# GRID

Model ElementGRID defines an NLFE node in 3D space.

## Description

The definition of a GRID contains the following information:
• Current location in space (X, Y, and Z coordinates)
• Relaxed location in space (X, Y, and Z coordinates)
• Current gradient vectors in space (X, Y, and Z gradient vectors)
• Relaxed gradient vectors in space (X, Y, and Z gradient vectors)

These are called the nodal co-ordinates for this GRID.

## Format

<GRID
id        = "integer"
x         = "real"
y         = "real"
z         = "real"
rx        = "string"
ry        = "string"
rz        = "string"
x0        = "real"
y0        = "real"
z0        = "real"
rx0       = "string"
ry0       = "string"
rz0       = "string"
xd        = "real"
yd        = "real"
zd        = "real"
rxd       = "real"
ryd       = "real"
rzd       = "real"
/>

## Attributes

id
Unique GRID identification number.
x, y, z
The current X, Y, and Z position of the GRID.
x0, y0, z0
The relaxed X, Y, and Z positions of the GRID.
rx, ry, rz
The X, Y, and Z gradient vectors for the GRID. Each vector is specified as a string of three space separated values that represent the vector components.
rx0, ry0, rz0
The X, Y, and Z relaxed position gradient vectors for the GRID. Each vector is specified as a string of three space separated values that represent the vector components.
xd, yd, zd
The X, Y, and Z velocity of the grid.
Default for all three is 0.
rxd, ryd, rzd
The time of the X, Y and Z gradient vector.
Default for all three is 0.

## Example

The following is an example of a GRID defined at the origin:

<GRID id="303001" x="0.000000" y="0.000000" z="0.000000" rx="1.000000 0.000000 0.000000" ry="0.000000 1.000000 0.000000" rz="0.000000 0.000000 1.000000" />