# PHI

The PHI function computes the third angle, in radians, of a body-2 Euler angle rotation sequence (body-3, body-1, body-3) of marker I with respect to marker J.

PHI(I, J)

## 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             = "O_PSI_T_Phi"
id                  = "70000013"
type                = "EXPRESSION"
expr1               = "NULL"
expr2               = "PSI(30102190)"
expr3               = "THETA(30102190)"
expr4               = "PHI(30102190)"
expr5               = "NULL"
expr6               = "NULL"
expr7               = "NULL"
expr8               = "NULL"
/>