Hi, everybody

I am trying to fit a system of ordinary differential equations (kinetics model)
to experimental data to work out the best-fit parameter values. Levenberg-Marquardt method
might solve this problem. Does any one know where I can get the existing code in Fortran
for Levenberg-Marquardt method to be used in my case?

The one in Mumerical Recipes seems not suitable for my problem.

Thanks a lot.

Wei

Hello everyone!

My name is Slimane TAHI. I'm a researcher at the university
of Algiers and I encouter hard difficulties,in Algeria, to get
documents on my research field (no reviews and journals in my University
library, no Current Contents or similar bulletin and no coupons
to get copies from European or American documents delivery
services...).

I Would constitute in my laboratory a bibliographical fund to
facilitate for searchers and graduate students the access to
knowledge in my field of interest: magnetic field in electrical
machines in general magnetic field calculation
using numerical methods in particular.

At the present time , my field of interest is reluctance machine
(High Speed Synchronous Machine, Switched Reluctance Machine ..)

To do this , I need a software package if possible with source code
suitable to electrical engineering (axisymmetric 2D problems for instance)
or any document you think valuable.

Please send your message at this email adress :
s_tahi@hotmail.com
or,

usthbits3@ist.cerist.dz

with my thanks

Hi netlibers,

Does anybody know where can i find a program of Partial
Least Square(PLS)?

Thanks in advance.

In Reply to: Levenberg Marquardt Method posted by Wei Zhang on September 09, 1998 at 03:30:14:

: Hi, everybody

: I am trying to fit a system of ordinary differential equations (kinetics model)
: to experimental data to work out the best-fit parameter values. Levenberg-Marquardt method
: might solve this problem. Does any one know where I can get the existing code in Fortran
: for Levenberg-Marquardt method to be used in my case?

: The one in Mumerical Recipes seems not suitable for my problem.

: Thanks a lot.

: Wei.

MINPACK contains implementations of this method.

However, for more complete information, I recommend
you go to:
http://gams.nist.gov/

Then choose "problem decision tree". You will find
MINPACK (among others) located under subclass K
(specifically, branch: K1b1a1).

Good luck,
A fellow physical chemist

Hello,

I am interested in getting the math library that we can
use in our C programs. For example, we would need functions
for calculating Fourier Transforms, random number generator,
statistics etc.

Is NetLib place where I could get different computational
routines as separate pieces or I can get the whole C library?

Are you aware of any commercial/non-commercial package that
would feet my needs?

Thanks a lot in advance,
Adnan

When I use IMDIF in MINPACK, I find it very sensitive to the initial guess. Are there some ways to deal with it? Thanks a lot!

Does anyone have:

1.) A C routine for doing a Bessel interpolation?

2.) An algorithm for working a Bessel function of the first kind backwards? That is given:

y = Jn(x), y and n known

what are the possible values of x? I have already determined that if you compare 2 different orders, such as J0(x) and J1(x) you will get a unique answer, but what is the easiest way to do this?

DOES ANY ONE KNOW WHERE I COULD FIND PROGRAM CODE IN C FOR BASIC LINEAR ALGEBRA COMPUTATIONS?

Hello,

I have a simple eigenvalue problem
[A-kI]x = 0
A is non-symmetric but invertible and block tri-diagonal.
k is a scalar, I is the identity matrix, and x is a vector.

I'd like to obtain the lower eigenvalues (lower 10%) of A, and I presume the Lanczos method would be most appropriate. A is large (size varies depending on the problem), so utilizing the tri-diagonal structure is important. Is there a Netlib routine to handle this problem? Do I need to do some kind of transform on A?

Thanks,
Jonathan French
jfrench@ticnet.com

(In response to my previous post:)
ARPACK uses LAPACK routines, and determines the eigenvalues of non-symmetric banded matrices.
Jon French

Hello everybody,

I would like to solve a problem using C or C++ codes of Yale Sparse Matrix Package.
But I can't find the codes.
If possible, could you let me know where I can get the source codes.

Thanks in advance,
Dongryeol Kim.

Hi everybody,
I want to get a program (software) to optimize
a HIGHLY NONLINEAR MULTIVARIATE objective
function with LINEAR CONSTRAINTS.

I will appreciate anybody's help

Thank you,

A K Datta

I am looking for software (preferably in C) which
computes the error function erf(z) for z complex.

The definition is:

erf(z)= integral(exp(-w^2), w=0..z)

or in words: The integral from 0 to z of the exponential of -(w^2). This is a contour integral in the complex plane, but since the integrand is
a holomorphic function, the answer is independent of the path. A possible path is the line from 0 to z.

I am looking for a program that calculates non-product quadrature weigths and absisas for 2D box numerical integrals. Preferably of the Jenkins type.

Thank you

Hello:

Can anybody tell me where I can get a finite element matrix assembly code in c/c++?

Thanks alot!

