Displaying 20 results from an estimated 3000 matches similar to: "Arima forecasting"
2009 Jul 21
1
Forecasting - Croston Method Error
Hi,
I tried to use the Croston function from the forecasting package
1.24<http://robjhyndman.com/software/forecasting> with
the code below, but I get in return this message "*Error in
decompose(ts(x[1L:wind], start = start(x), frequency = f), seasonal) : time
series has no or less than 2 periods*".
histValues
2010 Dec 30
2
key-value mapping in C inside R?
I'm testing some modifications in arima.c.
I've noticed that a big internal array of double (rbar) is usually
sparse and I'd like to add an option to store it as key-value mapping.
Is there a library function or some other approach already used inside
the R core for key-value mappings?
Thanks,
Matteo Bertini
2011 Jun 15
1
Query regarding auto arima
I am using AUTO ARIMA for forecasting. But it is not detecting 'seasonality
term' of its own for any data.
Is there any other method by which we can detect seasonality and its
frequency for any data?
Is there any method through which seasonality and its frequency can be
automatically detected from ACF plot?
--
Siddharth Arun,
4th Year Undergraduate student
Industrial Engineering and
2009 Sep 09
1
Forecast - How to create variables with summary() results parameters
Hi,
I would like to create variables in R containing parameters of
summary(*Forecast
Results*).
Using the following code:
library(forecast)
data <- AirPassengers
xets <- ets(data, model="ZZZ", damped=NULL)
xfor <- forecast(xets,h=12, level=c(80,95))
summary(xfor)
the output is:
Forecast method: ETS(M,A,M)
Model Information:
ETS(M,A,M)
Call:
ets(y = data, model =
2011 Dec 13
2
Problem with ploting fitted values
Hello!
I have such a problem...
Estimated a model based on common data (you can find it in R library), and I
wanted to plot the orginal values with the estimated one. Unfortunately I
can only see the original values.
Below is the code with data library:
/
library(forecast)
data(AirPassengers)
AP <- AirPassengers
class(AP)
start(AP)
end(AP)
frequency(AP)
lgAP <- log(AP)
t<-2:length(AP)
2023 Jan 05
1
R 'arima' discrepancies
Rob J Hyndman gives great explanation here
(https://robjhyndman.com/hyndsight/estimation/) for reasons why results
from R's arima may differ from other softwares.
@iacobus, to cite one, 'Major discrepancies between R and Stata for
ARIMA'
(https://stackoverflow.com/questions/22443395/major-discrepancies-between-r-and-stata-for-arima),
assign the, sometimes, big diferences from R
2008 Oct 15
1
Forecasting using ARIMAX
Dear R-helpers,
I would appreicate if someone can help me on the transfer parameter in ARIMAX and also see what I am doing is correct.
I am using ARIMAX with 2 Exogeneous Variables and 10 years data are as follows:
DepVar Period, depVar, IndepVar1 Period, indepVar1, IndepVar2 Period, indepVar2
Jan 1998,708,Jan 1998,495,Jan 1998,245.490
Feb 1998,670,Feb 1998,421.25,Feb 1998,288.170
Mar
2007 Nov 16
1
monthplot () - axis change color
Hi,
When I run this code a part of my x-axis and y-axis changes color. Can
somebody tell me what is wrong? Also, is there a way to control the color of
the average lines?
monthplot(AirPassengers+500, ylim=c(min(AirPassengers),
max(AirPassengers+500)), ylab="")
par(new=T)
monthplot(AirPassengers, col="blue", ylim=c(min(AirPassengers),
max(AirPassengers+500)),
2010 Nov 22
2
Help: Standard errors arima
Hello,
I'm an R newbie. I've tried to search, but my search skills don't seem
up to finding what I need. (Maybe I don't know the correct terms?)
I need the standard errors and not the confidence intervals from an
ARIMA fit.
I can get fits:
> coef(test)
ar1 ma1
intercept time(TempVector) - 1900
2012 Jan 21
2
How to identify data structure?
data(AirPassengers) brings AirPassengers into the workspace. How can I idenfity what the structure of AirPassengers is? Is it a data.frame, a table etc. etc.
