Displaying 11 results from an estimated 11 matches for "g_t".
Did you mean:
_t
2012 Oct 23
1
scatterplot with wrong line offset
Hi All,
I'm trying to do a Scatterplot (package: car), and add a line (just for
reference).
There is my code:
#------------------------------------Code---------------------------------------------------
library("car")
library("calibrate")
G_T<-c("car","bike","boat")
ave<-c(80,10,45)
perf<-c(100,80,75)
df2<-data.frame(G_T,ave,perf)
scatterplot(ave ~ perf, data=df2,smoother=FALSE,xlim=c(0,100),ylim=c(0,100))
textxy(df2$perf,df2$ave...
2010 Oct 06
1
dlm package: how to specify state space model?
...ion over time. The general form of a state space model
is
(1) b_t = G * b_t-1 + w_t w_t ~ N(0,W)
(2) y_t= A' * x_t + H' * b_t + v_t v_t ~ N(0,V)
(Hamilton 1984: 372)
The investment function I would like to use for estimating my endogenous
capacity utilization rate looks like
(3) g_t = x[1] + x[2]*(u_t-un_t) + x[3]*r + v_t
where g_t is the investment rate, r_t is the profit rate, u_t is the
actual utilization rate and un_t is the 'normal' utilization rate which
I take as endogenous (=time varying). x[i] are parameters. I'm
particularly interested in this endogenous...
2005 Dec 14
1
Kalman Filter Forecast using 'SSPIR'
Dear R Users,
I am new to state-space modeling. I am using SSPIR
package for Kalman Filter. I have a data set containing one dependent
variable and 7 independent variables with 250 data points. I want to use
Kalman Filter for forecast the future values of the dependent variable
using a multiple regression framework. I have used ssm function to
produce the state space (SS)
2006 Dec 20
2
Kalman Filter in Control situation.
I am looking for a Kalman filter that can handle a control input. I thought
that l.SS was suitable however, I can't get it to work, and wonder if I am
not using the right function. What I want is a Kalman filter that accepts
exogenous inputs where the input is found using the algebraic Ricatti
equation solution to a penalty function. If K is the gain matrix then the
exogenous input
2008 May 07
1
dlm with constant terms
Hi,
I am trying to figure how to use dlm with constant terms
(possibly time-dependent) added to both equations
y_t = c_t + F_t\theta_t + v_t
\theta_t = d_t + G_t\theta_{t-1} + w_t,
in the way that S-PLUS Finmetrics does?
Is there any straightforward way to transform the above to
the default setup?
Thanks,
Tsvetan
--------------------------------------------------------
NOTICE: If received in error, please destroy and notify sender. Sender does not intend...
2010 Sep 28
0
Time invariant coefficients in a time varying coefficients model using dlm package
...ers,
I am trying to estimate a state space model of the form
(1) b_t = G * b_t-1 + w_t w_t ~ N(0,W)
(2) y_t= A' * x_t + H' * b_t + v_t v_t ~ N(0,V)
(Hamilton 1984: 372)
In particular my estimation in state space form looks like
(3) a3_t = 1 * a3_t-1 + w_t w_t ~ N(0,W)
(4) g_t = (a1, a2) * (1, P_t)' + u_t * a3_t + v_t v_t ~ N(0,V)
where g_t is the investment rate, P_t are profits and u_t is the
utilization rate. As you can see, I would like to estimate the
coefficient of the utilization rate in time-varying terms and all the
other coefficients of the investment f...
2003 Dec 02
2
model of fish over exploitation
...ock of each period t
* the production function
Ht(St, Xt) = alpha*St*Xt
Ht the catch for each period t
Xt fishing effort for each period t
alpha parameter of boat productivity
* the dynamic of the fish stock
S(t+1) = S(t) + Gt - Ht
I would like to modelise the following system:
S_(t+1) = S_t + G_t - H_t
G_t = r*S_t*(1-S_t / sbar)
H_t = alpha * S_t * X_t
S_1961 = S_0
I know only H_t on period (1961 - 1994) and X_t on the same period.
I don't know r, sbar, alpha and S_0 (the initial level of the stock)
(and of course S_t on this period) and I want to estimate this four
parameters.
I have...
2009 Feb 15
0
Kalman Filter - dlm package
Dear all,
I am currently trying to use the "dlm" package for Kalman filtering.
My model is very simple:
Y_t = F'_t Theta_t + v_t
Theta_t = G_t Theta_t-1 + w_t
v_t ~ N(0,V_t) = N(0,V)
w_t ~ N(0,W_t) = N(0,W)
Y_ t is a univariate time series (1x1)
F_t is a vector of factor returns (Kx1)
Theta_t is the state vector (Kx1)
G_t is the identity matrix
My first challenge is to get the Maximum Likelihood estimators of V and W
assum...
2007 Nov 24
0
Help on State-space modeling
...e functions on R, I got to the function ss on the
library sspir. From what I
understood this function is similar to SsfFit from S-PLUS. But for my models
purpose there is something
left to be desired. Its formulation follow these equations:
*Y_t = F_t^T * theta_t + v_t, v_t ~ N(0,V_t)*
*theta_t = G_t * theta_{t-1} + w_t, w_t ~ N(0,W_t)*
Actually I wanted to add these two functions (-logA and a)
Y(t) = -log(A(t))/tau + (B(t)/tau) * X(t) + Error (measurement equation)
X(t) = a(t) + b(t) * X(t-1) + Error (Transition
Equation)
Have anyone tried something like that?
Bes...
2008 Oct 30
0
a nlm() question
Dear R listers,
I have a very annoying problem using nlm().
I want to find the minimizer of my target function, if written in
\LaTeX is
f(\mu1,\mu2,\sigma1,\sigma2) = \sum_i^n( w_ig_t(z_i) ), where
g_t(z) is a pdf of bivariate normal distribution and z_i is my samples.
I cannot get the estimation result generated by nlm(), and I got
the following errors
"
Error in nlm(foo, theta.start, hessian = TRUE) :
non-finite value supplied by 'nlm'
"
f...
2006 Apr 29
1
SSPIR problem
I am having a problem with the package SSPIR. The code below
illustrates it. I keep getting the message: "Error in y - f :
non-conformable arrays."
I tried to tweak the code below in many different ways, for example,
substituting rbind for cbind, and sometimes I get a different error
message, but I could not find a variation of this code that would
work.
Any help will be greatly