Displaying 18 results from an estimated 18 matches for "lagrangian".
2008 Jul 07
3
subset() multiple arguments
This is what I would like to do and it works just fine. Is there a way to
shorten this code so I don't have to subset a subset of a subset?
d<-subset(subset(subset(subset(x, River.Mile<=202), River.Mile>3),
Lagrangian=="Yes"), EventType=="Regular")
Stephen
--
Let's not spend our time and resources thinking about things that are so
little or so large that all they really do for us is puff us up and make us
feel like gods. We are mammals, and have not exhausted the annoying little
problem...
2009 Mar 17
3
Non-Linear Optimization - Query
Dear All,
I couple of weeks ago, I’ve asked for a package recommendation for nonlinear
optimization. In my problem I have a fairly complicated non-linear objective
function subject to one non-linear equality constrain.
I’ve been suggested to use the *Rdonlp2* package, but I did not get any
results after running the program for 5 hrs. Is it normal to run this type
of programs for hours? Also,
2011 May 18
1
Constrainted Nonlinear Optimization - lack of convergence
..., all other z
constraints are z=0, and the Z - sum(z) > 0 inequality constraint. I used
default settings, except for attempts to utilize various 'methods', e.g.
BFGS, Nelder-Mead.
Review of the alamaba package source code leads me to believe that this code
automatically generates the Lagrangian of the cost function augmented with
Lagrangian multipliers, and also generates the gradient of the augmented
Lagrangian. Hence, I assume (perhaps incorrectly), that auglag is
automatically generating the dual problem, and attempts to find a solution
to the dual problem by calling 'optim'....
2005 Feb 11
1
Help concerning Lasso::l1ce
...ntercept) lcavol lweight age
lbph svi
1.0435803 0.4740831 0.1953156 0.0000000
0.0000000 0.3758199
lcp gleason pgg45
0.0000000 0.0000000 0.0000000
The relative L1 bound was : 0.44
The absolute L1 bound was : 0.8113534
The Lagrangian for the bound is: 17.89198
And the sum of the absolute values of the coefficients
are larger than the bound!! Why?
Second, the manual says that if I set sweep.out to
NULL, the constant term (which is the intercept,
right?)
will be included in the bound, but when I do so, I get
an error "Mat...
2009 Nov 04
3
Constrained Optimization
Hi All,
I'm trying to do the following constrained optimization example.
Maximize x1*(1-x1) + x2*(1-x2) + x3*(1-x3)
s.t. x1 + x2 + x3 = 1
x1 >= 0 and x1 <= 1
x2 >= 0 and x2 <= 1
x3 >= 0 and x3 <= 1
which are the constraints.
I'm expecting the answer x1=x2=x3 = 1/3.
I tried the "constrOptim" function in R and I'm running into some issues.
I first start off
2009 Jul 03
2
Error using the Rdonlp2 Package
Dear experts,
I'm attempting to solve a constrained optimization problem using the Rdonlp2
package.
I created a Lagrange function (L=f(x)-lambda(g(x)-c)), where x is a vector
of 16 parameters. This is what I'm using as objective function in the code
below. In addition, I set bounds on these parameters (par.u and par.l). When
I run the code, I get the error message shown below. Any idea
2010 Jul 07
4
constrained optimization
Dear list,
The task view on optimization does not reference a package for non linear
constrained optimization problems. Stefan Theussl told me to look at the
Rsolnp package, but unfortunately it is not very clear what method is R
ported. (The authors ported the matlab code of Yinyu Ye
http://www.stanford.edu/~yyye/ <http://www.stanford.edu/%7Eyyye/>)
Currently I'm looking for an
2009 Jul 02
2
constrained optimisation in R.
i want to estimate parameters with maximum likelihood method with contraints (contant numbers).
for example
sum(Ai)=0 and sum(Bi)=0
i have done it without the constraints but i realised that i have to use the contraints.
Without constraints(just a part-not complete):
skellamreg_LL=function(parameters,z,design)
{
n=length(z);
mu=parameters[1];
H=parameters[2];
Apar=parameters[3:10];
2011 Sep 02
5
Hessian Matrix Issue
Dear All,
I am running a simulation to obtain coverage probability of Wald type
confidence intervals for my parameter d in a function of two parameters
(mu,d).