[[alternative HTML version deleted]]
2011 Jul 28
3
construct a data set
Hi,
i want to construct a data set similar to "AirPassengers".
Its attributes are following.
> attributes(AirPassengers)
$tsp
[1] 1949.000 1960.917 12.000
$class
[1] "ts"
How Can I construct a data set similar to it having same class and attributes.
Thanks
--
Amar Kumar Nandan
?:nandan.amar at gmail.com
http://aknandan.co.nr
2004 Jul 18
2
stl,package=stats
Greetings:
I'm using the time series decomposition routine "stl" from the package "stats".
But how do I get the results into a vector to work with them?
example:
data(AirPassengers)
m<-stl(AirPassengers,"per")
print(m)
This lists the output but can't figure out how to extract the individual series like seasonal, trend, irregular.
Thanks,
Bob
2012 Jan 29
2
Data Structure to Code
Given:
data(AirPassengers)
I get a ts data structure AirPassengers in the workspace.
How can I generate the code that can create that structure? That is, given an example of a data structure, is there a way to generate the code that can greate that structure?
Alternatively, is there a reference that provides a list of dta structures together with a full list of theor respective attributes?
2011 Jun 02
1
Line histogram for a matrix
Hi guys!
I'm new to R, but I was wondering if one could plot many histograms into a
single graph each having a different color. To make things clear:
Suppose you have a matrix of 100 rows and 10 columns. I'm interested in
plotting the histogram for each row, but it should not appear as bars but
rather as lines connecting the points of the frequencies. Now, I want to do
this for the 100
2015 Jun 12
2
Serie temporal interrumpida del tipo AirPassengers
Hola usuarios,
Necesito detectar si existe o no un cambio de tendencia y si dicho cambio es significativo, para una serie temporal del tipo AirPassengers, en la que
a partir de un determinado momento se ha hecho una campaña (supongamos que una promoción de vuelos).
Para ello he pensado varios métodos:
Usar la descomposición espectral de la muestra [decompose(AirPassengers)] y luego una Regresión
2007 Dec 04
1
Best forecasting methods with Time Series ?
Hello,
In order to do a future forecast based on my past Time Series data sets
(salespricesproduct1, salespricesproduct2, etc..), I used arima() functions
with different parameter combinations which give the smallest AIC. I also
used auto.arima() which finds the parameters with the smallest AICs. But
unfortuanetly I could not get satisfactory forecast() results, even
sometimes catastrophic
2009 Jan 18
1
auto.arima forecasting issue
Hello everybody!
I'm having this problem with the auto.arima function that i've not been
able to solve. I use this function on time series that contains NA values,
but every time that the resulting model contains drift I can't perform a
forecasting (using forecast.Arima function). The printed error (when I try
to forecast the resulting model) claims a dimension mismatch
2010 Mar 23
2
wxGrid merge cell
It''s possible merge two or more cell ???
ex:
--------------------------------------
| LABEL 1 | LABEL 2 | LABEL 3 |
--------------------------------------
| VALUE CELL MERGE | ANOTHER |
--------------------------------------
| | | |
--------------------------------------
Many Thanks
Carlo Bertini
www.waydotnet.com
--
Posted via
2011 Nov 30
2
forecasting linear regression from lagged variable
I'm currently working with some time series data with the xts package, and
would like to generate a forecast 12 periods into the future. There are
limited observations, so I am unable to use an ARIMA model for the forecast.
Here's the regression setup, after converting everything from zoo objects to
vectors.
hire.total.lag1 <- lag(hire.total, lag=-1, na.pad=TRUE)
lm.model <-
2011 Mar 08
3
This is supposed to predict a time series?!
Hello,
I just ran the predict.StructTS function using the AirPassengers data
and got a ridiculous result. Here's what I ended up with:
http://24.210.155.111/PredictWhat!.pdf
Who wrote this? Am I seriously supposed to think this function would
accurately predict a time series?
-AnalogKid