ru.algorithms

 
 - RU.ALGORITHMS ----------------------------------------------------------------
 From : Alex Astafiev                        2:5000/228.16  09 Dec 2002  22:47:02
 To : All
 Subject : Levenberg-Marquardt NonLinearFit
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 Разыскиваю алгоритм (реализацию, имплементацию) следующей функции:
 int status = NonLinearFit (double x[], double y[], double z[], int n, ModelFun
 *modelFunction, double a[], int ncoef, double *mse);
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 Purpose
 
 Uses the Levenberg-Marquardt algorithm to determine the least squares set of
 coefficients that best fit the set of input data points (x, y) as expressed by
 a nonlinear function y = f(x, a) where a is the set of coefficients.
 NonLinearFit also gives the best fit curve y = f(x, a).
 
 You must pass a pointer to the nonlinear function f(x, a) along with a set of
 initial guess coefficients a. NonLinearFit does not always give the correct
 answer. The correct output sometimes depends on the initial choice of a. It is
 very important to verify the final result.
 
 Parameters
 
 Input
 
 Name Type Description
 x    double-precision
 array     Array of x-coordinates of the (x, y) data sets to fit.
 y    double-precision
 array     Array of y-coordinates of the (x, y) data sets to fit.
 n    integer   Number of elements in both the x and y arrays.
 modelFunction  ModelFun  Pointer to the model function, f(, a), used in the
 nonlinear fitting algorithm. The model function must be defined as follows:
 double ModelFunct
 (double x, double a[],
 int ncoef);
 where a contains the function coefficients.
 a    double-precision
 array     On input, a gives a set of initial guess coefficients.
 ncoef     integer   Number of coefficients (size of a).
 Output
 
 Name Type Description
 z    double-precision
 array     Best fit array, y = f(x, a).
 a    double-precision
 array     Best fit coefficients.
 mse  double-precision    Mean squared error between y and z.
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  * Origin: Фидонет - сеть друзей. Будьте дружественнее! (2:5000/228.16)
 
 

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