# ROLL

The ROLL function computes the third angle, in radians, of a body-3 Yaw-Pitch-Roll rotation sequence.

ROLL(I, J)

## Description

Given two coordinate systems, I and J, which are initially having the same orientation, this rotation sequence is defined as follows:
• First, rotate in a counterclockwise direction about the z-axis of the I coordinate system [YAW].
• Second, rotate counterclockwise about the negative y-axis of the I coordinate system [PITCH].
• Third, rotate counterclockwise about the x-axis of the I coordinate system [ROLL].

## Arguments

I
The marker whose rotational displacement is to be computed. Must be specified.
J
The marker with respect to which the rotational displacement is to be computed. This argument is optional. If omitted, it defaults to the ground coordinate system.

## Example

<Post_Request
comment  = "Vehicle Orientation (degrees)"
id       = "70000256"
type     = "EXPRESSION"
expr1    = "NULL"
expr2    = "YAW(30301010,30101010)*RTOD"
expr3    = "PITCH(30301010,30101010)*RTOD"
expr4    = "ROLL(30301010,30101010)*RTOD"/>