The FX measure returns the x-component of the net translational force acting on marker i, represented in the coordinate system of marker k. All force and constraint elements acting between markers i and j are included in the calculation of the force. If j is not specified, FX measures the sum of all force and constraint elements acting on marker i. If k not specified or if k=0, the force is represented in the GROUND coordinate system. To specify k without specifying j, use j=0.
Format
FX(i[,j][,k])
Arguments
i | An integer that specifies the identifier of the marker at which the magnitude of the net force is to be calculated. Objects using marker i (for example, SFORCE, JOINT) must be active. |
j | A second integer that specifies a marker identifier. All forces acting between the [i,j] pair are to be included in the calculation. Set j = 0 or do not specify if you are interested in all forces acting on marker i, for example, FX(i,0,k) will compute the sum of all forces acting on marker i. |
k | An integer that specifies the identifier of a marker (coordinate system) in which the x-component of the force is to be returned. k defaults to the global coordinate system when it is not specified. |
Examples
VARIABLE/1, FUNCTION=FX(23,0,432)
A user-defined state variable is specified by this VARIABLE statement. Its value is FX(23,0,432). This is the x-component of the sum of all the action-only forces acting at Marker 23 as computed in the coordinate system of Marker 432.