**Levenberg-Marquardt algorithm**In the Optimization toolbox help on the L-M method (http://www.mathworks.com/help/toolbox/optim/ug/brnoybu.html#f204)
it mentions that the "ScaleProblem" option can be used to improve the performance of a poorly scaled non-linear least squares problem by multiplying the Hessian by the lambda parameter.
Basically, I am wondering how this helps exactly. Is it a type of matrix normalization?
Any reference material which described the LM method from an engineering stand point would be greatly appreciated.
Thank you!
"LU " <g21u5@unb.removethis.ca> wrote in mes...

**Levenberg Marquardt algorithm**Hello,
I am wroking on a problem that requires me to use the levenberg
marquardt algorithm.
I am not a physics major and have never herd of any curve minimization
/ levemberg in my life before this day.
The probelem goes like this:
I have a set of points.
x - axis : Energy
y - axis : log of sensitivity
this gives me the initial curve and i make an initial guess.
i have a function f
Yt = ( ( sqr + 1) * ((1 + exp(alpha*(initialGuess - omega -
(energy))))) );
f = log(ys*(1/Yt));
This gives me another set of points based on my initial guess.
I have to minimize it.
But I have no clue of...

**bounds with levenberg-marquardt algorithm**I posted a similar question last week. I am trying to fit mass fractions using lsqcurvefit using the Levenberg-Marquardt algorithm. Since these are mass fractions, I need the values of these fi between 0 and 1, and the sum of the fi to equal 1. I have tried saying:
if sum(f) < 1
fi = [f(1) f(2) f(3) f(4) 1-sum(f)]
else
fi = [f(1) f(2) f(3) f(4) 0];
end
for n = 1:length(fi)
if fi(n) < 0
fi(n) = 0
end
end
Often, fi(n) values turn out negative, specifically, fi(5), since sum(f) > 1.
Is there a better approach to constrain these parameters (i.e., each individual mas...

**Levenberg-Marquardt algorithm #3**Hi
Does anyone know if the Levenberg-Marquardt Method uses any regularization process?
"Mar" wrote in message <l6o19g$a63$1@newscl01ah.mathworks.com>...
> Hi
>
> Does anyone know if the Levenberg-Marquardt Method uses any regularization process?
i dont think so... usually it is mentioned when a solver uses scaling (i assume you mean that). but pls note that more than one procedure use levenberg, so maybe you can be more specific. in lsqnonlin and fsolce you can scale the problem with the jacobian (see the options
...

**Modify Levenberg Marquardt algorithm**Dear All,
Could anyone kindly let me know if it is possible to modify the levenbergmarquardt.m file so that the values of the parameters being optimized can be printed to the console and modified based on a given condition during optimization? I only tried endlessly to do so via the lsqnonlin routine but to no avail.
Besides, I also wanted to find out if a complex model such as
F(x,Theta)= theta3*exp(-theta1x2) + theta4*exp(-theta2*x3) would converge for all possible randomly chosen inital conditions? I also generated the values of the x matrix using random numbers.
Any help will be gre...

**Re: Levenberg**In my previous post, I did not take into account the problem of
constraints on the parameters. The ORTHOREG procedure does not
allow one to impose parameter constraints. However, the REG
procedure allows one to RESTRICT the values of parameters.
From the description provided to this point, I believe that
the REG procedure with a RESTRICT statement is all that is
necessary to fit the model specified.
Dale
---------------------------------------
Dale McLerran
Fred Hutchinson Cancer Research Center
mailto: dmclerra@NO_SPAMfhcrc.org
Ph: (206) 667-2926
Fax: (206) 667-5977
---------------------...

**Fitting an equation to data using the Levenberg-Marquardt algorithm, with boundary constraints**Hi everyone.
I am using lsqcurvefit to fit a signalequation to some data. I am using the=
Levenberg-Marqaurdt algorithm but would really like to put some boundary c=
onstraints on the output. The most important constraint is that all the out=
put parameters are positive but I would like to constrain the values to cer=
tain ranges.=20
lsqcurvefit does not accept boundary constraints for the Levenberg-Marquard=
t algorithm, so do any of you have an idea how I can cheat lsqcurvefit to a=
ccept boundary conditions indirectly somehow or (even better): do any of yo=
u know of another i...