Hi,
Does anybody know where I can get source code or algorithm to fit an ellipse or circle to a set of datas in 3D space using least squars method? Thanks.

Hi, everybody. Anybody knows where can I get free software for computer simulation?

Thanks

I am looking for software written C++ to compute confluent hypergeometric functions with complex argument. Is there an existing library that I can purchase or download?

hi everybody,
i am searching for a source code in c or c++
for viewing a BMP or JPEG image .
if anybody has any idea where i can get one
please write to ameyb@giasbma.vsnl.net.in

Hello,

I am trying to find some software that will solve a system of nonlinear, algebraic eq'ns with a major stipulation being that one of the variables must be an integer. The other(s) can be any real number. Does anyone know of any software with this option? It would be very helpful. Thank you very much. Feel free to e-mail me if you know.

--Jack

Hi again,

As a follow up to my last post: I realize that holding one of the vars to being an integer would cause there to be, in most cases, no solution. So I guess what I really want to know is if anyone knows of any optimization software that won't solve the system per say, but find the best set of vars. Thanks a lot.

--Jack johnp.smith@ps.ge.com

Hi, does anyone know the algorithm used by passport readers?

Thank you!
bill_allen9@hotmail.com

My question concerns the use of preconditioned conjugate gradient as a baseline smoother for an algebraic multigrid method (ILU0 preconditioning is used). During the prolongation pass of a V cycle implementation, the fine grid solution is constantly corrected as the method moves from the coarsest to finest grid. Are there any additional parameters that need to be updated in conjunction with the fine grid solution in order for ICCG to work properly? For example, do the search vectors need to modified?

Thanx,
Steve

Hi Softies:


I need arbitrary-precision arithmetic software so I could greatly extend FORTRAN's REAL*8 (or REAL*16) and C's double (or long double).


Thanks,


Joseph Roy North
E: joseph_north@hotmail.com

HI,

I m looking for a software that could compute a 2000 by 2000 random dense non symetric matrix.

I m currently using the matrix generator from the lapack test suite but it only provides 200 by 200 matrices.

Thanks

Manuel Capouet

Hi,

I'm looking for sparse matrix diagonalization

routine. Could you please give me a hint on where

I can find it.


Thanks in advance, student

Has anyone done partial fraction
expansions in Fortran ?

Nils

I'm trying to solve a generalized eigenvalue problem
K x = Lambda M x, where M and K are symmetric,
and I want only some eigenvalues and eigenvectors,
not all.

Can someone tell me where to find such FORTRAN
subroutines ?

i need to modify the fortran routine poisnd2.f (downloaded from the netlib fishpack directory), to find a solution to poisson equation:

Uxx + Uyy = F(x,y) for 0<=x,y<= 1.
with u=0 on the boundary. here u(x,y) represents the deflection of an elastic membrane under a load f(x,y). any suggestions? pls help ASAP.

Does anyone know where I can get a Visual Basic program for the Levenberg-Marquardt method?

Hi,
I'm looking for a sparse symmetric linear solver implemented in java to solve a system arising from a plain vanilla linear elasticity FEM problem. It doesn't make a difference whether direct or iterative as long as just does the job.

Any suggestions?

Regards,

Robert

Hello,

I am looking for a program to compute the generalized hypergeometric function 2F1.

Regards,

Emmanuel

Hy, my name is Gianluca
Do you know where can I find algorithms/software
for a multidimensional inverse Laplace transform?

Regards
gianluca

Hello. I have a dense symmetric 1500x1500 matrix, and I am looking for a library (FORTRAN or C++) that can help me solving the following problems:

Find determinant.
Find number of negative eigenvalues

If I find the matrix interesting it would be nice to be able to continue in the following way.

Find the 3 lowest eigenvalues.
or
Find the 3 lowest eigenvalues and eigenvectors

I have been pointed to Bunch Parlett decomposition (and Sylvesters theorem), but I am not sure if this is useful, because BPD only gives me the signs of the eigenvalues.

I have also been pointed to Arpack, but it seems that Arpack is best at sparse matrixes.

Thanks in advance for any help

HI, every body. I am student from Indonesia.
I am looking for subroutine for generalized eigen problem (K.x = Lambda.M.x) based on Lanczos Algorithma.
Thanks in advance

Can someone suggest where can I find an implementation of the nl2sol algorithm in C?

Please email to hnk5@yahoo.com

Dear sirs;

A high efficient solver for the singly bordered triangular band matices is needed in an unsteady flow computations in which the matrices elements would change.

sincerely yours;

Elsamni, Osama

Hi !

I'm looking for a method/algorithm which evaluates the number of minima of a function, using only sparse samples of it.

Does anyone know if such an algo exists?

Many Thanks

agathe

Levenberg-Marquardt Method

I have used the Marquardt method to fit data to a function. The implementation is from Numerical Recipies in C. The problem is that I keep getting stuck in local minima.

