Progression Frame

this element defines a specialized coordinate system with its z-axis is vertical, its x-axis is the gait direction and its y-axis is defined by a cross-product of these two axes and its direction from right to left side.

The content of the element is a mathematical formula (based only on marker trajectories!!!!!) which defines a point. Variables calculated by the model before can not be used because this gait direction is calculated before the step-by-step phase of the model.

The gait direction is defined by the vector defined by the position of this point at two different frames: start and end of a stride phase, as defined by the <GaitPhases> element. That means that the gait direction changes at every heel strike event of a given side. For frames before the first heel strike event and after the last heel strike event gait direction is extrapolated.

Attributes

Attribute Default Description Required
name
name of the element

Yes
leftHanded
false

The default orientation of the coordinate system is right-handed. If you set this attribute to "true" than the sign of the y-axis is changed to create a left-handed coordinate system.

No
gaitdirection
Schön wäre es ein Attribut zu haben mit dem ich explizit die Gangrichtung hineinstecken könnte. Per Default erbt die Klasse ja
von GaitDirectionStrideBased und so brauche ich in der Regel dieses Attribut nicht.
(not implemented yet)

No
visibleVectorLength
100

Wenn das Flag isVisible="true" gesetzt wurde, kann mit diesem Attribut die Länge der Vektoren zur Darstellung der Tripoden geändert werden.

No
Origin
(or the depreacted name origin)
point defined by the expression defined as content of the element

if the position defined by the expression in the content of the element should not be used as origin you can use this attribute to give an expression for the origin. This expression can include arbitrary variables - not only markers
(not tested)

No

Attributes inherited by <GaitDirectionCalcElementStrideBased

Attribute Default Description Required
Position
(deprecated)
Mathematical expression to describe the position, the gait direction is based on.
This attribute is deprecated. Better set the formula of the position as the elemements content.

No
stride
LStride if side="left"
RStride if side="right"

name of the stride used

No
side
right oder left?
vermutlich left

left or right

No

Note

The orientation of the axes is equivalent to the definition used by MoMo from Jan Simon.

Generated trajectories

name type description
<name>
3 x 3 matrix
<name>_X
3d vector

first column of the matrix <name>
<name>_Y
3d vector

second column of the matrix <name>
<name>_Z
3d vector

third column of the matrix <name>
<name>Position
3d vector

Expression for the position used to define the orientation of the frame
<name>Origin
3d vector

origin of the coordinate system
<name>xv
3d vector

vectors in direction of the coordinate system axes and with the length defined by the value of the attribute visibleVectorLength
<name>yv
<name>zv
<name>X0
3d vector

Points which represents end points of the arrows of coordinate axis. If an external visualization tool (Vicon Workstation) can visualize only points and not directly vectors, these points can be used in combination with the coordinates system origin to visualizes the axes by three lines with different length.
<name>Y0
<name>Z0

Note

<name> is the value of the elements name attribute.

Trajectories inherited from GaitDirectionCalcElement

name type description

<name>GaitDirection gait direction, equal to <name>_X

<name>GaitDirectionAngle

Examples

<GaitPhases name="GaitPhases"/>
<GaitCoordinateSystem name="RGait">(SACR+RASI+LASI)/3.0</GaitCoordinateSystem>

Gait phases must be defined first to use this element.

This definition is based on default values and defines a right handed gait coordinate system based on the stride defined by "RStride" phase type and the midpoint of the pelic.

Attribute	Default	Description	Required
name		name of the element	Yes
leftHanded	false	The default orientation of the coordinate system is right-handed. If you set this attribute to "true" than the sign of the y-axis is changed to create a left-handed coordinate system.	No
gaitdirection		Schön wäre es ein Attribut zu haben mit dem ich explizit die Gangrichtung hineinstecken könnte. Per Default erbt die Klasse ja von GaitDirectionStrideBased und so brauche ich in der Regel dieses Attribut nicht. (not implemented yet)	No
visibleVectorLength	100	Wenn das Flag isVisible="true" gesetzt wurde, kann mit diesem Attribut die Länge der Vektoren zur Darstellung der Tripoden geändert werden.	No
Origin (or the depreacted name origin)	point defined by the expression defined as content of the element	if the position defined by the expression in the content of the element should not be used as origin you can use this attribute to give an expression for the origin. This expression can include arbitrary variables - not only markers (not tested)	No

Attribute	Default	Description	Required
Position (deprecated)		Mathematical expression to describe the position, the gait direction is based on. This attribute is deprecated. Better set the formula of the position as the elemements content.	No
stride	LStride if side="left" RStride if side="right"	name of the stride used	No
side	right oder left? vermutlich left	left or right	No

name	type	description
<name>	3 x 3 matrix
<name>_X	3d vector	first column of the matrix <name>
<name>_Y	3d vector	second column of the matrix <name>
<name>_Z	3d vector	third column of the matrix <name>
<name>Position	3d vector	Expression for the position used to define the orientation of the frame
<name>Origin	3d vector	origin of the coordinate system
<name>xv	3d vector	vectors in direction of the coordinate system axes and with the length defined by the value of the attribute visibleVectorLength
<name>yv
<name>zv
<name>X0	3d vector	Points which represents end points of the arrows of coordinate axis. If an external visualization tool (Vicon Workstation) can visualize only points and not directly vectors, these points can be used in combination with the coordinates system origin to visualizes the axes by three lines with different length.
<name>Y0
<name>Z0