Displaying 20 results from an estimated 40000 matches similar to: "Exponential smoothing"
2010 Jun 28
1
Exponential Smoothing: Forecast package
Hey,
I am using the ets() function in the forecast package to find out the best
fit parameters for my time-series. I have about 50 sets of time series data.
I'm currently using the function as follows:
ets(x,model="AZZ",opt.crit="mse")
As to my observation about 5-10 of them have been identified by ets to have
a trend and an alpha, beta values have been thrown up -
2001 Mar 27
1
Exponential smoothing
Dear all,
is there any function to do exponential smoothing of data in R?
I have searched all documentation (at least I hope I did) and found
nothing.
I know exp. smoothing is a somewhat old method and better ones exist,
but I want it for the reason of comparing results.
Greetings
Christoph
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list
2002 Jun 14
2
exponential smoothing
could someone help me to write a fonction doing an exponential smoothing in
case of a multivariate time serie?
I tried
ewma <- function (x, lambda = 1, init = 0)
{
if (is.ts(x))
filter(lambda*x, filter=1-lambda, method="recursive", init=init)
else
stop(message="first argument should be a time serie")
}
but I can't apply that to multivariate
Thanks
2009 Mar 31
2
Does R support double-exponential smoothing?
I want to use double-exponential smoothing to forecast time series
datas,but I couldn't find it in the document,does R support this
method?
2002 Apr 19
2
exponential smoothing
Dear R People:
Is there a function for exponential smoothing, please?
R version 1.4.1 for Windows.
Thanks in advance! Have a great weekend!
Sincerely,
Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
1 Main Street
Houston, TX 77002
mailto: hodgess at uhddx01.dt.uh.edu
2008 Aug 19
1
Exponential smoothing?
An r hel search picks up
http://tolstoy.newcastle.edu.au/R/help/01a/1162.html
from 2001, which points towards the ts package.
>>> ?hagen Patrik <Patrik.Ohagen at mpa.se> 19/08/2008 09:00:12 >>>
Dear List,
I have used all my resources (i.e. "help.search) and I still havn't been able to figure out if there is an Exponential Smoothing command in R.
Thank you in
2012 Nov 28
1
How to change smoothing constant selection procedure for Winters Exponential Smoothing models?
Hello all,
I am looking for some help in understanding how to change the way R
optimizes the smoothing constant selection process for the HoltWinters
function.
I'm a SAS veteran but very new to R and still learning my way around.
Here is some sample data and the current HoltWinters code I'm using:
rawdata <- c(294, 316, 427, 487, 441, 395, 473, 423, 389, 422, 458, 411,
433, 454,
2007 Nov 16
1
Exponential Smoothing for ggplot2's stat_smooth()
Hello everyone,
I was wondering if anyone was aware of a way in which I could use ggplot's
stat_smooth() function for add an exponential moving average.
I was thinking that I could maybe use something like:
>myggplot + stat_smooth (method = 'HoltWinters( data , .9 , 0, 0)')
but my efforts were futile.
Perhaps there is a way to write my own custom method to throw into
2008 Jul 18
0
Polynomial Approximation with Exponential Kernel
I'm trying to find an R package that will smooth a line with the "polynomial
approximation with exponential kernel" or "PAEK" algorithm that is used in
ESRI's ArcGIS software. I have a copy of the original paper that provides
the algorithm, but I'm not confident in how to code it. The algorithm will
smooth a polyline's vertices at a user specified distance
2011 Nov 29
3
Negative exponential fit
We need help....
We are doing a project for a statistical class in and we are looking at
world record times in different running events over time. We are trying to
fit the data with a negative exponential but we just cant seem to get a
function that works properly.
we have on our x-axis the date and on the y-axis the time(in seconds). So as
you can imagine, the times have decreased and appear to
2003 Mar 21
1
Savitzky-Golay Derivative and Smoothing
If I'm not mistaken, that's sort of local polynomial with even degree and
fixed bandwidth (based on my own interpretation of description in Numerical
Recipes). You can do that with functions in the KernSmooth package.
