Thurber.dat
NIST/ITL StRD
Dataset Name: Thurber (Thurber.dat)
File Format: ASCII
Starting Values (lines 41 to 47)
Certified Values (lines 41 to 52)
Data (lines 61 to 97)
Procedure: Nonlinear Least Squares Regression
Description: These data are the result of a NIST study involving
semiconductor electron mobility. The response
variable is a measure of electron mobility, and the
predictor variable is the natural log of the density.
Reference: Thurber, R., NIST (197?).
Semiconductor electron mobility modeling.
Data: 1 Response Variable (y = electron mobility)
1 Predictor Variable (x = log[density])
37 Observations
Higher Level of Difficulty
Observed Data
Model: Rational Class (cubic/cubic)
7 Parameters (b1 to b7)
y = (b1 + b2*x + b3*x**2 + b4*x**3) /
(1 + b5*x + b6*x**2 + b7*x**3) + e
Starting Values Certified Values
Start 1 Start 2 Parameter Standard Deviation
b1 = 1000 1300 1.2881396800E+03 4.6647963344E+00
b2 = 1000 1500 1.4910792535E+03 3.9571156086E+01
b3 = 400 500 5.8323836877E+02 2.8698696102E+01
b4 = 40 75 7.5416644291E+01 5.5675370270E+00
b5 = 0.7 1 9.6629502864E-01 3.1333340687E-02
b6 = 0.3 0.4 3.9797285797E-01 1.4984928198E-02
b7 = 0.03 0.05 4.9727297349E-02 6.5842344623E-03
Residual Sum of Squares: 5.6427082397E+03
Residual Standard Deviation: 1.3714600784E+01
Degrees of Freedom: 30
Number of Observations: 37
Data: y x
80.574E0 -3.067E0
84.248E0 -2.981E0
87.264E0 -2.921E0
87.195E0 -2.912E0
89.076E0 -2.840E0
89.608E0 -2.797E0
89.868E0 -2.702E0
90.101E0 -2.699E0
92.405E0 -2.633E0
95.854E0 -2.481E0
100.696E0 -2.363E0
101.060E0 -2.322E0
401.672E0 -1.501E0
390.724E0 -1.460E0
567.534E0 -1.274E0
635.316E0 -1.212E0
733.054E0 -1.100E0
759.087E0 -1.046E0
894.206E0 -0.915E0
990.785E0 -0.714E0
1090.109E0 -0.566E0
1080.914E0 -0.545E0
1122.643E0 -0.400E0
1178.351E0 -0.309E0
1260.531E0 -0.109E0
1273.514E0 -0.103E0
1288.339E0 0.010E0
1327.543E0 0.119E0
1353.863E0 0.377E0
1414.509E0 0.790E0
1425.208E0 0.963E0
1421.384E0 1.006E0
1442.962E0 1.115E0
1464.350E0 1.572E0
1468.705E0 1.841E0
1447.894E0 2.047E0
1457.628E0 2.200E0