# WDTM

The WDTM function computes the magnitude of the total relative rotational acceleration between markers I and J. Time derivatives are calculated in the reference frame of marker L. The first argument, marker I, must be specified.

WDTM(I, J, L)

## Arguments

I
The marker whose acceleration is to be computed.
J
The marker with respect to which the acceleration is to be computed. If omitted, it defaults to the ground coordinate system.
L
Time derivatives are taken in the coordinate system of this marker. If omitted, it defaults to the ground coordinate system.

## Example

<Post_Request
comment          = "WM-WDTM-HAVSIN-FORSIN-DIM-ACOS"
id               = "3"
type             = "EXPRESSION"
expr1            = "NULL"
expr2            = "WM(30102010)"
expr3            = "WDTM(30102010)"
expr4            = "HAVSIN(TIME,1.,0.,4.,1.)"
expr5            = "NULL"
expr6            = "FORSIN(TIME,0.1,6.28,0.1,0.2)"
expr7            = "DIM(TIME,1.0)"
expr8            = "ACOS(COS(TIME))"
/>