I've tried the same method in mathcad, which works by adding small random amounts to the varables. This works, therefore I'm hoping that someone out there has a similar implementation (modifying the algorithm) that avoids these minima.

also which convergence criteria do people generally use?

Thanks for any help
Graeme

Hi every body
I'm looking for a software that can make simple manipulations on sparse matrix.
I would like a sofware that was tested under Visual C++

I've tried to use the numerical recipies routine to fit data to a nonlinear eqn of 2 variables but I've been informed that this algorithm is useless. Therefore I've decided to use minpack, as mathcad does, but I can't seem to figure out the arguments to various routines.
essentially I have
X - an array of x measured data points
Y - an array of y measured data points
nu, peakpos - first guess for variables of theoretical eqn fitting Y

I reckon I have to use either

hybrd1(fcn,n,x,fvec,tol,info,wa,lwa)
or
lmder(fcn,m,n,x,fvec,fjac,ldfjac,ftol,xtol,gtol,maxfev,diag,mode,factor,nprint,info,nfev,njev,ipvt,qtf,wa1,wa2,wa3,wa4)

the problem is that I can't figure out how to pass the routines the experimental data, get the value of chi_sqrd or figure out what most of the arguments mean.
The documentation is quite difficult to figure out, so I need an idiots guide

can someone please, please help
I've spent far far too long on this problem and it's driving me mad.

thanks
Graeme

Hi everybody

What is the best definition of the following square matrix (say 8x8)

d e f g h i j k
c d e f g h i j
b c d e f g h i
a b c d e f g h
0 a b c d e f g
0 0 a b c d e f
0 0 0 a b c d e
0 0 0 0 a b c d

If you have quick and efficient solver for such kind of matrices (preferably in Fortran), please kindly send me.

Yours
Osama El-Samni

Hello,

I'm looking for a Fortran routine (preferably public-domain, or a description of how to write one) that computes contours of elevation. So far I have only found high-level routines that include the actual. I only want the contour lines as output (cf. 'contourc' in Matlab). Please respond to my email address.

TIA,

Olof Liungman
Swedish Meteorological and Hydrological Institute

CFFTMLT.F and RFFTMLT.F

... is this source code available anywhere?

Hi there,

I am trying to estimate the parameters of a system of nonlinear ordinary differential equations (stiff problem, cell cycle model) by fitting experimental data. These parameters have some constraints. Hence, it should be a problem of nonlinear least square with nonlinear contraints. Does anyone can give me a guide which existing codes are can be used to solve this problem?

Thank you very much in advance. Look forward to getting some suggestions from you soon.


Jim

Hi everyone,

I am looking for a c/C++ routine that computes the Eigenvalues and Eigenvectors of a matrix. Maybe the same as EIG in Matlab.

Please email me at jerbianis@hotmail.com with any suggestions.
Thanx in advance.

Akram Jerbi

Hi all,

I'm looking for java source code to a simplex method. Does anyone know where I can get ahold of it?

Shay Capehart
shay.capehart@afit.af.mil

Hi all,

I'm looking for java source code to a simplex method. Does anyone know where I can get ahold of it?

Shay Capehart
shay.capehart@afit.af.mil

Hi all,

I'm looking for java source code to a simplex method. Does anyone know where I can get ahold of it?

Shay Capehart
shay.capehart@afit.af.mil

I'm looking for a conjugent gradient minimizatin routine in C/C++ (multivariate). Everything I find is in fortran. Is there one on here hiding somewhere? Or can someone point me in the right direction. Thanks for the help.

David
stucke@phys.psu.edu

I'm looking for a conjugent gradient minimizatin routine in C/C++ (multivariate). Everything I find is in fortran. Is there one on here hiding somewhere? Or can someone point me in the right direction. Thanks for the help.

David
stucke@phys.psu.edu

MARQUARDT in C++?????
Hello,

does anybody know, where to get a stabil implementation of the Maruqardt-Levenberg-
Optimization, written in C/C++? The implementation
in NumRecip does not solve my problem.

Thanks a lot!!!

MARQUARDT in C++?????
Hello,

does anybody know, where to get a stabil implementation of the Maruqardt-Levenberg-
Optimization, written in C/C++? The implementation
in NumRecip does not solve my problem.

Thanks a lot!!!

I am looking for a subroutine in FORTRAN to implement neural networks based on backpropagation method. Does anyone knows any ?

I am looking for something similar to FISHPAK but coded in C or C++. I need a C/C++ library that can solve finite differences problems like those encountered in fluid dynamics (Navier-Stokes) and Newtonian mechanics. Please drop me a line if you know of anything. Thanks!

I am looking for an algorithm (preferably in FORTRAN) to calculate the inverse of a 3x3x3x3 fourth rank tensor. Are there any references regarding the transformation of fourth rank tensors into second rank tensors, determinaion of the inverse of the second rank tensors, and then transformion back to fourth rank tensors?

Hi, I need library in C++ for reading and writing a bitmap (bmp) or just send me website address
Thank you.