# WDTX

The WDTX function computes the X-component of the relative rotational acceleration of marker I with respect to marker J, as resolved in the coordinate system of marker K. The time derivatives are taken in the marker L frame. The first argument, marker I, must be specified.

WDTX(I, J, K, L)

## Description

The second, third and fourth arguments (markers J, K and L) are optional.

## 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.
K
The resultant acceleration vector is resolved in the coordinate system of the K marker. 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          = "acc-expr"
id               = "70000044"
type             = "EXPRESSION"
expr1            = "NULL"
expr2            = "ACCX(30301010,30301011,30301011)"
expr3            = "ACCY(30301010,30301011,30301011)"
expr4            = "ACCZ(30301010,30301011,30301011)"
expr5            = "NULL"
expr6            = "WDTX(30301010,30301011,30301011)"
expr7            = "WDTY(30301010,30301011,30301011)"
expr8            = "WDTZ(30301010,30301011,30301011)"
/>