# tensor.prin.from

Syntax

t := tensor.prin.from(l)

Get a tensor from a list containing principal values and directions.

List l must contain at least three entries.
• The first entry (index 1) is assumed to be a vector containing the principal magnitudes (x=minimum, y=intermediate, z=maximum).
• The second entry (index 2) is assumed to be a vector indicating the direction the minimum principal stress.
• The third entry (index 3) is assumed to be a vector indicating the direction of intermediate principal stress.

Any further entries are ignored.

The vectors provided do not have to be of unit length. The direction of the maximum principal stress is calculated to be orthogonal to the other two. The direction of the intermediate principal stress is corrected if necessary to be orthogonal to the minimum and maximum.

Returns: t - tensor v - list of at least three entries containing the principal value and directions.