""" - Open a lin file generated by OpenFAST - Perform a simple eigenvalue analysis of the A matrix (not performing MBC) - Example on how to extract submatrices of the A,B,C,D """ import os import numpy as np from pyFAST.tools.eva import eigA from pyFAST.input_output.fast_linearization_file import FASTLinearizationFile scriptDir = os.path.dirname(__file__) # --- Open lin File linFile = os.path.join(scriptDir, '../../../data/NREL5MW/5MW_Land_Lin_BladeOnly/Main.1.lin') lin = FASTLinearizationFile(linFile) print('Keys available:',lin.keys()) # --- Perform eigenvalue analysis #fd, zeta, Q, f0 = eigA(lin['A']) fd, zeta, Q, f0 = lin.eva() print('Nat. freq. [Hz], Damping ratio [%]') print(np.column_stack((np.around(f0,4),np.around(zeta*100,4)))) # --- Using dataframes instead of numpy arrays for convenient indexing of variables dfs = lin.toDataFrame() print('Dataframe available:',dfs.keys()) A = dfs['A'] print(A.columns) # --- Extract sub matrix for tower degrees of freedom #EDdof = ['qt1FA_[m]' ,'qt1SS_[m]' ,'qt2FA_[m]' ,'qt2SS_[m]'] #EDvel = ['d_qt1FA_[m/s]','d_qt1SS_[m/s]','d_qt2FA_[m/s]','d_qt2SS_[m/s]'] #print(A.loc[EDvel,EDdof]) # - M^{-1}K (stiffness) #print(A.loc[EDvel,EDvel]) # - M^{-1}D (damping) if __name__=='__main__': np.testing.assert_almost_equal(fd[:3], [0.672, 1.079,1.981],3) np.testing.assert_almost_equal(zeta[:3]*100, [0.474, 0.471,0.489],3) if __name__=='__test__': np.testing.assert_almost_equal(fd[:3], [0.672, 1.079,1.981],3) np.testing.assert_almost_equal(zeta[:3]*100, [0.474, 0.471,0.489],3)