Displaying 20 results from an estimated 600 matches similar to: "predict a MA timeseries"
2008 Jul 25
3
Numerical question
Hi all,
I have n independent variables A_1, A_2, A_3,......,A_n, and each with known variances var(A_1), var(A_2),..., but unknown mean. How can I get the approximation of the variance of the product of the variables using numerical computation, i.e. var(A_1*A_2*A_3*.....*A_n)? Thanks.
Sincerely,
Yanwei Zhang
Department of Actuarial Research and Modeling
Munich Re America
Tel: 609-275-2176
2011 Nov 06
2
how to use quadrature to integrate some complicated functions
Hello to all,
I am having trouble with intregrating a complicated uni-dimensional function
of the following form
Phi(x-a_1)*Phi(x-a_2)*...*Phi(x-a_{n-1})*phi(x-a_n).
Here n is about 5000, Phi is the cumulative distribution function of
standard normal,
phi is the density function of standard normal, and x ranges over
(-infty,infty).
My idea is to to use quadrature to handle this integral. But
2007 Feb 21
1
loops in R help me please
I am trying to make the following Kalman filter equations work and therefore produce their graphs.
v_t=y_t - a_t
a_t+1=a_t+K_t*v_t
F_t=P_t+sigma.squared.epsilon
P_t+1=P_t*(1-K_t)+sigma.squared.eta
K_t=P_t/F_t
Given:
a_1=0,P_1=10^7,sigma.squared.epsilon=15099,
sigma.squared.eta=1469.1
I have attached my code,which of course doesnt work.It produces NAs for the Fs,Ks and the a.
Can somebody tell me
2012 Jan 30
2
how to select columns
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2018 May 09
0
more reassociation in IR
When you say that distribution shouldn't be used, do you mean within
instcombine rather than some other pass? Or not all as an IR optimization?
A dedicated optimization pass that looks for and makes
factoring/distribution folds to eliminate instructions seems like it would
solve the problems that I'm seeing.
Ie, I'm leaning towards the proposal here: https://reviews.llvm.org/D41574
2006 Jan 02
6
Paginate with joins messing with id
Hi all,
Best wishes for the new year! :'')
I''m very new to Ruby and Rails, and I ran into a problem with the
"paginate" function. When I use the following method to get a number
of forum topics based on a category name passed via the URI:
@topic_pages, @topics = paginate :topics,
:joins => "INNER JOIN categories ON
2008 Aug 24
0
[LLVMdev] Dependence Analysis [was: Flow-Sensitive AA]
> I asked myself the same question. Without mod, how do you ensure that for instance the expression 2*i+255 was not actually 2*i-1 ?
I think it is not possible in general, but I believe it is possible in
case of affine expressions used as GEP indices.
I assume, GEP indices (except indexing into struct) are interpreted as
signed integers. It isn't explicitly stated in the LangRef, but
2008 Aug 22
5
[LLVMdev] Dependence Analysis [was: Flow-Sensitive AA]
>However, there is one issue I have ignored - possibility of overflow in
>the index expression. Suppose, we have such a loop:
> for (i8 i = 0; i != 200; ++i) {
> A[2 * i + 5] = ...
> ... = A[2 * i + 3]
> }
>If both index expressions are evaluated in 8-bit arithmetic,
>then the dependence equation should be solved in modular arithmetic:
> 2 * i + 5 == 2 * (i +
2018 May 09
4
more reassociation in IR
> On May 8, 2018, at 9:50 AM, Daniel Berlin via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>
> 1. The reassociate pass that exists right now was *originally* (AFAIK) written to enable CSE/GVN to do better.
Agreed. The original mindset included a (naive) belief that going with a canonical form was better than teaching redundancy elimination to handle abstractions (as a matter
2015 Oct 15
3
potencia fracional de un número negativo
Mirando los comentarios, realmente lo que deseo es encontrar la raíz real
de (-0.5)^(1/5) la cual debería ser -0.87055056329. José me hace caer en
cuenta que además de no encontrar la raiz real, tampoco da todas las raiz
complejas. Habría alguna manera de que tuviera en cuenta?
