from discretize import tests, utils
import numpy as np
import matplotlib.pyplot as plt
rng = np.random.default_rng(786412)
#
def simplePass(x):
    return np.sin(x), utils.sdiag(np.cos(x))
passed = tests.check_derivative(simplePass, rng.standard_normal(5), random_seed=rng)
# Expected:
## ==================== check_derivative ====================
## iter    h         |ft-f0|   |ft-f0-h*J0*dx|  Order
## ---------------------------------------------------------
##  0   1.00e-01    1.690e-01     8.400e-03      nan
##  1   1.00e-02    1.636e-02     8.703e-05      1.985
##  2   1.00e-03    1.630e-03     8.732e-07      1.999
##  3   1.00e-04    1.629e-04     8.735e-09      2.000
##  4   1.00e-05    1.629e-05     8.736e-11      2.000
##  5   1.00e-06    1.629e-06     8.736e-13      2.000
##  6   1.00e-07    1.629e-07     8.822e-15      1.996
## ========================= PASS! =========================
## Once upon a time, a happy little test passed.