blob: e112fbb0b8d723e21702863a4251102c724d20a6 [file] [log] [blame]
Dataset Name: Rat42 (Rat42.dat)
File Format: ASCII
Starting Values (lines 41 to 43)
Certified Values (lines 41 to 48)
Data (lines 61 to 69)
Procedure: Nonlinear Least Squares Regression
Description: This model and data are an example of fitting
sigmoidal growth curves taken from Ratkowsky (1983).
The response variable is pasture yield, and the
predictor variable is growing time.
Reference: Ratkowsky, D.A. (1983).
Nonlinear Regression Modeling.
New York, NY: Marcel Dekker, pp. 61 and 88.
Data: 1 Response (y = pasture yield)
1 Predictor (x = growing time)
9 Observations
Higher Level of Difficulty
Observed Data
Model: Exponential Class
3 Parameters (b1 to b3)
y = b1 / (1+exp[b2-b3*x]) + e
Starting Values Certified Values
Start 1 Start 2 Parameter Standard Deviation
b1 = 100 75 7.2462237576E+01 1.7340283401E+00
b2 = 1 2.5 2.6180768402E+00 8.8295217536E-02
b3 = 0.1 0.07 6.7359200066E-02 3.4465663377E-03
Residual Sum of Squares: 8.0565229338E+00
Residual Standard Deviation: 1.1587725499E+00
Degrees of Freedom: 6
Number of Observations: 9
Data: y x
8.930E0 9.000E0
10.800E0 14.000E0
18.590E0 21.000E0
22.330E0 28.000E0
39.350E0 42.000E0
56.110E0 57.000E0
61.730E0 63.000E0
64.620E0 70.000E0
67.080E0 79.000E0