IBM Visualization Data Explorer User's Reference

ColorBar

Category

Function

Creates a color bar.

Syntax

colorbar = ColorBar(colormap, position, shape, horizontal, ticks,
                    min, max, colors, annotation, labelscale, font);

Inputs

Name Type Default Description
colormap field none color map
position vector [0.95, 0.95] the position of the color bar (in viewport-relative coordinates)
shape vector [300 25] length and width of the color bar (in pixels)
horizontal flag 0 0: vertical orientation
1: horizontal orientation
ticks integer input dependent approximate number of tick marks along the bar
min scalar or object map min minimum value on bar
max scalar or object map max maximum value on bar
label string no defaults label for color bar
colors vector list or string list appropriate colors for annotation
annotation string list "all" annotation objects to be colored
labelscale scalar 1.0 scale factor for labels
font string standard font for labels
ticklocations scalar list appropriate tick locations
ticklabels string list ticklocations tick labels

Name	Type	Default	Description
`colormap`	field	none	color map
`position`	vector	[0.95, 0.95]	the position of the color bar (in viewport-relative coordinates)
`shape`	vector	[300 25]	length and width of the color bar (in pixels)
`horizontal`	flag	0	0: vertical orientation 1: horizontal orientation
`ticks`	integer	input dependent	approximate number of tick marks along the bar
`min`	scalar or object	map min	minimum value on bar
`max`	scalar or object	map max	maximum value on bar
`label`	string	no defaults	label for color bar
`color`s	vector list or string list	appropriate	colors for annotation
`annotation`	string list	"all"	annotation objects to be colored
`labelscale`	scalar	1.0	scale factor for labels
`font`	string	standard	font for labels
`ticklocations`	scalar list	appropriate	tick locations
`ticklabels`	string list	ticklocations	tick labels

Outputs

Name Type Description
colorbar color field the color bar

Name	Type	Description
`colorbar`	color field	the color bar

Functional Details

The color bar generated by this module can be collected with the rest of the objects in the scene (by using a Collect module) and incorporated into an image.

colormap
must be a color map (e.g., the second output of AutoColor or the first output of the Colormap Editor). The input can also be an imported .cm file (see Import), in which case the color-map part of the color-opacity map is extracted and used. (A color map has a 1-dimensional "positions" component, representing the data values, and a 3-dimensional "data" component, representing the RGB color assigned to each data value.)
position
is a 2-dimensional vector (or a 3-dimensional vector whose z-component is ignored) indicating the position of the color bar in the final image. In viewport-relative coordinates, [0 0] places the bar at the lower left, and [1 1] at the upper right. These same coordinates determine the reference point that is used to position the bar relative to its placement in the image (e.g., for position = [0 0], the lower left corner of the bar is placed in the lower left corner of the image).
shape
is a 2-vector that specifies the length and width of the color bar, in pixels. For both horizontal and vertical orientations, the first element of the vector is the length and the second is the width.
horizontal
determines whether the orientation of the color bar is vertical (0) or horizontal (1).
ticks
specifies the number of tick marks to be placed on the color bar (the actual number will at least approximate the specification). The default varies the number in accord with the size of the bar.
min and max
specify the limits of the color bar. The values can be scalar. If min is an object (a data field), the minimum and maximum data values of that field are used to set the corresponding limits of the bar. If min is scalar and max is an object (a data field), the maximum is the maximum data value of that field. When neither is specified, the minimum and maximum used are those of colormap.
label
specifies a user-supplied label for the color bar.
colors and annotation
set the colors of certain components of the color bar.
colors can be a single color (RGB vector or color-name string) or a list. The color-name string must be one of the defined color names (see Color).
annotation can be a single string or a list of strings, chosen from the following: "all.," "frame," "labels," and "ticks."
If annotation is not specified or is "all"--and if colors is a single string--then colors is used for all color-bar annotation. Otherwise the number of colors must match the number of annotation strings exactly. The default frame color is "clear."
labelscale
determines the size of the axes and tick-mark labels. For example, labelscale = 2.0 will display the labels at double their default size.
font
specifies the font used for axes and tick-mark labels. You can specify any of the defined fonts supplied with Data Explorer. These include a variable-width font ("variable", the default for axes labels) and a fixed-width font ("fixed", the default for tick-marks labels).
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 IBM Visualization Data Explorer User's Guide.
ticklocations
specifies the explicit location for tick marks. If specified, overrides the value as determined by ticks.
ticklabels
specifies the list of labels to be associated with the tick locations specified by ticklocations. If ticklabels is specified, and ticklocations is not specified, then ticklocations defaults to the integers 0 to n-1 where n is the number of items in ticklabels.

