Displaying 20 results from an estimated 4000 matches similar to: "acf()"
1999 Aug 31
1
Vector-isation
Hi,
Suppose I have a by b matrix which a and b are big numbers. How can I
convert this matrix into a vector with length of a*b ? By column-wise or
row-wise doesnt matter. My R version is 0.64.2.
Kindest Regards,
Peppy Adi-Purnomo
-------
Stephanus (Peppy) Adi-Purnomo
Energy Market Analyst - Energy Link Ltd - Dunedin
email: s.adi.purnomo at energylink.co.nz
http://www.energylink.co.nz
2000 Jun 21
3
SAS dataset
Hello,
Is there any way we convert SAS dataset into R dataset?
Kindest Regards,
Peppy Adi-Purnomo
------
Peppy Adi-Purnomo
Energy Market Analyst
Energy Link Ltd
Dunedin - New Zealand
Ph.: +64 3 479 2475
Fax: +64 3 477 8424
Email: s.adi.purnomo at energylink.co.nz
www.EnergyLink.co.nz
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r-help mailing list -- Read
1999 Aug 18
1
R 0.64.2 indexing
Hi,
> Say we have a large-sized vector of observation A and a time vector with
> the same size. The latter vector basically is the time flag when ith
> obervation of A occurs, hence A[i] occurs at T[i].
>
> I have no trouble with doing: T[A <= 10 | A >=20] for example
>
> Now, what I am confused: I tried to pull out when the largest value of A
> with:
>
>
1999 Oct 14
1
Regression on non linear model
Dear Help desk,
I have a model that I believe to be non linear. The relationship is
something like:
Response = Var1 + Var1^2 + Var1^3
Can I examine this relationship using glm or lm? However, glm or lm gives
out pnly 1 coeficient for the model which is on Var1, unless I created some
dummy var like (Var2 = Var1^2 and Var3 = Var1^3).
Is there any other function handling this relationship?
1999 Oct 14
1
Regression on non linear model
Dear Help desk,
I have a model that I believe to be non linear. The relationship is
something like:
Response = Var1 + Var1^2 + Var1^3
Can I examine this relationship using glm or lm? However, glm or lm gives
out pnly 1 coeficient for the model which is on Var1, unless I created some
dummy var like (Var2 = Var1^2 and Var3 = Var1^3).
Is there any other function handling this relationship?
2000 Sep 22
6
lme
Hello,
I need to use a procedure in R that similar to lme in Splus.. is this
particular procedure has been implemented in the recent version? thanks.
Regards,
Peppy Adi-Purnomo
Energy Market Analyst
Energy Link Ltd
Telp.: +64 3 479 2475
Fax. : +64 3 477 8463
www.energylink.co.nz
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r-help mailing list -- Read
2000 Aug 10
1
anova
hello,
I have a very old R version which calculates anova table for a stream of
outcomes say: 1,5,4,3,2,4,5,2 which are grouped into 4 blocks, say A,B,C,D,
of 2 say namely X,Y
What is the command in R 0.64.2 to do this? My very old R command is
anova.table but this command is unkown in R 0.64.2
Thanks,
Peppy
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r-help
2010 Nov 07
1
When using ACF, receive error: no applicable method for 'ACF' applied to an object of class "c('double', 'numeric')"
I am guessing this is a very simple question, but this is only my second day
with R so it is all still a bit imposing.
I am trying to run an autocorrelation.
I imported a CSV file, which has one column labeled "logistic".
I ran the command:
ACF(data$logistic,maxLag=10)
However, I received the error:
Error in UseMethod("ACF") :
no applicable method for 'ACF'
2010 Apr 29
1
a question on autocorrelation acf
Hi R users,
where can I find the equations used by acf function to calculate
autocorrelation? I think I misunderstand acf. Doesn't acf use following
equation to calculate autocorrelation?
[image: R(\tau) = \frac{\operatorname{E}[(X_t - \mu)(X_{t+\tau} -
\mu)]}{\sigma^2}\, ,]
If it does, then the autocorrelation of a sine function should give a
cosine; however, the following code gives a
2010 Apr 17
2
interpreting acf plot
Hello,
I am attending a course in Computational Statistics at ETH and in one of the assignments I am asked to prove that a time series is not autocorrelated using the R function "acf".
