Displaying 20 results from an estimated 766 matches for "forecast".
2013 Mar 15
2
Help finding first value in a BY group
I have a large Excel file with SKU numbers (stock keeping units) and
forecasts which can be mimicked with the following:
Period <- c(1, 2, 3, 1, 2, 3, 4, 1, 2)
SKU <- c("A1","A1","A1","X4","X4","X4","X4","K2","K2")
Forecast <- c(99, 103, 128, 63, 69, 72, 75, 207, 201)
PeriodSK...
2010 Dec 25
4
need help with data management
I have a data frame that reads
client ID date transcations
323232 11/1/2010 22
323232 11/2/2010 0
323232 11/3/2010 missing
121212 11/10/2010 32
121212 11/11/2010 15
.................................
I want to order the rows by client ID and date and using a black-box
forecasting method create the data fcst(client,date of forecast, date
for which forecast applies).
Assume that I have a function that given a time series
x(1),x(2),....x(k) will generate f(i,j) where f(i,j) = forecast j days
ahead, given data till date i.
How can the forecast data be best stored and how...
2009 Aug 07
3
How do I plot a line followed by two forecast points?
Good day all,
I'm trying to plot a continuous line plot, which is followed by two
forecast points eg. one forecast point is 12 months out, and another
24 months out from the last date of the line plot.
In my attempts so far, the second plot (the forecast points) is scaled
against a new axis scale, thus the two plots are not directly
comparable (I need the forecast points to be scaled ac...
2008 Aug 12
1
arima forecast function
hi:
I am trying to fit prediction intervals for an arima object. My search led
me to the link:
http://finzi.psych.upenn.edu/R/library/forecast/html/forecast.Arima.html
which has the function "forecast", as I wanted. However, when I try to run
it in R, I get the message:
Error in plot(forecast(fit)) : could not find function "forecast"
Even the example provided on the page (having corrected the function "Arima&q...
2006 Sep 02
0
New forecasting bundle of packages
v1.0 of the forecasting bundle of packages is now on CRAN and will
propagate to mirrors shortly.
The forecasting bundle of R packages provides new forecasting methods,
and graphical tools for displaying and analysing forecasts. It comprises
the following packages:
* forecast: Functions and methods for forecas...
2006 Sep 02
0
New forecasting bundle of packages
v1.0 of the forecasting bundle of packages is now on CRAN and will
propagate to mirrors shortly.
The forecasting bundle of R packages provides new forecasting methods,
and graphical tools for displaying and analysing forecasts. It comprises
the following packages:
* forecast: Functions and methods for forecas...
2008 Feb 28
2
EMM: how to make forecast using EMM methods?
Hi all,
We followed some books and sample codes and did some EMM estimation,
only to find it won't be able to generate forecast.
This is because in the stochastic volatility models we are estimating,
the volatilities are latent variables, and we want to forecast 1-step
ahead or h-step ahead volatilities.
So it is nice to have the system estimated, but we couldn't get it to
forecast at all.
There is a "Reprojecti...
2009 Dec 16
1
R and Hierarchical Forecasting
Hello, does anyone know of any R routines capable of whats called
Hierarchical Forecasting, reconciling the different hierarchies.
Example: A top down forecast where the corporate forecast is created and
then all the regions within the corporate entity are also forecasted,
with the constraint they sum to the corporate forecast.
2008 Sep 22
1
Prediction errors from forecast()?
Hello,
I am using forecast() in the forecast package to predict future values of an
ARIMA model fit to a time series. I have read most of the documentation for
the forecast package, but I can't figure out how to obtain the forecast
variance for the predicted values. I tried using the argument
"se.fit=TRUE," h...
2012 Feb 29
2
How to extract numerical values from time series forecast
hi all. i'm busy with some time series data, starting from an earlier period
until the current day.
i have created a time series forecast taking into account the entire data
from the earlier date up until 2007, using the "forecast" package for R. i
am comparing this forecasted data to the actual/ observed data (which starts
from the earlier date up until the current day).
my question is, how do i extract the estimated data...
1998 Nov 19
1
list assignment
There appears to be a problem with name matching in list assignment:
Version 0.63.0 (November 14, 1998)
...
> r <- list()
> r$forecast.cov.trend <- 1:12
> r$forecast.cov.zero <- 1:12
> r$forecast.cov <- 1:2
> length(r$forecast.cov)
[1] 0 #should be 2
>
But note that this works correctly:
> r <- list()
> r$forecast.cov.trend <- 1:12
> r$forecast.cov <- 1:2
&...
2012 Jan 18
1
forecasting a time series
Couldn't find this in the archives. I'm fitting a series of historical
weather-related data, but would like to use the latest values to forecast.
So let's say that I'm using 1970-2000 to fit a model (using fourier terms
and arima/auto.arima), but now would like to use the last X values to
predict tomorrow's weather. I'm at a loss. All the functions I've come
across (like forecast()) use the series and then forecast from...
2010 Mar 11
4
Forecast
sample report data that i want to forecast
quarter quarter_index Revenue
2007 Q1 1 $3,856,799
2007 Q2 2 $4,243,328
2007 Q3 3 $4,930,369
2007 Q4 4 $5,443,579
2008 Q1 5 $5,164,830
2008 Q2...
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, mo...
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 satisf...
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 <- lm(hire.total ~ cas...
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
series... in fact, there is a considerable gar between the last value of
the series and the first forecast. My guess is that I'm doing something
wron...
2010 Mar 19
1
Arima forecasting
Hello everyone,
I'm doing some benchmark comparing Arima [1] and SVR on time series data.
I'm using an out-of-sample one-step-ahead prediction from Arima using
the "fitted" method [2].
Do someone know how to have a two-steps-ahead forecast timeseries from Arima?
Thanks,
Matteo Bertini
[1] http://robjhyndman.com/software/forecast
[2] AirPassengers example on page 5
2007 Jan 24
1
n step ahead forecasts
hello,
I have a question about making n step ahead forecasts in cases where test
and validation sets are availiable. For instance, I would like to make one
step ahead forecasts on the WWWusage data so I hold out the last 10
observations as the validation set and fit an ARIMA model on the first 90
observations. I then use a for loop to sequentially add 9 o...
2011 Jul 04
1
forecast: bias in sampling from seasonal Arima model?
Dear all,
I stumbled upon what appears to be a troublesome issue when sampling from an
ARIMA model (from Rob Hyndman's excellent 'forecast' package) that contains
a seasonal AR component.
Here's how to reproduce the issue. (I'm using R 2.9.2 with forecast 2.19;
see sessionInfo() below).
First some data:
> x <- c(
0.132475, 0.143119, 0.108104, 0.247291, 0.029510, -0.119591, -0.133313,
-0.098128, 0.192698, 0...