Displaying 20 results from an estimated 800 matches similar to: "auto.arima forecasting issue"
2009 Jan 23
1
forecasting error?
Hello everybody!
I have an ARIMA model for a time series. This model was obtained through an
auto.arima function. The resulting model is a ARIMA(2,1,4)(2,0,1)[12] with
drift (my time series has monthly data). Then I perform a 12-step ahead
forecast to the cited model... so far so good... but when I look the plot of
my forecast I see that the result is really far from the behavior of my time
2007 Mar 02
0
R: ARIMA forecasting
Dear all,
I just have a short question regarding the forecasting of ARIMA models with
external regressors.
I tried to program a ARX(1) model
arx.mod <- arima(reihe.lern, order = c(1, 0, 0), seasonal =
list(order = c(0, 0, 0), period = 52), xreg = lern.design, include.mean =
TRUE)
for which I need to estimate the next (105th) value. Xreg=lern.design is -
at this time - 104 rows long. I
2009 Jan 21
1
forecasting issue
Hello everybody!
I have a problem when I try to perform a forecast of an ARIMA model
produced by an auto.arima function. Here is what I'm doing:
c<-auto.arima(fil[[1]],start.p=0,start.q=0,start.P=0,start.Q=0,stepwise=TRUE,stationary=FALSE,trace=TRUE)
# fil[[1]] is time series of monthly data
ARIMA(0,0,0)(0,1,0)[12] with drift : 1725.272
ARIMA(0,0,0)(0,1,0)[12] with drift
2013 Mar 22
0
predict.Arima error "'xreg' and 'newxreg' have different numbers of columns"
Hello all,
I use arima to fit the model with
fit <- arima(y, order = c(1,0,1), xreg = list.indep, include.mean = TRUE)
and would like to use predict() to forecast:
chn.forecast <- rep(0,times=num.record)
chn.forecast[1] <- y[1]
for (j in 2:num.record){
indep <- c(aa=chn.forecast[j-1], list.indep[j,2:num.indep]) # this is the newxreg in the
2009 Feb 17
0
What's the predict procedure of ARIMA in R?
Hello,guys:
Recently, I am working on a seasonal ARIMA model. And I met some problem in the forecasting.
Now I just want to know that How does R perform the predict procedure(the predict formula, the initial setting of errors,etc.)?
I run the following commands and get the original code of the "predict" command, but I can't read it.
Can anybody explain it to me?
Thanks!
saji from
2010 Mar 31
1
predict.Arima: warnings from xreg magic
When I run predict.Arima in my code, I get warnings like:
Warning message:
In cbind(intercept = rep(1, n), xreg) :
number of rows of result is not a multiple of vector length (arg 1)
I think this is because I'm not running predict.Arima in the same
environment that I did the fit, so the data object used in the fit is no
longer present. Looking at the predict.Arima source,
2009 Nov 24
4
Method
Hello, i would like to ask you another question. Is exist anymethod to
vectors that tells me the last element?That is to say,I have a vector, I
want to return the position of last element. I hope having explained.
A greeting,
Ignacio.
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2008 Jul 08
0
forecast & xreg
Dear all,
I am fitting an arimax (arima with some extra explanatory variables)
model to a time series. Say, I have a Y (dependent variable) and an X
(explanatory).
Y is 100 observations (time series) and X is 100 + 20 (20 to use for the
forecast horizon).
I can not make xreg work with the forecast function for an arima fit.
The "predict" function seems to be working but the
2009 Jan 26
2
how to modify an R built-in function?
Hello R experts!
Last week I run in to a lot a problems triyng to fit an ARIMA model to a
time series. The problem is that the internal process of the arima function
call function "optim" to estimate the model parameters, so far so good...
but my data presents a problem with the default method "BFGS" of the optim
function, the output error looks like this:
Error en
2005 Jul 08
1
help with ARIMA and predict
I'm trying to do the following out of sample
regression with autoregressive terms and additional x
variables:
y(t+1)=const+B(L)*y(t)+C(1)*x_1(t)...+C(K)*x_K(t)
where:
B(L) = lag polynom. for AR terms
C(1..K) = are the coeffs. on K exogenous variables
that have only 1 lag
Question 1:
-----------
Suppose I use arima to fit the model:
2012 Apr 26
1
Using the R predict function to forecast a model fit with auto.arima function
Hello R users,
Hope everyone is doing great.