Notes:

min and max, if given, or the extent of the data if min and max are not given, set the extent of the color bar.

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

Example Visual Programs


BandedColors.net

Sealevel.net
UsingColormaps.net
UsingIsosurface.net
VolumeRendering.net
SIMPLE/ColorBar.net

SIMPLE/ScaleScreen.net

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`colormap`	must be a color map (e.g., the second output of AutoColor or the first output of the Colormap Editor). The input can also be an imported `.cm` file (see Import), in which case the color-map part of the color-opacity map is extracted and used. (A color map has a 1-dimensional "positions" component, representing the data values, and a 3-dimensional "data" component, representing the RGB color assigned to each data value.)
`position`	is a 2-dimensional vector (or a 3-dimensional vector whose z-component is ignored) indicating the position of the color bar in the final image. In viewport-relative coordinates, [0 0] places the bar at the lower left, and [1 1] at the upper right. These same coordinates determine the reference point that is used to position the bar relative to its placement in the image (e.g., for `position` = [0 0], the lower left corner of the bar is placed in the lower left corner of the image).
`shape`	is a 2-vector that specifies the length and width of the color bar, in pixels. For both horizontal and vertical orientations, the first element of the vector is the length and the second is the width.
`horizontal`	determines whether the orientation of the color bar is vertical (0) or horizontal (1).
`ticks`	specifies the number of tick marks to be placed on the color bar (the actual number will at least approximate the specification). The default varies the number in accord with the size of the bar.
`min` and `max`	specify the limits of the color bar. The values can be scalar. If `min` is an object (a data field), the minimum and maximum data values of that field are used to set the corresponding limits of the bar. If `min` is scalar and `max` is an object (a data field), the maximum is the maximum data value of that field. When neither is specified, the minimum and maximum used are those of `colormap`.
`label`	specifies a user-supplied label for the color bar.
`colors` and `annotation`	set the colors of certain components of the color bar. `colors` can be a single color (RGB vector or color-name string) or a list. The color-name string must be one of the defined color names (see Color). `annotation` can be a single string or a list of strings, chosen from the following: "all.," "frame," "labels," and "ticks." If `annotation` is not specified or is "all"--and if `colors` is a single string--then `colors` is used for all color-bar annotation. Otherwise the number of colors must match the number of annotation strings exactly. The default frame color is "clear."
`labelscale`	determines the size of the axes and tick-mark labels. For example, `labelscale` = 2.0 will display the labels at double their default size.
`font`	specifies the font used for axes and tick-mark labels. You can specify any of the defined fonts supplied with Data Explorer. These include a variable-width font ("variable", the default for axes labels) and a fixed-width font ("fixed", the default for tick-marks labels). 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 IBM Visualization Data Explorer User's Guide.
`ticklocations`	specifies the explicit location for tick marks. If specified, overrides the value as determined by `ticks`.
`ticklabels`	specifies the list of labels to be associated with the tick locations specified by `ticklocations`. If `ticklabels` is specified, and `ticklocations` is not specified, then `ticklocations` defaults to the integers 0 to n-1 where n is the number of items in `ticklabels`.