

• "clipgrf" this means that the vector field is clipped outside the Axes box.

• "on" this means that the vector field is clipped outside the rectangle given by property clip_box.

clip_box:

This property contains the clip_box property. Its value should be an empty matrix if clip_state is "off" .Other cases the vector [x,y,w,h] (upper-left point width height) defines the portions of the vector field to display, however clip_state property value will be changed.

parent:

This property contains the handle of the parent. The parent of the 2D vector field entity should be of the type "Axes" or "Compound".

Examples

a = get("current_axes");   // get the handle of the newly created axes
a.data_bounds = [-10,-10 ; 10,10];
champ(-5:5, -5:5, rand(11,11), rand(11,11))

c = a.children
set(c, "colored","on", "thickness",2, "arrow_size",-1);
c.data    // display the tlist of type "champdata"
a.data_bounds = [-5,-5 ; 5,5];

See also

• set — set properties of some graphic objects or uimenus or uicontrol interactive components
• get — Gets the handle of a graphical or User Interface object, or the property's value of objects.
• delete — delete a graphic entity and its children.
• champ — plots as arrows a field of 2D vectors
• graphics_entities — description of the graphics entities data structures

History