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Classes


Class pv.Area


Extends pv.Mark.
Represents an area mark: the solid area between two series of connected line segments. Unsurprisingly, areas are used most frequently for area charts.

Just as a line represents a polyline, the Area mark type represents a polygon. However, an area is not an arbitrary polygon; vertices are paired either horizontally or vertically into parallel spans, and each span corresponds to an associated datum. Either the width or the height must be specified, but not both; this determines whether the area is horizontally-oriented or vertically-oriented. Like lines, areas can be stroked and filled with arbitrary colors.

See also the Area guide.
Defined in: Area.js.

Class Summary
Constructor Attributes Constructor Name and Description
 
Constructs a new area mark with default properties.
Field Summary
Field Attributes Field Name and Description
 
Default properties for areas.
 
The area fill style; if non-null, the interior of the polygon forming the area is filled with the specified color.
 
The height of a given span, in pixels; used for vertical spans.
 
How to interpolate between values.
 
The width of stroked lines, in pixels; used in conjunction with strokeStyle to stroke the perimeter of the area.
 
Whether the area is segmented; whether variations in fill style, stroke style, and the other properties are treated as fixed.
 
The style of stroked lines; used in conjunction with lineWidth to stroke the perimeter of the area.
 
The tension of cardinal splines; used in conjunction with interpolate("cardinal").
 
The width of a given span, in pixels; used for horizontal spans.
Fields borrowed from class pv.Mark:
bottom, childIndex, cursor, data, events, index, left, parent, proto, reverse, right, root, scale, title, top, type, visible
Method Summary
Method Attributes Method Name and Description
 
anchor(name)
Constructs a new area anchor with default properties.
Methods borrowed from class pv.Mark:
add, anchorTarget, def, event, extend, margin, mouse, render
Class Detail
pv.Area()
Constructs a new area mark with default properties. Areas are not typically constructed directly, but by adding to a panel or an existing mark via pv.Mark#add.
Field Detail
{pv.Area} defaults
Default properties for areas. By default, there is no stroke and the fill style is a categorical color.

{string} fillStyle
The area fill style; if non-null, the interior of the polygon forming the area is filled with the specified color. The default value of this property is a categorical color.

This property is fixed for non-segmented areas. See pv.Mark.

See:
pv.color

{number} height
The height of a given span, in pixels; used for vertical spans. If the height is specified, the width property should be 0 (the default). Either the left or right property should be used to space the spans horizontally, typically as a multiple of the index.

{string} interpolate
How to interpolate between values. Linear interpolation ("linear") is the default, producing a straight line between points. For piecewise constant functions (i.e., step functions), either "step-before" or "step-after" can be specified. To draw open uniform b-splines, specify "basis". To draw cardinal splines, specify "cardinal"; see also #tension.

This property is fixed. See pv.Mark.


{number} lineWidth
The width of stroked lines, in pixels; used in conjunction with strokeStyle to stroke the perimeter of the area. Unlike the Line mark type, the entire perimeter is stroked, rather than just one edge. The default value of this property is 1.5, but since the default stroke style is null, area marks are not stroked by default.

This property is fixed for non-segmented areas. See pv.Mark.


{boolean} segmented
Whether the area is segmented; whether variations in fill style, stroke style, and the other properties are treated as fixed. Rendering segmented areas is noticeably slower than non-segmented areas.

This property is fixed. See pv.Mark.


{string} strokeStyle
The style of stroked lines; used in conjunction with lineWidth to stroke the perimeter of the area. Unlike the Line mark type, the entire perimeter is stroked, rather than just one edge. The default value of this property is null, meaning areas are not stroked by default.

This property is fixed for non-segmented areas. See pv.Mark.

See:
pv.color

{number} tension
The tension of cardinal splines; used in conjunction with interpolate("cardinal"). A value between 0 and 1 draws cardinal splines with the given tension. In some sense, the tension can be interpreted as the "length" of the tangent; a tension of 1 will yield all zero tangents (i.e., linear interpolation), and a tension of 0 yields a Catmull-Rom spline. The default value is 0.7.

This property is fixed. See pv.Mark.


{number} width
The width of a given span, in pixels; used for horizontal spans. If the width is specified, the height property should be 0 (the default). Either the top or bottom property should be used to space the spans vertically, typically as a multiple of the index.
Method Detail
{pv.Anchor} anchor(name)
Constructs a new area anchor with default properties. Areas support five different anchors:In addition to positioning properties (left, right, top bottom), the anchors support text rendering properties (text-align, text-baseline). Text is rendered to appear inside the area. The area anchor also propagates the interpolate, eccentricity, and tension properties such that an anchored area or line will match positions between control points.

For consistency with the other mark types, the anchor positions are defined in terms of their opposite edge. For example, the top anchor defines the bottom property, such that an area added to the top anchor grows upward.

Parameters:
{string} name
the anchor name; either a string or a property function.
Returns:
{pv.Anchor}

Documentation generated by JsDoc Toolkit 2.3.2 on Sun May 30 2010 18:10:23 GMT-0700 (PDT)