Format

VR(I, J, L)

Description

Returns the relative velocity of marker I with respect to J.  Time derivatives are computed in the reference frame of marker L.  Markers J and K are optional.

Example

<Force_Scalar_TwoBody

    id             = "101001"

    type           = "Force"

    i_marker_id    = "10508"

    body1_id       = "105"

    j_marker_id    = "10307"

    body2_id       = "103"

    val_expression = "100-0.1*VR(10508,10307)"

/>

Arguments

I

The marker whose velocity is to be computed.

J

The marker with respect to which the velocity is to be computed.  This argument is optional.  If omitted, it defaults to the ground coordinate system.

L

Time derivatives are taken in the coordinate system of this marker.  This argument is optional.  If omitted, it defaults to the ground coordinate system.