Computation results are unstable for model within high frequency range

[xichaoqiang]

I encountered unstable results when running the following model. The output fluctuates unexpectedly or shows numerical artifacts.

import numpy as np
import Array

model_file = "model/Test1.dat"
output_file = "model/Test1.resp"

model = Array.io.read_model_file(model_file)

freq_sim,resp_sim = Array.analysis.model_medium_response_py(model,fmax=92,nmode=1,print_flag=True,plot_flag=True)

Array.io.output_pv_file(output_file,freq_sim,resp_sim)

Test1.dat

# number of layers
4
# vs[m/s], vp[m/s], rho[kg/m3], depth[m]
300 700 1800 15
400 900 1900 30
500 1100 2000 45
600 1300 2100