**SWEngr-AVP-Algorithm,2-5yrExp.in design & Development of Audio Algorithm #2**
Greetings !
Dear Sir / Madam
The following positions are needed at urgent for one of our reputed MNC
client located at Bangalore .
Order No.1
SWEngr-PDE Algorithms,2+Yr exp. inDesign&Dev.Video/Audio/ Image/Speech
CODECS.
PDE Algorithms
Name of the Position: Software Engineer
Number of Positions: 03
Qualification : ME/MTech/BE/BTech in Electrical &
Electronics/Electronics & Communication/Computer Science & Engineering.
Experience : 2 + Years of experience in design and development of
Video/Audio/Image/Speech CODECS.
Skills Required:
Designed and developed...

**2^n algorithm for textures #2**For textures with a dimension X that is not a power-of-two, what's the
best algorithm for calculating the smallest power-of-two greater than
X?
I've been using the following, but is there a simpler way?
int PowerOfTwo(int x)
{
int w = 1;
while (x != 0)
{
w <<= 1;
x >>= 1;
}
return w;
}
...

**Algorithms for X^2 and G^2 Exact Tests?**Does anyone know where I can find the SPSS algorithms for calculating
the exact Pearson X^2 and exact Loglikelihood Ratio G^2 tests? I can
find algorithms for Fisher's, but not these exact tests? In addition,
are there circumstances when these tests can not be relied upon (eg.
very low expected frequencies)?
Thanks.
On 7 Feb 2006 19:27:16 -0800, "LogReg" <mezasocool@hotmail.com> wrote:
> Does anyone know where I can find the SPSS algorithms for calculating
> the exact Pearson X^2 and exact Loglikelihood Ratio G^2 tests? I can
> find algorithms for F...

**Levenberg Marquardt**Can anyone recommend a good text that describes exactly and in detail
the Levenberg Marquardt Algorithm?
Thanks
>Richard wrote:
>
> Can anyone recommend a good text that describes exactly and
> in detail the Levenberg Marquardt Algorithm?
>
> Thanks
How about Numerical Recipes?
<http://www.library.cornell.edu/nr/bookcpdf/c15-5.pdf>
Ken
...

**Are there algorithm differences between 4.2.4 and 4.2.5?**Are there any algorithm of other differences which might cause noticeable
performance differences between 4.2.4 and 4.2.5? For example:
- 4.2.5 being more reluctant to increasing the polling interval from 64s
(with a mixture of local stratum-1 and Internet pool servers)?
- 4.2.5 showing an increased variability of offset when viewed on a
timescale of minutes?
Of course, these may just be different manifestations of the same
underlying difference.
Thanks,
David
David J Taylor has hit on an apparent regression in timekeeping
between 4.2.4 and 4.2.5. He's posted some graphs at:
...

**algorithms #2** I Would appreciate it if anyone who is knowledgable about algorithm
could point me to a good tutorial or two. Yes I could use google and come up
with all kinds of stuff but I've found the best tutorials come from those
who have experience.
I want to write a little program to print all possible combinations of
words or characters from a phone if you enter the numbers of your phone
number. For this I could use a struct, memory allocation or arrays in C. I
can study it out but I think I should be learning a few algorithms now.
I hope I am clear.
THanks,
Bill
I don't q...

**algorithm #2**
hello
I have the contour of a polygon and i want to detect the coordinates of all
"summit" (intersection of two sides).
The contour is a set of point X, Y and a set of code of Freeman (0 to 7).
How can I retrieve the coordinates (x,y) of each summit polygon. I haven't
any idea.
Thank you for your help.
Philippe
...

**ALGORITHM #2**hi all. ..i know how to calculate the sum of divisors of a number as
well know how to calculate a^b mod n;
but here question is to calculate S % mod n where S = is the sum of
divisors of a ^ b.
a and b are very large...but can fit in int range..but its
multiplication can not fit...
give me a nice algo..i m stuck frm past 6 hrs...!!!
$u!fur wrote:
> hi all. ..i know how to calculate the sum of divisors of a number as
> well know how to calculate a^b mod n;
> but here question is to calculate S % mod n where S = is the sum of
> divisors of a ^ b.
What's the meaning of ^ in yo...

