The Levenberg-Marquardt method:
nonlinear systems of equations

Please select your choice here:

	Predefined BRONSTEIN n=3
	Predefined COCONUT CHEM n=5
	Predefined COCONUT I5, n=10
	Predefined BULLARD n=2
	Predefined BRANIN n=3
	Predefined MIXED ALGEBRAIC-TRIGONOMETRIC, n=3
	YOUR OWN EXAMPLE Specify the number of unknowns : n = Important: 1 <= n <=100 Please type the code for the evaluation of all components of F in the following textarea. Remember the correct line formatting: first 6 columns blank or 5 blanks and an alphanumeric character in column 6 (for a continuation line) or a numeric label in columns 1 to 5 with blank in column 6! Evaluation instructions in columns 7 to 72. Use the visible area only. Important: function components are f(1),...,f(n). Input variables are n and x, output is f. Variable names to be used are x(j), j=1,...,n. You can make use of local variables x1h,....,x9h, a vector y with 100 components, the constants pi , e1(=exp(1)) and sqrt2(=sqrt(2)). You also can use the integers i,j,k (for example for loops) and the logicals bool1,bool2,bool3. You are not allowed to define any variables yourself. x1h=x(1)**2 x2h=x(2)**2 f(1)=x1h+x2h-5.d0 f(2)=x1h-x2h-3.d0

Please specify the initial value for x here: x = (x(1),...,x(n))^T

xstart =

1,1,1

Choose the termination criteria:

	Default values
	My own choice:	termination parameter for change in x in [10-12,10-2]: xtol = termination parameter for the scaled gradient in [10-12,10-2]: gtol = termination parameter for change in ||F|| in [10-16,10-3]: ftol = the maximum number of function evaluations must be in [10*(n+1),100000] maxfev = the print frequency of the selected components of x and ||F||, must be in {0,100000}. if nprint=0 the no intermediate values are printed. nprint = The variable factor for determining the initial trust region radius, must be in [0.01,100] factor =

Warning!!! - This may take some time.

Click on "evaluate", in order to submit your input.