1-D step-like data set

import numpy as np


def get_one_d_step():
    xt = np.array(
        [
            0.0000,
            0.4000,
            0.6000,
            0.7000,
            0.7500,
            0.7750,
            0.8000,
            0.8500,
            0.8750,
            0.9000,
            0.9250,
            0.9500,
            0.9750,
            1.0000,
            1.0250,
            1.0500,
            1.1000,
            1.2000,
            1.3000,
            1.4000,
            1.6000,
            1.8000,
            2.0000,
        ],
        dtype=np.float64,
    )
    yt = np.array(
        [
            0.0130,
            0.0130,
            0.0130,
            0.0130,
            0.0130,
            0.0130,
            0.0130,
            0.0132,
            0.0135,
            0.0140,
            0.0162,
            0.0230,
            0.0275,
            0.0310,
            0.0344,
            0.0366,
            0.0396,
            0.0410,
            0.0403,
            0.0390,
            0.0360,
            0.0350,
            0.0345,
        ],
        dtype=np.float64,
    )

    xlimits = np.array([[0.0, 2.0]])

    return xt, yt, xlimits


def plot_one_d_step(xt, yt, limits, interp):
    import matplotlib
    import numpy as np

    matplotlib.use("Agg")
    import matplotlib.pyplot as plt

    num = 500
    x = np.linspace(0.0, 2.0, num)
    y = interp.predict_values(x)[:, 0]

    plt.plot(x, y)
    plt.plot(xt, yt, "o")
    plt.xlabel("x")
    plt.ylabel("y")
    plt.show()

RMTB

from smt.examples.one_D_step.one_D_step import get_one_d_step, plot_one_d_step
from smt.surrogate_models import RMTB

xt, yt, xlimits = get_one_d_step()

interp = RMTB(
    num_ctrl_pts=100,
    xlimits=xlimits,
    nonlinear_maxiter=20,
    solver_tolerance=1e-16,
    energy_weight=1e-14,
    regularization_weight=0.0,
)
interp.set_training_values(xt, yt)
interp.train()

plot_one_d_step(xt, yt, xlimits, interp)
___________________________________________________________________________

                                   RMTB
___________________________________________________________________________

 Problem size

      # training points.        : 23

___________________________________________________________________________

 Training

   Training ...
      Pre-computing matrices ...
         Computing dof2coeff ...
         Computing dof2coeff - done. Time (sec):  0.0000000
         Initializing Hessian ...
         Initializing Hessian - done. Time (sec):  0.0000000
         Computing energy terms ...
         Computing energy terms - done. Time (sec):  0.0000000
         Computing approximation terms ...
         Computing approximation terms - done. Time (sec):  0.0000000
      Pre-computing matrices - done. Time (sec):  0.0000000
      Solving for degrees of freedom ...
         Solving initial startup problem (n=100) ...
            Solving for output 0 ...
               Iteration (num., iy, grad. norm, func.) :   0   0 1.032652876e-01 8.436300000e-03
               Iteration (num., iy, grad. norm, func.) :   0   0 6.786680863e-09 2.218151080e-13
            Solving for output 0 - done. Time (sec):  0.0000000
         Solving initial startup problem (n=100) - done. Time (sec):  0.0000000
         Solving nonlinear problem (n=100) ...
            Solving for output 0 ...
               Iteration (num., iy, grad. norm, func.) :   0   0 1.551467973e-11 2.217740430e-13
               Iteration (num., iy, grad. norm, func.) :   0   0 1.401077818e-11 2.190113743e-13
               Iteration (num., iy, grad. norm, func.) :   1   0 4.566246092e-10 1.398094006e-13
               Iteration (num., iy, grad. norm, func.) :   2   0 3.187142258e-10 9.327244974e-14
               Iteration (num., iy, grad. norm, func.) :   3   0 9.374199098e-11 2.441319143e-14
               Iteration (num., iy, grad. norm, func.) :   4   0 7.181676598e-11 1.894335409e-14
               Iteration (num., iy, grad. norm, func.) :   5   0 2.109617230e-11 1.047182645e-14
               Iteration (num., iy, grad. norm, func.) :   6   0 8.050659814e-12 9.103083561e-15
               Iteration (num., iy, grad. norm, func.) :   7   0 2.350748228e-12 8.576088440e-15
               Iteration (num., iy, grad. norm, func.) :   8   0 6.944357725e-13 8.476438536e-15
               Iteration (num., iy, grad. norm, func.) :   9   0 2.304594377e-13 8.459868871e-15
               Iteration (num., iy, grad. norm, func.) :  10   0 2.613552317e-13 8.459867906e-15
               Iteration (num., iy, grad. norm, func.) :  11   0 7.561345920e-14 8.454412587e-15
               Iteration (num., iy, grad. norm, func.) :  12   0 2.392678153e-14 8.453533882e-15
               Iteration (num., iy, grad. norm, func.) :  13   0 6.369300553e-15 8.453334168e-15
               Iteration (num., iy, grad. norm, func.) :  14   0 1.376985434e-15 8.453277655e-15
               Iteration (num., iy, grad. norm, func.) :  15   0 9.337089436e-16 8.453273240e-15
               Iteration (num., iy, grad. norm, func.) :  16   0 7.890066819e-16 8.453272942e-15
               Iteration (num., iy, grad. norm, func.) :  17   0 6.756594233e-16 8.453271528e-15
               Iteration (num., iy, grad. norm, func.) :  18   0 2.143825648e-16 8.453270718e-15
               Iteration (num., iy, grad. norm, func.) :  19   0 7.115441072e-17 8.453270419e-15
            Solving for output 0 - done. Time (sec):  0.1149590
         Solving nonlinear problem (n=100) - done. Time (sec):  0.1149590
      Solving for degrees of freedom - done. Time (sec):  0.1149590
   Training - done. Time (sec):  0.1149590
___________________________________________________________________________

