I did a model analysis by using PDE toolbox and obtained the solution (natural frequency; mode shape; mesh). However, I would like to get the strain from the result of the model analysis. I tried directly using the command "StrainRF=evaluateStrain(RF)", but it shows "Check for missing argument or incorrect argument data type in call to function 'evaluateStrain'." If there is any other method to get the strain from the model analysis result? I appreciate any assistance.