**ALGORITHM #2** // MATCHCASE
// REPLACE1WITHLOREPLACE2WITH+
// REPLACE WITH2
REPLACE2P2WITH2LZ
REPLACE2NP2WITH2L0
...

**levenberg Marquardt**Hi,
I want to use the Levenberg-Marquardt algorithm to extract the best fit co-efficients for the following equation:
Y = r*((L+dL)/(W+dW))
I'm getting confused looking at the the non-linear curve fit VI. I'm not sure what to connect to the input terminals.
Input terminals: data, f(x,a), Y, X, Weight, initial coniditions, termination
My co-efficients will be = (r, dL, dW) so my initial co-efficients will be something like (500, 0, 0).
I have an array of Y values which depend on L and W so the Y input terminal is ok.
Weigh...

**SWEngr-AVP-Algorithm,2-5yrExp.in design & Development of Audio Algorithm**
Greetings !
Dear Sir / Madam
The following positions are needed at urgent for one of our reputed MNC
client located at Bangalore .
Order No.1
SWEngr-PDE Algorithms,2+Yr exp. inDesign&Dev.Video/Audio/ Image/Speech
CODECS.
PDE Algorithms
Name of the Position: Software Engineer
Number of Positions: 03
Qualification : ME/MTech/BE/BTech in Electrical &
Electronics/Electronics & Communication/Computer Science & Engineering.
Experience : 2 + Years of experience in design and development of
Video/Audio/Image/Speech CODECS.
Skills Required:
Designed and developed...

**In want know about one algorithm (k-node) and how to converted distributed algorithm for link failure?. #2**Hi to all,
My name is R.Delhi Babu. Now I am studying M.Phil (Computer
Science) in ANNA UNIVERSITY in INDIA (TAMIL NADU). I am dealing with
RELIABILITY OF DISTRIBUTED SYSTEM.
That area base on�distributed algorithm (most failure concept),
cryptography, neural network, automata.
You can suggest to any one problem give to me.
I can try to solve it.
Thanking you.
Bye
Delhi babu.R
...

**Regarding acoustic echo cancellation using frequency domain LMS algorithm and subband LMS algorithm #2**Dear all,
I am working on the acoustic echo cancellation.I have
implemented the time domain LMS algorithm for acoustic echo
cancellation and it is working fine only for some audio files and not
working for some other audio files which has the large eigen value
spread.So to avoid this eigen value spread now I am working on the
subband LMS algorithm in frequency domain for acoustic echo
cancellation.So now I am searching for the documents of subband LMS
algorithm and frequency domain LMS algorithm in which it is mentioned
clearly which samples are to be considered and why.But I ...

**SWEngr-PDE Algorithms,2+Yr exp. inDesign&Dev.Video/Audio/ Image/Speech CODECS. #2**
Greetings !
Dear Sir / Madam
The following positions are needed at urgent for one of our reputed MNC
client located at Bangalore .
Order No.1
SWEngr-PDE Algorithms,2+Yr exp. inDesign&Dev.Video/Audio/ Image/Speech
CODECS.
PDE Algorithms
Name of the Position: Software Engineer
Number of Positions: 03
Qualification : ME/MTech/BE/BTech in Electrical &
Electronics/Electronics & Communication/Computer Science & Engineering.
Experience : 2 + Years of experience in design and development of
Video/Audio/Image/Speech CODECS.
Skills Required:
Designed and developed...

**Data Structures Algorithm Analysis In CPP (3rdEd) - Weiss**
Data Structures Algorithm Analysis In CPP (3rdEd) - Weiss - Solutions
is available for purchase! Contact me at instructors.team[at]gmail.com
...

**simplex algorithm #2**Hello all.,
Iam working on simplex algorithm for a CMOS inverter circuit..
it consists of 5 cmos inverters split in 2 paths. 3 at top and 2 at
bottom
connected to same supply.i have to vary all the parameters lik W/L or
drain , source area to eqaulise the delays from both the paths at the
end of both the paths..
how do i go about it?
should i make delay times a function of some parameters i have to
vary??
Plz if anyone has some idea as to how to start in matlab, den reply
hsvjap .
...

**ECC- Algorithm #2**I am currently working in a development of error detection and
correction algorithm. I found a sample ECC algorithm provided by
Samsung for NAND flash.
Please checkup the algorithm following link.
http://www.samsung.com/Products/Semiconductor/Memory/appnote/samsung_new_ecc_for_512byte_256word.txt
The ECC algorithm detects all Single bit errors. It generates 3 ECC
(Parity code) bytes for a given data of 512bytes
We need to generate ECC codes for the original data and corrupted data.
We can generate ECC bytes using the function make_ecc_512(). Later we
need to compare them using the functio...