def dotestJvec(prb, mesh, sigma):
    prb.timeSteps = [(1e-05, 10), (0.0001, 10), (0.001, 10)]
    # d_sig = 0.8*sigma #np.random.rand(mesh.nCz)
    d_sig = 10*np.random.rand(prb.mapping.nP)
    derChk = lambda m: [prb.survey.dpred(m), lambda mx: prb.Jvec(sigma, mx)]
    return Tests.checkDerivative(derChk, sigma, plotIt=False, dx=d_sig, num=2, eps=1e-20)
dataset/ETHPy150Open simpeg/simpeg/tests/em/tdem/test_TDEM_combos.py/dotestJvec/original