User's Reference - Caption

### Caption

Category

Annotation

Function

Displays a caption on the screen.

Syntax

    caption = Caption(string, position, flag, reference,
                      alignment, height, font, direction, up);

Inputs

Name | Type | Default | Description
--- | --- | --- | ---
`string` | string or string list | none | the caption to be displayed
`position` | vector | [0.5 0.05] | where to display the caption
`flag` | flag | 0 | 0: viewport-relative coordinates 1: pixel coordinates
`reference` | vector | same as `position` | reference point on caption
`alignment` | scalar | input dependent | range: 0.0: left-justify ... 1.0: right-justify
`height` | integer | 15 | caption height (pixels)
`font` | string | "variable" | caption font
`direction` | vector | [1 0] | direction of baseline
`up` | vector | perpendicular to baseline | direction of vertical strokes

Outputs

Name | Type | Description
--- | --- | ---
`caption` | color field | string object that can be rendered

Functional Details

The caption produced is aligned in parallel with the screen.

`string` | is the caption to be displayed. This parameter can also be a list of strings, for a multiline caption. Alternatively, you can separate substrings for a multiline caption by using \n.
`position` | specifies the position of the caption in units determined by `flag` (see below).
`flag` | determines the type of coordinates used in placing the caption: 0: viewport-relative 1: pixel
`reference` | specifies the reference point for the caption that is to be placed at `position`: [0 0] = bottom left of the caption [1 1] = top right If `flag` = 0, the default is the same as the current specification of `position`. If `flag` = 1, the default is the lower left corner of the caption.
`alignment` | determines the alignment of a multiline caption from left justified (0.0) to right justified (1.0). For intermediate values, justification is defined by linear interpolation (e.g., a value of 0.5 centers the lines).
`height` | determines the height of the caption characters in pixels. A negative value generates an inverted caption.
`font` | specifies the font for a displayed caption. You can specify any of the defined fonts supplied with Data Explorer. These include a variable-width font ("variable," the default) and a fixed-width font ("fixed"):
    area          gothicit_t       pitman                roman_ext
    cyril_d       greek_d          roman_d               script_d
    fixed         greek_s          roman_dser            script_s
    gothiceng_t   italic_d         roman_s               variable
    gothicger_t   italic_t         roman_tser
For more information, see Appendix E. "Data Explorer Fonts" in the IBM Visualization Data Explorer User's Guide.
`direction` | determines the orientation of the caption (i.e., the direction of its baseline).
`up` | determines the direction of the vertical strokes of the caption font.

Notes:

1. To change the color of a caption, use the Color module (see Color).

2. If you are using Render or Display to render an object which contains a caption, when you change the resolution of the camera the size of the caption in pixels will not change. If you want the caption to take up the same proportion of the image, use the ScaleScreen module to change the size of the caption.

Components

Creates "positions," "connections," and "colors" components.

Example Visual Programs

Many example visual programs use Caption, including:

    AlternateVisualizations.net
    ContoursAndCaption.net
    Sealevel.net
    UsingAttributes.net
    UsingIsosurface.net
    SIMPLE/Caption

    SIMPLE/ScaleScreen.net

See Also

Color, Format, Text, ScaleScreen, Legend

[ OpenDX Home at IBM | OpenDX.org ]