I have a dataset that is in .csv format and consists of two columns: one
named Period (which contains dates in the format yyyy_mm) and goes from
1995_10 to 2007_09 and the second column named pcumsdry which is a
volumetric measure and has been formatted as numeric without any commas or
decimals.
I imported the dataset as pauldataset and made use of
2003 Apr 16
0
arima function - estimated coefficients and forecasts
I'm using the arima function to estimate coefficients and also using
predict.Arima to forecast. This works nicely and I can see that the
results are the same as using SAS's proc arima.
I can also take the coefficent estimates for a simple model like
ARIMA(2,1,0) and manually compute the forecast. The results agree to 5
or 6 decimal places. I can do this for models with and without
2003 Dec 18
0
Help with predict.Arima with external regressor values
Hi all there
I am enjoying R since 2 weeks and I come to my first deadlock, il am trying
to use predict.Arima in the ts package.
I get a "Error in cbind(...) : cannot create a matrix from these types"
-- Start R session -----------------------------------------------------
> fitdiv <- arima(data, c(2, 0, 3), xreg = y ) ; print(fitdiv)
Call:
arima(x = data, order = c(2, 0, 3),
2009 Dec 19
3
DROP and KEEP statements in R
What is equivalent to DROP or KEEP statements of SAS in R?
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2008 Jan 27
2
maptools no such file
Hello,
I'm having problems reading a shapefile with read.shape (maptools). I'm absolutely sure my file is there, but I get "no such file". The wd is ok, since read.table for example does find the file.
> getwd()
[1] "D:/somedirectory/R scripts"
> read.table("cities.shp")
Error in read.table("cities.shp") : empty beginning of file
In addition:
2007 Nov 20
2
barplot problem
Hello,
I'm trying to find out how I can move the y axis label of a horizontal barplot further away from the axis, in order to avoid overlap between the names (which I have rotated using las=1) and the label. I have been fiddling with the graphical parameters but nothing seems to work. Maybe a graphical representation of the graphical parameters would be helpful (cf the CSS box model).
2003 Dec 18
1
Help with predict.Arima with external regressor values [Repalced]
Hi all there
I am enjoying R since 2 weeks and I come to my first deadlock, il am trying
to use predict.Arima in the ts package.
I get a "Error in cbind(...) : cannot create a matrix from these types"
-- Start R session -----------------------------------------------------
> fitdiv <- arima(data, c(2, 0, 3), xreg = y ) ; print(fitdiv)
Call:
arima(x = data, order = c(2, 0, 3),
2006 Mar 09
2
How to assign channels for asterisk
helleo ,I have one wildcard installed on the server,and configured it.there are
two modules which both FXOs .all configurations complete,and when we start asterisk use "asterisk -vvvvc",it shows asterisk ready,no warnings.afterwards when the sever connected to the PSTN in the one port which configured,and have a phone line connected to the other port then run
2006 Apr 18
1
Nonlinear Regression model: Diagnostics
Hi,
I am trying to run the following nonlinear regression model.
> nreg <- nls(y ~ exp(-b*x), data = mydf, start = list(b = 0), alg = "default", trace = TRUE)
OUTPUT:
24619327 : 0
24593178 : 0.0001166910
24555219 : 0.0005019005
24521810 : 0.001341571
24500774 : 0.002705402
24490713 : 0.004401078
24486658 : 0.00607728
24485115 : 0.007484372
2011 Jan 28
2
[LLVMdev] The type or size of virtual registers
Thanks for your help with me about the way to access type and size of Value.
But, I want also know the interface for me to access the type or size of
virtual registers in the SSA form.
1. I find no way to associate the virtual registers with the Value class.
2. I also tried to get the size of register nReg by:
TargetRegisterClass::getSize(), where the TargetRegisterClass object is
obtained by