HTH,
Andy
> -----Original Message-----
> From: wolf at micro-biolytics.com [mailto:wolf at micro-biolytics.com]
> Sent: Friday, March 21, 2003 1:43 PM
> To:
2007 Mar 11
1
fitting a mixed exponential distribution
Hi all,
I am attempting to fit, and test the goodness of fit of, a mixed
exponential distribution to my dataset which consists of 15minute
rainfall intensity data. FYI, the dataset spanning approx.2 years and
7 rainfall stations consists of some three hundred thousand 15min data
records, of which some 30 thousand are non-zero rainfall amounts.
Could anyone please tell me how i could do
2010 Jan 11
0
Exponential regression
There are a couple of points to keep in mind when doing a log-transform of an exponential model, such as --
y = a*exp(b*x)
1. The implicit statistical model is multiplicative in the error. The implied
statistical model of the log transform is --
log(y) = log(a) + b*x + u
which implies --
y = a*exp(b*x)*exp(u)
A linear regression in the log
2003 Mar 27
2
Na action with Lowess smoothing
Hi there,
I cant seem to find a way for the lowess smoothing function to handle "NA"
values.
Can anyone help??
Regards,
Wayne
Dr Wayne R. Jones
Statistician / Research Analyst
KSS Group plc
St James''s Buildings
79 Oxford Street
Manchester M1 6SS
Tel: +44(0)161 609 4084
Mob: +44(0)7810 523 713
KSS Ltd
A division of Knowledge Support Systems Group plc
Seventh Floor St
2010 Jan 08
2
R exponential regression
Hi all,
I have a dataset which consists of 2 columns. I'd like to plot them on a x-y
scatter plot and fit an exponential trendline. I'd like R to determine the
equation for the trendline and display it on the graph.
Since I am new to R (and statistics), any advice on how to achieve this will
be greatly appreciated.
Many thanks,
Chris
--
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2008 May 16
1
HoltWinters fitted level parameter not bounded between 0 and 1 (PR#11469)
Full_Name: John Bodley
Version: 2.5.1 (2007-06-27)
OS: Windows XP
Submission from: (NULL) (12.144.182.66)
I was fitting a number of time series in R using the stats::HoltWinters method
to define a single exponential smoothing model, i.e., beta = gamma = 0.
I came across an example where the fitted value of alpha was not defined in the
[0, 1] interval which seems to violate the lower and upper
2009 Aug 19
1
New package for multivariate Kalman filtering, smoothing, simulation and forecasting
Dear all,
I am pleased to announce the CRAN release of a new package called 'KFAS' -
Kalman filter and smoother.
The package KFAS contains functions of multivariate Kalman filter,
smoother, simulation smoother and forecasting. It uses univariate approach
algorithm (aka sequential processing), which is faster than normal method,
and it also allows mean square prediction error matrix Ft to
2009 Aug 19
1
New package for multivariate Kalman filtering, smoothing, simulation and forecasting
Dear all,
I am pleased to announce the CRAN release of a new package called 'KFAS' -
Kalman filter and smoother.
The package KFAS contains functions of multivariate Kalman filter,
smoother, simulation smoother and forecasting. It uses univariate approach
algorithm (aka sequential processing), which is faster than normal method,
and it also allows mean square prediction error matrix Ft to
2008 Oct 22
0
ad.test exponential distribution
Hi,
I'm trying to use ad.test or ad2.test to test whether a given data set is
exponential. I see that one of the function inputs is "distn", but I try
"exponential" and 5 other variants, but I still get the error message:
ad.test(test2, distn="exponential", fit=list(estimate = 0.167685), H=NA,
sim=100)
Error in ad.test(test2, distn = "exponential",
2008 Oct 24
0
Weighted LSCV 2d kernel smoothing
R List,
I am seeking help in the area of kernel smoothing. I am attempting to use LSCV values to conduct 2d and weighted 2d kernel smoothing (imported from an ArcMap shapefile), and have been unable to find tools to conduct such analysis in R. My biggest problem is determining the LSCV value and finding a tool that does weighted smoothing, as there are obviously many different packages that will