> ------------------------------
>
> Message: 6
> Date: Thu, 15 Oct 2015 11:25:39 +0200
> From: José
2009 Jun 15
4
books on Time series
Dear list fellows,
I want to study time series and use R to analyse time series of fishing
data from several species (landings and cpue) investigating the
correlation between them and with environmental factors (water
temperature, wind, etc.).
Searching at Amazon I found three books with examples in R:
Time Series Analysis: With Applications in R by Jonathan D. Cryer and
Jonathan D. Cryer
2017 Jun 20
1
How to write an estimated seasonal ARIMA model from R output?
I'm trying to use the following command.
arima (x, order = c(p,d,q), seasonal =list(order=c(P,D,Q), period=s)
How can I write an estimated seasonal ARIMA model from the outputs. To be specifically, which sign to use? I know R uses a different signs from S plus.
Is it correct that the model is:
(1-ar1*B-ar2*B^2-...)(1-sar1*B^s-sar2*B^2s-....)(1-B)^d(1-B^s)^D
2005 Jan 21
2
transfer function estimation
Dear all,
I am trying to write an R function that can estimate Transfer functions *with additive noise* i.e.
Y_t = \delta^-1(B)\omega(B)X_{t-b} + N_t
where B is the backward shift operator, b is the delay and N_t is a noisy component that can be modelled as an ARMA process. The parameters to both the impulse response function and the ARMA noisy component need to be estimated simultaneously.
I
2009 Apr 26
1
simulate arima model
I am new in R.
I can simulate Arma, using Arima.sim
However, I want to simulate an Arima Model. Say (1-B)Zt=5+(1-B)at. I do not
know how to deal with 5 in this model.
Can any one could help me?
Thank you very much!
Regards,
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2011 Nov 20
1
alpha_1 + beta_1 >1 in GARCH(1,1)
Hi,
as i suppose to know in a stationary GARCH(1,1) model the sum of alpha and
beta has to be smaller than 1.
But if i use the garchfit() function from the package fGarch for my
timeseries the sum is bigger than 1.
The adf.test tells me a p-value smaller than 0.01 instead.
What does this mean for me?
Can i trust in the coefficients in this case?
mfg user84
--
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2013 Sep 26
1
Queue Management
Dear All,
I have six different campaign and 5 different agent have login on that
campaign.*Same thing i have done using agi and database,i never use queue
management on this scenario. Agent** can also shuffling one campaign to
anther campaign. *
Now i want to do some work with queue.I want to use single queue to
managing this.
Eg:
campaign Agent Login
A
a_1,a_3
2007 Mar 29
3
Tail area of sum of Chi-square variables
Dear R experts,
I was wondering if there are any R functions that give the tail area
of a sum of chisquare distributions of the type:
a_1 X_1 + a_2 X_2
where a_1 and a_2 are constants and X_1 and X_2 are independent chi-square variables with different degrees of freedom.
Thanks,
Klaus
--
"Feel free" - 5 GB Mailbox, 50 FreeSMS/Monat ...
2010 Aug 23
1
Fitting a GARCH model in R
Hi,
I want to fit a mean and variance model jointly.
For example I might want to fit an AR(2)-GARCH(1,1) model i.e.
r_t = constant_term1 + b*r_t-1 + c*r_t-2 + a_t
where a_t = sigma_t*epsilon_t
where sigma^2_t = constant_term2 + p*sigma^2_t-1 + q*a^2_t-1
i.e. R estimates a constant_term1, b, c, constant_term2, p, q
TIA
Aditya
2006 Mar 23
2
Default lag.max in ACF
Hi,
The default value for lag.max in ACF implementation is 10*log10(N)
There several publications recommending setting lag.max to:
- N/4 (Box and Jenkins, 1970; Chatfield, 1975; Anderson, 1976;
Pankratz, 1983; Davis, 1986; etc.)
- sqrt(N)+10 (Cryer, 1986)
- 20<=N<=40 (Brockwell and Davis)
Why R uses 10*log10(N) as a default?
Please, give me a reference to a book or article where the
2012 Feb 29
2
How to replace the values in a column
Dear All,
I've been searching relevant topics about replacing values, none seemed to
be applicable to me...
I have a file with many many varieties, and want to replace some of them
into different names.
I tried various of ways, still don't know how to do that most efficiently..
Here is part of the example data:
Gen Rep
A_1 1
A_1 2
A_2 1
A_2 2
B_1 1
B_1