Hi,Edward: I have already used the program relax 2.2.5 to run through all diffusion model: Sphere, Prolate, Oblate and Ellipsoid in a uni-processor and obtained the converged fitting results that passed the convergence test. However, I stuck on the "final" mode because of some errors as shown below: relax> value.set(val=-0.00017199999999999998, param='csa', spin_id='@N') relax> pipe.create(pipe_name='local_tm - mf', pipe_type='mf', bundle='mf') relax> results.read(file='results', dir='C:\\relax\\ Model Free Analysis\\local_tm\\aic') Opening the file 'C:\\relax\\Model Free Analysis \\local_tm\\aic\\results.bz2' for reading. relax> pipe.create(pipe_name='sphere - mf', pipe_type='mf', bundle='mf') relax> results.read(file='results', dir='C:\\relax\\Model Free Analysis \\sphere\\round_13\\opt') Opening the file 'C:\\relax\\Model Free Analysis \\sphere\\round_13\\opt\\results.bz2' for reading. relax> pipe.create(pipe_name='prolate – mf', pipe_type='mf', bundle='mf') relax> results.read(file='results', dir='C:\\relax\\Model Free Analysis \\prolate\\round_123\\opt') Opening the file 'C:\\relax\\Model FreeAnalysis \\prolate\\round_123\\opt\\results.bz2' for reading. relax> pipe.create(pipe_name='oblate - mf', pipe_type='mf', bundle='mf') relax> results.read(file='results', dir='C:\\relax\\ Model Free Analysis\\oblate\\round_14\\opt') Opening the file 'C:\\relax\\Model Free Analysis \\oblate\\round_14\\opt\\results.bz2' for reading. relax> pipe.create(pipe_name='ellipsoid - mf', pipe_type='mf', bundle='mf') relax> results.read(file='results', dir='C:\\relax\\Model Free Analysis \\ellipsoid\\round_912\\opt') Opening the file 'C:\\relax\\Model Free Analysis \\ellipsoid\\round_912\\opt\\results.bz2' for reading. relax> model_selection(method='AIC', modsel_pipe='final - mf', bundle='mf', pipes=['local_tm - mf ', 'sphere - mf', 'prolate - mf', 'oblate - mf', 'ellipsoid - mf ']) AIC model selection. Global model - all diffusion tensor parameters and spin specific model-free parameters. # Data pipe Num_params_(k) Num_data_sets_(n) Chi2 Criterion local_tm - mf (Mon Aug 19 22:40:08 2013) 323 696 5983.71348 6629.71348 sphere - mf (Mon Aug 19 22:40:08 2013) 237 696 6374.27910 6848.27910 prolate - mf (Mon Aug 19 22:40:08 2013) 232 696 6209.77670 6673.77670 oblate - mf (Mon Aug 19 22:40:08 2013) 235 696 6274.97999 6744.97999 ellipsoid - mf (Mon Aug 19 22:40:08 2013) 238 696 6184.98839 6660.98839 The model from the data pipe 'local_tm - mf' has been selected. relax> monte_carlo.setup(number=500) relax> monte_carlo.create_data(method='back_calc') RelaxError: The specific model has not been selected or set up. Do you have any idea what is wrong in the here? Thanks Jing