safety_factor_fit.py 文件源码

def default1():
    numRadialPts = 144;
    rhoMin = 0.1
    rhoMax = 0.9
    rho = np.linspace(rhoMin, rhoMax, numRadialPts);
    qbar = 0.854 + 2.184 * rho**2;

    minorRadius = 0.28;  # a
    majorRadius = 0.71;  # R0
    r = rho * minorRadius;
    safetyFactor = qbar / np.sqrt(1 - (r/majorRadius)**2);

    # fit
    polynomialDegree = 3;
    p = np.polyfit(rho, safetyFactor, polynomialDegree)
    qCoeffs = p[::-1]
    return qCoeffs