grayplot properties description of the grayplot entities properties

## Description

The Grayplot entity is a leaf of the graphics entities hierarchy. It represents 2D plots of surface using colors and images (see `grayplot`, `Sgrayplot`, `fgrayplot` and `Sfgrayplot`).

parent:

  This property contains the handle of the parent. The parent of the grayplot entity should be of the type `"Axes"`.

children:

  This property contains a vector with the `children` of the handle. However, `grayplot` handles currently do not have any `children`.

visible:

  This field contains the `visible` property value for the entity . It should be `"on"` or `"off"` . By default, the plot is visible, the value's property is `"on"`. If `"off"` the plot is not drawn on the screen.

data:

  This field defines a `tlist` data structure of type `"grayplotdata"` 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 field named `data.z` is the value of the surface at the point `(x(i),y(j))` (scaled mode) or the centered value of the surface defined between two consecutive `x(i)` and `y(j)` (direct mode). If `data_mapping` (see below) is set to `"scaled"`, the entire z data is used to perform a color interpolation whereas, if `data_mapping`'s value is `"direct"`, the last line and column of the z data indices are ignored and the color is determined directly in the colormap by the indices of the submatrix `data.z(1:$-1,1:$-1)`.

data_mapping:

  By default the value of this property is `"scaled"` : the indices of painting colors are proportional to the value `z` coordinates. In the other case, the property takes as value `"direct"` where the plot is a grayplot and the indices of painting colors are given by the data (see above).

clip_state:

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

  - `"off"` this means that the grayplot is not clipped.

  - `"clipgrf"` this means that the grayplot is clipped outside the Axes box.

  - `"on"` this means that the grayplot is clipped outside the rectangle given by property clip_box.

clip_box:

  This field is to determinate the `clip_box` property. By Default 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 grayplot to display, however `clip_state` property value will be changed.

user_data:

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

## Examples

    m=5;n=5;
    M=round(32*rand(m,n));
    grayplot(1:m,1:n,M)

    a=get("current_axes");
    a.data_bounds=  [-1,-1;7,7]
    h=a.children

    h.data_mapping="direct";

    // A 2D plotting of a matrix using colors
    clf()
    a=get("current_axes");
    a.data_bounds=  [0,0;4,4];

    b=5*ones(11,11); b(2:10,2:10)=4; b(5:7,5:7)=2;
    Matplot1(b,[1,1,3,3])  ;

    h=a.children
    for i=1:7
      xclick(); // click the mouse to sets Matplot data
      h.data=h.data+4;
    end

## See also

- set
- get
- delete
- grayplot
- Matplot
- Matplot1
- graphics_entities
- Matplot_properties