This is the repository to generate response functions of 2d active material from their displacement fields as described in the manuscript “Measuring response functions of active materials.” The code “StrainField.m '' calculates shear response and the code “VorticalField.m '' calculates the vortical response.
The codes read the displacement fields measured by different techniques. The displacement field should be stored in the following format:
flowField(frames).uv(:,:,1)=velocity in x direction flowField(frames).uv(:,:,2)=velocity in y direction
First run “Lambda_OverGrids.m” as instructed in the code to generate the local gradient of the displacement field and its eigenvalues and eigenvectors. The code will save the result in a file with a name assigned by the user. Then run “StrainField.m''. Choose the name of the “filename_lambda” as the name of the file generated by the “Lambda_OverGrids.m”.