I tried out the acf function with the given data, according to what I found here: http://landshape.org/enm/options-for-acf-in-r/ this test data does not look IID but rather shows some trends so how can I
1999 Aug 10
1
Problems with the ts library
Well, I upgraded to a later release and have been having good luck (R vers.
0.65.0) I haven't upgraded my Red-Hat linux from 5.2 so I had to compile from
source , ... so far so good. My problem is with the time series functions
[library(ts)]. I'm trying to use the autocorrelation function-acf() and am
having problems with it. mainly an error ERROR -Couldn't find function
2011 Aug 25
1
Autocorrelation using acf
Dear R list
As suggested by Prof Brian Ripley, I have tried to read acf literature. The main problem is I am not the statistician and hence have some problem in understanding the concepts immediately. I came across one literature (http://www.stat.nus.edu.sg/~staxyc/REG32.pdf) on auto-correlation giving the methodology. As per that literature, the auto-correlation is arrived at as per following.
2009 Aug 05
2
acf Significance
Hi List,
I'm trying to calculate the autocorrelation coefficients for a time
series using acf at various lags. This is working well, and I can get
the coefficients without any trouble. However, I don't seem to be able
to obtain the significance of these coefficients from the returned acf
object, largely because I don't know where I might find them.
It's clear that the acf
2005 Oct 10
1
acf.plot() question
When I run the "acf()" function using the "acf(ts.union(mdeaths,
fdeaths))" example, the "acf()" function calls the "acf.plot()"
function to generate this plot...
http://members.cox.net/ddebarr/images/acf_example.png
The plot in the lower right-hand corner is labeled "fdeaths & mdeaths",
but the negative lags appear to belong to "mdeaths
2008 Aug 06
1
using acf() for multiple columns
Hi everyone,
I'm trying to use the acf() function to calculate the autocorrelation of
each column in a matrix. The trouble is that I can only seem to get the
function to work if I extract the data in the column into a separate matrix
and then apply the acf() function to this column.
I have something like this: acf(mat,lag.max=10,na.action=na.pass)
...but I would really like to apply the
2008 Nov 20
1
different ACF results
Dear all,
I have one Model (M3) fitted using the lme package, and I have
checked the correlation structure of within-group errors using
plot(ACF (M3,maxLag=10),alpha=0.05)
But now I am not sure how to interpret this plot for the empirical
autocorrelation function.
The problem is that I am used to see/interpret diagrams in which all
the autocorrelation Lags, except lag-1, are inside the
2008 Jan 17
1
acf lag1 value
Hi R,
I have doubt.
>x= c(4,5,6,3,2,4,5)
>acf(x,plot=F,lag.max=1)
Autocorrelations of series 'x', by lag
0 1
1.000 0.182
But if I actually calculate the autocorrelation at lag1 I get,
>cor(x[-1],x[-length(x)])
[1] 0.1921538
Even in excel I get 0.1921538 value. So, I want to know what the 'acf'
function is calculating here....
2004 Mar 09
2
corARMA and ACF in nlme
Hi R-sters,
Just wondering what I might be doing wrong. I'm trying to fit a multiple
linear regression model, and being ever mindful about the possibilities of
autocorrelation in the errors (it's a time series), the errors appear to
follow an AR1 process (ar(ts(glsfit$residuals)) selected order 1). So,
when I go back and try to do the simultaneous regression and error fit with
gls,
2010 Sep 26
1
acf function
Hi,
Im new to R so this question is quite fundamental.
Im trying to compare some autocorrelations generated by the acf function to some theoretical correlations. How can I have acces to just the autocorrelations, for computation?
This is some of my code:
> acf.data<-c(acf(x))
> acf.data
This is the R output:
$acf
, , 1
[,1]
[1,] 1.000000000
[2,]
2006 Aug 18
3
Query: how to modify the plot of acf
I need to modify the graph of the autocorrelation. I tried to do it through plot.acf but with no success.
1. I would like to get rid of the lag zero
2. I would like to have numbers on the x-axis only at lags 12, 24, 36, 48, 60, ...
Could anybody help me in this?
Any help will be appreciated
Thank you for your attention
Stefano
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