| A_x_B | A Kronecker product B |
| check_periodicity | Checking the periodicity of parameters in the regression model |
| DELTA | Calculating the component of vector DELTA |
| estimate_para_adaptive_method | Adaptive estimator for periodic coefficients regression model |
| GAMMA | Calculating the component of matrix GAMMA |
| lm_per | Fitting periodic coefficients regression model by using LSE |
| lm_per_AE | Fitting periodic coefficients regression model by using Adaptive estimation method |
| LSE_Reg_per | Least squares estimator for periodic coefficients regression model |
| phi_n | Calculating the value of phi function |
| pseudo_gaussian_test | Detecting periodicity of parameters in the regression model |
| sd_estimation_for_each_s | Estimating periodic variances in a periodic coefficients regression model |