/* NIST/ITL StRD Dataset Name: Eckerle4 (Eckerle4.dat) File Format: ASCII Starting Values (lines 41 to 43) Certified Values (lines 41 to 48) Data (lines 61 to 95) Procedure: Nonlinear Least Squares Regression Description: These data are the result of a NIST study involving circular interference transmittance. The response variable is transmittance, and the predictor variable is wavelength. Reference: Eckerle, K., NIST (197?). Circular Interference Transmittance Study. Data: 1 Response Variable (y = transmittance) 1 Predictor Variable (x = wavelength) 35 Observations Higher Level of Difficulty Observed Data Model: Exponential Class 3 Parameters (b1 to b3) y = (b1/b2) * exp[-0.5*((x-b3)/b2)**2] + e Starting values Certified Values Start 1 Start 2 Parameter Standard Deviation b1 = 1 1.5 1.5543827178E+00 1.5408051163E-02 b2 = 10 5 4.0888321754E+00 4.6803020753E-02 b3 = 500 450 4.5154121844E+02 4.6800518816E-02 Residual Sum of Squares: 1.4635887487E-03 Residual Standard Deviation: 6.7629245447E-03 Degrees of Freedom: 32 Number of Observations: 35 */ clear scalar N = 35 scalar df_r = 32 scalar df_m = 3 scalar rss = 1.4635887487E-03 scalar rmse = 6.7629245447E-03 scalar b1 = 1.5543827178E+00 scalar seb1 = 1.5408051163E-02 scalar b2 = 4.0888321754E+00 scalar seb2 = 4.6803020753E-02 scalar b3 = 4.5154121844E+02 scalar seb3 = 4.6800518816E-02 qui input double(y x) 0.0001575E0 400.000000E0 0.0001699E0 405.000000E0 0.0002350E0 410.000000E0 0.0003102E0 415.000000E0 0.0004917E0 420.000000E0 0.0008710E0 425.000000E0 0.0017418E0 430.000000E0 0.0046400E0 435.000000E0 0.0065895E0 436.500000E0 0.0097302E0 438.000000E0 0.0149002E0 439.500000E0 0.0237310E0 441.000000E0 0.0401683E0 442.500000E0 0.0712559E0 444.000000E0 0.1264458E0 445.500000E0 0.2073413E0 447.000000E0 0.2902366E0 448.500000E0 0.3445623E0 450.000000E0 0.3698049E0 451.500000E0 0.3668534E0 453.000000E0 0.3106727E0 454.500000E0 0.2078154E0 456.000000E0 0.1164354E0 457.500000E0 0.0616764E0 459.000000E0 0.0337200E0 460.500000E0 0.0194023E0 462.000000E0 0.0117831E0 463.500000E0 0.0074357E0 465.000000E0 0.0022732E0 470.000000E0 0.0008800E0 475.000000E0 0.0004579E0 480.000000E0 0.0002345E0 485.000000E0 0.0001586E0 490.000000E0 0.0001143E0 495.000000E0 0.0000710E0 500.000000E0 end /* The following starting values led to convergence problems: nl ( y = ({b1}/{b2}) * exp(-0.5*((x-{b3})/{b2})^2) ), /// init(b1 1 b2 10 b3 500) eps(1e-10) */ nl ( y = ({b1}/{b2}) * exp(-0.5*((x-{b3})/{b2})^2) ), /// init(b1 1.5 b2 5 b3 450) eps(1e-10) assert N == e(N) assert df_r == e(df_r) assert df_m == e(df_m) lrecomp [b1]_b[_cons] b1 [b2]_b[_cons] b2 [b3]_b[_cons] b3 () /* */ [b1]_se[_cons] seb1 [b2]_se[_cons] seb2 [b3]_se[_cons] seb3 () /* */ e(rmse) rmse e(rss) rss