`<regionHalfPlane/>`

A half-plane region bounded by a line

<regionHalfPlane/> is a Graphical component that represents one side of the plane bounded by a vertical or horizontal line. It does not render anything by itself; its role is to act as a region passed to a constraint such as <constrainTo> or <constrainToInterior>, restricting a <point> to that half-plane.

With the default attributes the region is the right half-plane $x \ge 0$ .

Attributes and Properties

Attributes for `<regionHalfPlane>`

Labels (1)

labelIsName

boolean. Default value: false. Whether to use this component's name as its rendered label.

Other (6)

applyStyleToLabel

boolean. Default value: false. Whether to apply this component's selected style to its label.

boundaryValue

number. Default value: 0. Position of the bounding line: x = boundaryValue when horizontal is true, y = boundaryValue when horizontal is false.

greaterThan

boolean. Default value: true. Whether the region is the side where the inequality is greater than the boundary.

horizontal

boolean. Default value: true. Whether the half-plane extends horizontally, bounded by the vertical line x = boundaryValue. If false, the half-plane extends vertically, bounded by the horizontal line y = boundaryValue.

layer

integer. Default value: 0. Z-order layer index used to stack graphical components (higher values render on top).

maskLabel

boolean. Default value: false. Whether to give the label an opaque background so it stays legible when it overlaps an axis, grid line, or another object.

Common to all components (9)

copy

reference. Create an independent copy of another component by reference. Enter a references a $name.

disabled

boolean. Default value: false. Whether this component is disabled and cannot be interacted with.

extend

reference. Extend another component by reference, inheriting its children and attributes. Enter a reference as $name.

fixed

boolean. Default value: false. Whether this component's value is fixed and cannot be modified.

fixLocation

boolean. Default value: false. Whether this component's location is fixed (preventing it from being moved while still allowing other modifications).

hide

boolean. Default value: false. Whether to hide this component from the rendered output.

isResponse

boolean. Default value: false. Whether this component is treated as a response for the purposes of assessment.

name

text. The name used to reference this component from elsewhere in the document.

styleNumber

integer. Default value: 1. The style number used to select this component's visual styling from the available style definitions.

Properties for `<regionHalfPlane name="r">`

Labels (2)

$r.label

label. The label rendered with this component.

$r.labelIsName

boolean. Whether to use this component's name as its rendered label.

Other (10)

$r.applyStyleToLabel

boolean. Whether to apply this component's selected style to its label.

$r.boundaryValue

number. Position of the bounding line: x = boundaryValue when horizontal is true, y = boundaryValue when horizontal is false.

$r.disabled

boolean. Whether this component is disabled and cannot be interacted with.

$r.fixed

boolean. Whether this component's value is fixed and cannot be modified.

$r.fixLocation

boolean. Whether this component's location is fixed (preventing it from being moved while still allowing other modifications).

$r.greaterThan

boolean. Whether the region is the side where the inequality is greater than the boundary.

$r.hidden

boolean. Whether this component is hidden from the rendered output.

$r.horizontal

boolean. Whether the half-plane extends horizontally, bounded by the vertical line x = boundaryValue. If false, the half-plane extends vertically, bounded by the horizontal line y = boundaryValue.

$r.layer

integer. Z-order layer index used to stack graphical components (higher values render on top).

$r.maskLabel

boolean. Whether to give the label an opaque background so it stays legible when it overlaps an axis, grid line, or another object.

Common to all components (4)

$r.doenetML

text. The DoenetML source code that produced this component.

$r.hide

boolean. Whether to hide this component from the rendered output.

$r.isResponse

boolean. Whether this component is treated as a response for the purposes of assessment.

$r.styleNumber

integer. The style number used to select this component's visual styling from the available style definitions.

Examples

Example: Constrain a `<point>` to the right half-plane

The point can be moved freely in the right half-plane and is held against the $y$ -axis when dragged to the left. The defaults — horizontal="true", boundaryValue="0", greaterThan="true" — describe the half-plane $x \ge 0$ .

Attribute Examples

Attribute Example: horizontal

When horizontal is false, the half-plane extends vertically instead of horizontally. Combined with the default boundaryValue="0" and greaterThan="true", this is the upper half-plane $y \ge 0$ .

Attribute Example: boundaryValue

boundaryValue shifts the bounding line. With horizontal="true" (the default), it sets the vertical boundary $x = 2$ .

Attribute Example: greaterThan

Setting greaterThan to false selects the opposite side of the boundary. The combination of horizontal="false" and greaterThan="false" here gives the lower half-plane $y \le 0$ .

regionBetweenCurveXAxis regularPolygon (Page 1)

<regionHalfPlane/>