               NEWS NLREG has been selected as the "Editor"s Pick" by SoftSeek. NLREG is in use at hundreds of universities, laboratories, and government agencies around the world (over 20 countries). For a list of a few organizations using NLREG click here. If you have categorical variables, you may want to use a Decision Tree to model your data. Check out the DTREG Decision Tree Builder. You also should check out the News Rover program that automatically scans Usenet newsgroups, downloads messages of interest to you, decodes binary file attachments, reconstructs files split across multiple messages, and eliminates spam and duplicate files.  ## NIST - Misra1a Dataset

```   1: /*
2:  * Statistical Reference Datasets  (Nonlinear Regression)
3:  * Statistical Engineering Division
4:  * National Institute of Standards and Technology
5:  * http://www.nist.gov/itl/div898/strd/
6:  *
7:  * Dataset: Misra1a
8:  *
9:  * Description:  These data are the result of a NIST study regarding
10:  *               dental research in monomolecular adsorption.  The
11:  *               response variable is volume, and the predictor
12:  *               variable is pressure.
13:  *
14:  * Reference:    Misra, D., NIST (1978).
15:  *               Dental Research Monomolecular Adsorption Study.
16:  * Data:         1 Response Variable  (y = volume)
17:  *               1 Predictor Variable (x = pressure)
18:  *               14 Observations
19:  *               Lower Level of Difficulty
20:  *
21:  * Model:        Exponential Class
22:  *               2 Parameters (b1 and b2)
23:  *
24:  *               y = b1*(1-exp[-b2*x])  +  e
25:  *
26:  *           Starting values                  Certified Values
27:  *
28:  *          Start 1   Start 2       Parameter         Standard Deviation
29:  *   b1 =    500         250     2.3894212918E+02      2.7070075241E+00
30:  *   b2 =    0.0001    0.0005   5.5015643181E-04       7.2668688436E-06
31:  *
32:  *   Residual Sum of Squares:                   1.2455138894E-01
33:  *   Residual Standard Deviation:               1.0187876330E-01
34:  *   Degrees of Freedom:                        12
35:  *   Number of Observations:                    14
36:  */
37:
38: Title "Misra1a";
39: variables y,x;
40: parameter b1=500;
41: parameter b2 = 0.0001;
42: function y = b1*(1-exp(-b2*x));
43: plot;
44: data;

Beginning computation...
Stopped due to: Relative function convergence.

----  Final Results  ----

NLREG version 4.0
This is a registered copy of NLREG that may not be redistributed.

Misra1a
Number of observations = 14
Maximum allowed number of iterations = 500
Convergence tolerance factor = 1.000000E-010
Stopped due to: Relative function convergence.
Number of iterations performed = 16
Final sum of squared deviations = 1.2455139E-001
Final sum of deviations = 2.5418397E-001
Standard error of estimate = 0.101879
Average deviation = 0.0905298
Maximum deviation for any observation = 0.131916
Proportion of variance explained (R^2) = 1.0000  (100.00%)
Adjusted coefficient of multiple determination (Ra^2) = 1.0000  (100.00%)
Durbin-Watson test for autocorrelation = 0.561
This Durbin-Watson value indicates autocorrelation or inappropriate function.

----  Descriptive Statistics for Variables  ----

Variable    Minimum value   Maximum value    Mean value     Standard dev.
----------  --------------  --------------  --------------  --------------
y           10.07           81.78        43.34071        22.80652
x            77.6             760           375.4        216.0569

----  Calculated Parameter Values  ----

Parameter  Initial guess   Final estimate   Standard error      t      Prob(t)
----------  -------------  ----------------  --------------  ---------  -------
b1            500        238.942129        2.707008      88.27  0.00001
b2         0.0001    0.000550156432   7.266869E-006      75.71  0.00001

----  Analysis of Variance  ----

Source     DF   Sum of Squares    Mean Square    F value   Prob(F)
----------  ----  --------------  --------------  ---------  -------
Regression     1        6761.663        6761.663  651457.69  0.00001
Error         12       0.1245514      0.01037928
Total         13        6761.788
```