The <marker> element defines the graphic that is to be used for drawing arrowheads or polymarkers on a given <path>, <line>, <polyline> or <polygon> element.
markerHeightThis attribute defines the height of the marker viewport. Value type: <length> ; Default value: 3; Animatable: yesmarkerUnitsThis attribute defines the coordinate system for the attributes markerWidth, markerHeight and the contents of the <marker>. Value type: userSpaceOnUse|strokeWidth ; Default value: strokeWidth; Animatable: yesmarkerWidthThis attribute defines the width of the marker viewport. Value type: <length> ; Default value: 3; Animatable: yesorientThis attribute defines the orientation of the marker relative to the shape it is attached to. Value type: auto|auto-start-reverse|<angle> ; Default value: 0; Animatable: yespreserveAspectRatioThis attribute defines how the svg fragment must be deformed if it is embedded in a container with a different aspect ratio. Value type: (none| xMinYMin| xMidYMin| xMaxYMin| xMinYMid| xMidYMid| xMaxYMid| xMinYMax| xMidYMax| xMaxYMax) (meet|slice)? ; Default value: xMidYMid meet; Animatable: yesrefXThis attribute defines the x coordinate for the reference point of the marker. Value type: left|center|right|<coordinate> ; Default value: 0; Animatable: yesrefYThis attribute defines the y coordinate for the reference point of the marker. Value type: top|center|bottom|<coordinate> ; Default value: 0; Animatable: yesviewBoxThis attribute defines the bound of the SVG viewport for the current SVG fragment. Value type: <list-of-numbers> ; Default value: none; Animatable: yes