`<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 (5)

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).

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 (9)

$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).

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/>