Hi UQLab community,

I’ve meet an issue while building PCE surrogate from simulation data along a wide range of frequencies. I don’t know why UQlab crashes and/or if my data miss some informations to that end.

Please find below the UQLab report while crashing (the used script… if asked).

Is it possible to fix or to avoid this problem?

Thank you in advance,

— Calculating the PCE coefficients with least-squares. —

Warning: Warning: numerical instability!! Gamma for LAR iteration 10 was set to 0 to prevent

crashes.

In uq_lar (line 268)

In uq_PCE_lars (line 60)

In uq_PCE_calculate_coefficients_regression (line 197)

In uq_PCE_calculate_coefficients (line 47)

In uq_calculateMetamodel (line 18)

In uq_initialize_uq_metamodel (line 358)

In uq_core_module/run_initialization_script (line 208)

In uq_core_model/add_module (line 101)

In uq_createModel (line 91)

Inner matrix dimensions must agree.

Error in uq_blockwise_inverse (line 26)

SCinv = 1/(D - CAinvB);

Error in uq_lar (line 214)

M = uq_blockwise_inverse(M,x,x’,r) ;

Error in uq_PCE_lars (line 60)

lar_results = uq_lar(Psi, Y, lar_options);

Error in uq_PCE_calculate_coefficients_regression (line 197)

lars_results = uq_PCE_lars(univ_p_val, current_model);

Error in uq_PCE_calculate_coefficients (line 47)

uq_PCE_calculate_coefficients_regression(current_model);

Error in uq_calculateMetamodel (line 18)

success = uq_PCE_calculate_coefficients(current_model);

Error in uq_initialize_uq_metamodel (line 358)

success = uq_calculateMetamodel(current_model);