Displaying 20 results from an estimated 3000 matches similar to: "Error in eigen(a$hessian) : infinite or missing values in 'x'"
2011 Nov 12
1
State space model
Hi,
I'm trying to estimate the parameters of a state space model of the
following form
measurement eq:
z_t = a + b*y_t + eps_t
transition eq
y_t+h = (I -exp(-hL))theta + exp(-hL)y_t+ eta_{t+h}.
The problem is that the distribution of the innovations of the transition
equation depend on the previous value of the state variable.
To be exact: y_t|y_{t-1} ~N(mu, Q_t) where Q is a diagonal
2011 Sep 22
1
Error in as.vector(data) optim() / fkf()
Dear R users,
When running the program below I receive the following error message:
fit <- optim(parm, objective, yt = tyield, hessian = TRUE)
Error in as.vector(data) :
no method for coercing this S4 class to a vector
I can't figure out what the problem is exactly. I imagine that it has
something to do with "tyield" being a matrix. Any help on explaining what's
going on
2011 Dec 29
0
problem of "constrOptim.nl", no hessian and convergence
Hi,
Use the `auglag' function in "alabama" if you want to get the Hessian at convergence. This typically tends to perform better than `constrOptim.nl'. Also, `constrOptim.nl' does not compute the Hessian. You should not specify method="L-BFGS-B". The default method "BFGS" is better in this setting.
Hope this helps,
Ravi
2010 Sep 21
2
Trouble with Optimization in "Alabama" Package
Hello,
This is my first post to the help request list, so I'm going to err on the
side of giving too much information.
I'm working on writing a simulation in which agents will make repeated
production and exchange decisions with randomly chosen partners.
The idea is, all agents can produce two goods which they want to consume,
they choose a value t in [0,10] which sets their production
2011 Nov 18
1
Ensuring a matrix to be positive definite, case involving three matrices
Hi,
I would like to know what should I garantee about P and GGt in order to have
F = Z %*% P %*% t(Z) + GGt always as a positive definite matrix.
Being more precise:
I am trying to find minimum likelihood parameters by using the function
'optim' to find the lowest value generated by $LogLik from the function
'fkf' (http://127.0.0.1:27262/library/FKF/html/fkf.html).
The
2011 Sep 02
5
Hessian Matrix Issue
Dear All,
I am running a simulation to obtain coverage probability of Wald type
confidence intervals for my parameter d in a function of two parameters
(mu,d).
I am optimizing it using "optim" method "L-BFGS-B" to obtain MLE. As, I
want to invert the Hessian matrix to get Standard errors of the two
parameter estimates. However, my Hessian matrix at times becomes
2011 May 18
1
Constrainted Nonlinear Optimization - lack of convergence
Hello,
I am attempting to utilize the 'alabama' package to solve a constrained
nonlinear optimization problem.
The problem has both equality and inequality constraints (heq and hin
functions are used). All constraints are smooth, i.e. I can differentiate
easily to produce heq.jac and hin.jac functions.
My initial solution is feasible; I am attempting to maximize a function,
phi. As
2023 Mar 20
0
Optimizing with constraints using alabama
Hi,
I am testing code that is working successfully using constrOptim. I am replacing constrOptim with other solvers to compare benefits and performance.
My belief was that, like constrOptim, auglag in the alabama package would eliminate beta vectors that failed the constraints prior to calling the objective
function. These betas are not only not in the solution space but also cause
2011 Dec 17
0
time-varying parameters kalman filter estimation problem using FKF package
Dear R users,
I am trying to carry out MLE of the time-varying CAPM using the FKF package.
My approach so far has been to try and adapt the example given in the help
file found using ?fkf which demonstrates the MLE of an ARMA(2,1) model.
