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Classes

Class pv.Line


Extends pv.Mark.
Represents a series of connected line segments, or polyline, that can be stroked with a configurable color and thickness. Each articulation point in the line corresponds to a datum; for n points, n-1 connected line segments are drawn. The point is positioned using the box model. Arbitrary paths are also possible, allowing radar plots and other custom visualizations.

Like areas, lines can be stroked and filled with arbitrary colors. In most cases, lines are only stroked, but the fill style can be used to construct arbitrary polygons.

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

Class Summary
Constructor Attributes Constructor Name and Description
 
pv.Line()
Constructs a new line mark with default properties.
Field Summary
Field Attributes Field Name and Description
 
defaults
Default properties for lines.
 
eccentricity
The eccentricity of polar line segments; used in conjunction with interpolate("polar").
 
fillStyle
The line fill style; if non-null, the interior of the line is closed and filled with the specified color.
 
interpolate
How to interpolate between values.
 
lineJoin
The type of corners where two lines meet.
 
lineWidth
The width of stroked lines, in pixels; used in conjunction with strokeStyle to stroke the line.
 
segmented
Whether the line is segmented; whether variations in stroke style, line width and the other properties are treated as fixed.
 
strokeStyle
The style of stroked lines; used in conjunction with lineWidth to stroke the line.
 
tension
The tension of cardinal splines; used in conjunction with interpolate("cardinal").
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 line anchor with default properties.
Methods borrowed from class pv.Mark:
add, anchorTarget, def, event, extend, margin, mouse, render
Class Detail
pv.Line()
Constructs a new line mark with default properties. Lines are not typically constructed directly, but by adding to a panel or an existing mark via pv.Mark#add.
Field Detail
{pv.Line} defaults
Default properties for lines. By default, there is no fill and the stroke style is a categorical color. The default interpolation is linear.
{number} eccentricity
The eccentricity of polar line segments; used in conjunction with interpolate("polar"). The default value of 0 means that line segments are drawn as circular arcs. A value of 1 draws a straight line. A value between 0 and 1 draws an elliptical arc with the given eccentricity.
{string} fillStyle
The line fill style; if non-null, the interior of the line is closed and filled with the specified color. The default value of this property is a null, meaning that lines are not filled by default.

This property is fixed. See pv.Mark.

See:
pv.color
{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 a clockwise circular arc between points, specify "polar"; to draw a counterclockwise circular arc between points, specify "polar-reverse". To draw open uniform b-splines, specify "basis". To draw cardinal splines, specify "cardinal"; see also #tension.

This property is fixed. See pv.Mark.

{string} lineJoin
The type of corners where two lines meet. Accepted values are "bevel", "round" and "miter". The default value is "miter".

For segmented lines, only "miter" joins and "linear" interpolation are currently supported. Any other value, including null, will disable joins, producing disjoint line segments. Note that the miter joins must be computed manually (at least in the current SVG renderer); since this calculation may be expensive and unnecessary for small lines, specifying null can improve performance significantly.

This property is fixed. See pv.Mark.

{number} lineWidth
The width of stroked lines, in pixels; used in conjunction with strokeStyle to stroke the line.
{boolean} segmented
Whether the line is segmented; whether variations in stroke style, line width and the other properties are treated as fixed. Rendering segmented lines is noticeably slower than non-segmented lines.

This property is fixed. See pv.Mark.

{string} strokeStyle
The style of stroked lines; used in conjunction with lineWidth to stroke the line. The default value of this property is a categorical color.
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.

Method Detail
{pv.Anchor} anchor(name)
Constructs a new line anchor with default properties. Lines 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 outside the line. Note that this behavior is different from other mark anchors, which default to rendering text inside the mark.

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 a bar 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 Fri May 28 2010 10:13:29 GMT-0700 (PDT)