features.py

computeFeatures_torch(I1, I2, I3):

Transforms the three principal invariants of the Cauchy-Green deformation tensor into mixed-deviatoric-volumetric invariants and returns them in a concatenated array.

• $J=det(\mathbf{F})=I_3^{1/2}$
• $\widetilde{I_1}=J^{-2/3}{I}_1$
• $\widetilde{I_2}=J^{-4/3}{I}_2$

Input Arguments

• I1 - 1st invariant

• I2 - 2nd invariant

• I3 - 3rd invariant

Output Arguments

• x - $[\widetilde{I_1},\widetilde{I_2},J]$

getNumberOfFeatures():

Compute number of features.

Input Arguments

• none

Output Arguments

• features.shape[1] - number of features

---