CALL SPRINC(S,PS,LSTR,NDI,NSHR)
S
Stress or strain tensor.
LSTR
An identifier. LSTR=1 indicates that S contains stresses; LSTR=2 indicates that S contains strains.
NDI
Number of direct components.
NSHR
Number of shear components.
PS(I), I=1,2,3
The three principal values.