 Evaluation

      # eval points. : 500

   Predicting ...
   Predicting - done. Time (sec):  0.0000000

   Prediction time/pt. (sec) :  0.0000000
../../../_images/ex_1d_step.png

RMTC

from smt.examples.one_D_step.one_D_step import get_one_d_step, plot_one_d_step
from smt.surrogate_models import RMTC

xt, yt, xlimits = get_one_d_step()

interp = RMTC(
    num_elements=40,
    xlimits=xlimits,
    nonlinear_maxiter=20,
    solver_tolerance=1e-16,
    energy_weight=1e-14,
    regularization_weight=0.0,
)
interp.set_training_values(xt, yt)
interp.train()

plot_one_d_step(xt, yt, xlimits, interp)
___________________________________________________________________________

                                   RMTC
___________________________________________________________________________

 Problem size

      # training points.        : 23

___________________________________________________________________________

 Training

   Training ...
      Pre-computing matrices ...
         Computing dof2coeff ...
         Computing dof2coeff - done. Time (sec):  0.0000000
         Initializing Hessian ...
         Initializing Hessian - done. Time (sec):  0.0000000
         Computing energy terms ...
         Computing energy terms - done. Time (sec):  0.0000000
         Computing approximation terms ...
         Computing approximation terms - done. Time (sec):  0.0000000
      Pre-computing matrices - done. Time (sec):  0.0000000
      Solving for degrees of freedom ...
         Solving initial startup problem (n=82) ...
            Solving for output 0 ...
               Iteration (num., iy, grad. norm, func.) :   0   0 1.470849329e-01 8.436300000e-03
               Iteration (num., iy, grad. norm, func.) :   0   0 1.672771647e-10 2.493685484e-14
            Solving for output 0 - done. Time (sec):  0.0166364
         Solving initial startup problem (n=82) - done. Time (sec):  0.0166364
         Solving nonlinear problem (n=82) ...
            Solving for output 0 ...
               Iteration (num., iy, grad. norm, func.) :   0   0 7.484144240e-12 2.493684372e-14
               Iteration (num., iy, grad. norm, func.) :   0   0 9.032459200e-12 2.483317928e-14
               Iteration (num., iy, grad. norm, func.) :   1   0 8.718228593e-11 2.392796282e-14
               Iteration (num., iy, grad. norm, func.) :   2   0 4.084733341e-11 1.653726244e-14
               Iteration (num., iy, grad. norm, func.) :   3   0 3.968335331e-11 1.635461268e-14
               Iteration (num., iy, grad. norm, func.) :   4   0 1.075192906e-11 1.163951275e-14
               Iteration (num., iy, grad. norm, func.) :   5   0 2.996703771e-12 1.114623030e-14
               Iteration (num., iy, grad. norm, func.) :   6   0 4.613969124e-13 1.109347169e-14
               Iteration (num., iy, grad. norm, func.) :   7   0 9.192134677e-14 1.109036961e-14
               Iteration (num., iy, grad. norm, func.) :   8   0 5.561355733e-14 1.108986678e-14
               Iteration (num., iy, grad. norm, func.) :   9   0 1.518497445e-14 1.108946807e-14
               Iteration (num., iy, grad. norm, func.) :  10   0 3.525949088e-15 1.108940914e-14
               Iteration (num., iy, grad. norm, func.) :  11   0 4.977597964e-16 1.108940364e-14
               Iteration (num., iy, grad. norm, func.) :  12   0 4.328767946e-17 1.108940341e-14
            Solving for output 0 - done. Time (sec):  0.0814357
         Solving nonlinear problem (n=82) - done. Time (sec):  0.0814357
      Solving for degrees of freedom - done. Time (sec):  0.0980721
   Training - done. Time (sec):  0.0980721
___________________________________________________________________________

 Evaluation

      # eval points. : 500

   Predicting ...
   Predicting - done. Time (sec):  0.0000000

   Prediction time/pt. (sec) :  0.0000000
../../../_images/ex_1d_step.png