When I attempt to run my R code (given below) I get the following error:
Error in fkf(a0 = sp$a0, P0 = sp$P0, dt = sp$dt, ct = sp$ct, Tt = sp$Tt, :
Some of
2018 May 02
0
Merging dataframes
Hi,
I'll coded your example into R code:
Table_A <- c('abc at gmail.com', 'John Chan', '0909')
Table_A <- rbind(Table_A, c('bcd at yahoo.com', 'Tim Ma', '89089'))
colnames(Table_A) <- c('Email', 'Name', 'Phone')
Table_A
Table_B <- c('abc at gmail.com', 'John Chan', 'M',
2012 Apr 30
2
The constant part of the log-likelihood in StructTS
Dear all,
I'd like to discuss about a possible bug in function StructTS of stats
package. It seems that the function returns wrong value of the
log-likelihood, as the added constant to the relevant part of the
log-likelihood is misspecified. Here is an simple example:
> data(Nile)
> fit <- StructTS(Nile, type = "level")
> fit$loglik
[1] -367.5194
When computing the
2013 Feb 10
3
Constrained Optimization in R (alabama)
Dear List,
I'm trying to solve this simple optimization problem in R. The parameters
are the exponents to the matrix mm. The constraints specify that each row
of the parameter matrix should sum to 1 and their product to 0. I don't
understand why the constraints are not satisfied at the solution. I must be
misinterpreting how to specify the constrains somehow.
library(alabama)
ff <-
2013 Feb 11
0
Error in R (ENFA) : Error in eigen(Se) : infinite or missing values in 'x'
Dear all,
I am running an Ecological Niche Factor Analysis in R but I am stuck with a
problem. As soon as I ask the software to compute the ENFA, I get the
following error message:
Error in eigen(Se) : infinite or missing values in 'x'
Does anyone know what could be wrong. I do not have missing values in my
dataset.
Please follow the codes I used for my analysis so far:
library
2009 Nov 29
2
Time Series Rating Model
To R programming experts,
I am a undergraduate student, and now doing research personally. I apply diagonal bivariate poisson (R package "bivpois") with stochatics weighted function (refer to dixoncoles97 section 4.5 to 4.7). However I dont know how to fit this stochatical weighted function to the completed bivariate poisson model.
I know that some other references for dynamic soccer
2011 Dec 29
0
problem of "constrOptim.nl", no hessian and convergence values
Dear Helper,
I used "constrOptim.nl" and got the value of par. The estimations looks good
even if the number of iterations is only 16. But the values of hessian and
convergence are both "NULL".
I tested the objective function and gradient function by "optim" and didn't
see any problem there. With these functions, "optim" gives the convergence
value
2010 Oct 05
1
nonlinear curve fit of an implicit function
Hello,
I want to perform a nonlinear curve fit in order to obtain parameter
estimates from experimentally determined data (y in dependence of x),
but with an implicit function, thus, a function of which I cannot
isolate y on the left-hand side of the equation. As far as I understand,
the functions I found up to now (nls, optim) all work only for explicit
functions.
My data looks like
2018 May 02
2
Merging dataframes
Thanks - Peter, Eivind, Rui
Sorry, I perhaps could not explain it properly in the first go.
Trying to simplify it here with an example - Say I have two dataframes as
below that are NOT equally-sized data frames (i.e., number of columns are
different in each table):
Table_A:
Email Name Phone
abc at gmail.com John Chan 0909
bcd at yahoo.com Tim Ma
2010 Nov 18
0
Any help understand the FKF package? Thanks.
Dear Fellow R Users,
I am experimenting right now the FKF package. I started by working out the first example included in the package and I am already confused. Would you offer some kind suggestions? What I want to do is to write down the state transition equation and the measurement equation explicitly.
Following the first example:
According to: dt <- matrix(0, nrow = 2)
the state vector
2003 Jun 10
1
Minor quibble with eigen and La.eigen (PR#3221)
Hi everyone,
It's a very minor point, but could we ensure that eigen and La.eigen
return a *matrix* for the "vectors" component of the list by including a
"drop = FALSE", as specified in the help file, ie put
list(values = z$values[ord], vectors = if (!only.values) z$vectors[,
ord, drop = FALSE])
Thanks, Jonathan.
--please do not edit the information
2006 Aug 10
3
Geometrical Interpretation of Eigen value and Eigen vector
Dear all,
It is not a R related problem rather than statistical/mathematical. However
I am posting this query hoping that anyone can help me on this matter. My
problem is to get the Geometrical Interpretation of Eigen value and Eigen
vector of any square matrix. Can anyone give me a light on it?
Thanks and regards,
Arun
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