I am optimizing it using "optim" method "L-BFGS-B" to obtain MLE. As, I
want to invert the Hessian matrix to get Standard errors of the two
parameter estimates. However, my Hessian matrix at times becomes
2004 Apr 27
1
constrOptim does ineq, not eq, but who do ?
Hi everybody,
please, could you give me help ? I scanned the help archives and didn't
found hints...
I want to solve a large sparse linear system subjected to an inequality
constrains (all solutions positive) and an equality constrain (all
solutions sum to 1), thus I tried to fool constrOptim using:
x[1] + 0 + ... + 0 >= 0
...
0 + 0 + ... + x[n] >= 0
x[1] + x[2] + ... +
2007 May 18
0
Cross-validation for logistic regression with lasso2
...y = binomial(), bound =
21)
Coefficients:
(Intercept) a b c d
e
-4.749816 2.776215 4.342661 8.956583 8.661593 1.264660
Family:
Family: binomial
Link function: logit
The absolute L1 bound was : 21
The Lagrangian for the bound is : 1.843283
Thanks
--
View this message in context: http://www.nabble.com/Cross-validation-for-logistic-regression-with-lasso2-tf3777173.html#a10680591
Sent from the R help mailing list archive at Nabble.com.
2009 Jul 23
0
How to get w in SVR with e1071 package
...;
> Hi all,
>
> I need some help about how to calculate w in a SVR in package e1071.
>
> I have a regression y_i=f(x_i)+e
>
> where f(*x*)=(w,phi(x))+b
>
> then go on with the SVR calculation I know that w*=Sum_i=1^n [(á_i -
> á*_i)K(x,x_i) ] where á_i and á*_i are the lagrangian multipliers of the
> dual form.
>
> o.k but how I will get it in R?
>
> When I run my model I have information about the model but I don't know how
> to use it to get w. Where are the alphas? Is w a vector or a value?
>
> Someone can help me please.
>
> Regards,
&g...
2014 Apr 25
0
Postdoctoral position at NIST
...levels of accuracy.
The successful applicant will conduct research using Bayesian and/or non Bayesian statistical methods to estimate emission fluxes and their associated un-certainties. The candidate will also work closely with other researchers in the field of mesoscale atmospheric models (WRF), Lagrangian particle models, tracer-transport and emission inventories to develop novel methodologies for estimating the flux of CO2 and CH4 to the atmosphere. The candidate will have the opportunity to collaborate within an inter-disciplinary team of scientists / engineers at various universities and research...
2007 May 10
2
Nonlinear constrains with optim
Dear All
I am dealing at the moment with optimization problems with nonlinear
constraints. Regenoud is quite apt to solve that kind of problems, but
the precision of the optimal values for the parameters is sometimes
far from what I need. Optim seems to be more precise, but it can only
accept box-constrained optimization problems. I read in the list
archives that optim can also be used with
2010 Aug 10
1
[Fwd: Re: optimization subject to constraints]
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2003 Jun 16
3
Constrained optimization
Greetings, R-Wizards:
I'm trying to find an extremum subject to a nonlinear constraint. (Yes, I
have perused the archives but have found nothing positive.) The details of
the problem are these:
In a paper published some years ago in Technometrics, ("Confidence bands for
cumulative distribution functions of continuous random variables"
Technometrics, 25, 77-86. 1983), Cheng and
2010 Jul 18
6
CRAN (and crantastic) updates this week
CRAN (and crantastic) updates this week
New packages
------------
* allan (1.0)
Alan Lee
http://crantastic.org/packages/allan
Automates Large Linear Analysis Model Fitting
* andrews (1.0)
Jaroslav Myslivec
http://crantastic.org/packages/andrews
Andrews curves for visualization of multidimensional data
* anesrake (0.3)
Josh Pasek
http://crantastic.org/packages/anesrake
This
2010 Dec 02
0
[PATCH] ssh.1: Clarify remote bind_address usage
Hi all,
A server with [GatewayPorts "yes"] also ignores client's remote
bind_address parameter, contrary to what is implied by the current
description.
Cheers!
Index: src/usr.bin/ssh/ssh.1
===================================================================
RCS file: /cvs/src/usr.bin/ssh/ssh.1,v
retrieving revision 1.316
diff -u src/usr.bin/ssh/ssh.1
--- src/usr.bin/ssh/ssh.1 18