Compute Geometric Layout

The SURVEY command builds a table containing the geometric layout of the machine. The table can be referred to by its label for later manipulation. It has the following read/write attributes:

label:SURVEY,LINE=name,RANGE=range,REVERSE=logical,STATIC=logical,
      X0=real,Y0=real,Z0=real,THETA0=real,PHI0=real,PSI0=real;
label:SURVEY,LINE=name,RANGE=range,REVERSE=logical,STATIC=logical,
      INIT=table-row;

Its parameter list specifies the initial position and orientation of the reference orbit in the global coordinate system $(X, Y, Z)$. Omitted attributes assume zero values. Valid attributes are:

LINE

The label of a previously defined beam line (no default).

RANGE

If this attribute is given, the table is restricted to the range given.

STATIC

If this attribute is true, the table is filled at definition time, and it is then treated as frozen, even if parameters of the machine change.

INIT

If this attribute is given, the initial position and direction is taken from the specified row of another SURVEY table. If this attribute is omitted, the initial position and direction is constructed from the attributes listed below.

X0

The initial X coordinate [m].

Y0

The initial Y coordinate [m].

Z0

The initial Z coordinate [m].

THETA0

The initial angle theta [rad].

PHI0

The initial angle phi [rad].

PSI0

The initial angle psi [rad].

Example:

GEOMETRY:SURVEY,LINE=RING;

This example computes the machine layout for the line RING with zero initial conditions and saves the result under the name GEOMETRY.

The SURVEY table has some read-only attributes:

Table 7.1: Global read-only values in a SURVEY table

Variable	Unit	Name
Total arc length	m	L
Final X coordinate	m	X
Final Y coordinate	m	Y
Final Z coordinate	m	Z
Final angle theta	rad	THETA
Final angle phi	rad	PHI
Final angle psi	rad	PSI

In each position there are table values, each of which is accessible with the syntax

table-name "@" place "->" column-name

The azimuth, elevation angle, and roll angle are defined as the components of a vector. This vector points in the direction of the rotation axis and has the rotation angle as its length. The direction cosines are the components of the unit vectors along the local coordinate axes, expressed in the global coordinate system.

Table 7.2: Column values available in a SURVEY table

Variable	Unit	Name
Arc length from beginning	m	S
Global X coordinate	m	X
Global Y coordinate	m	Y
Global Z coordinate	m	Z
Azimuth	rad	THETA
Elevation angle	rad	PHI
Roll angle	rad	PSI

Direction cosines for local axes	Local axis
Global direction	x	y	s
X	W11	W12	W13
Y	W21	W22	W23
Z	W31	W32	W33

The default column set for the command LIST,ALL contains the element name, the arc length, the global positions and the three angles.