Displaying 20 results from an estimated 1000 matches similar to: "Arima Models - Error and jump error"
2011 Jun 21
1
Doubit about ts() functions
Hi everyone
Please, I need one more help you
I have some data that need to make a forecast.
I´m using the command: Yst<-print(ts<-ts(Y,start=c(1,5),freq=7),calendar=T)
to create the dayly time series by the dataframe Y.
My data Y means: Y=measure dayly , start at 01/jul/2010 (thursday), for this
reason that I use c(1,5).
I need to create the time series aggregate by weakly (and not dayly as
2011 Jun 21
2
function to undo the DIFF command in ARIMA command
Hi users.
I'm new user in R.
I'm workiing with Time series and I would like to know how can I do to undo
the command DIFF(X), for exemple:
If I have the model: m=arima(X, order=c(0,1,1),
seasonal=list(order=c(0,0,1))) (note that have d=1 one difference), to find,
in the same scale, the original numbers (like one "unDiff"), after the
forecast, I need to develop some function or in
2009 Oct 09
1
Substituting the extracted coefficients into the formula, exctracted from the result of nls()
Dear all,
Here I come with another stupid question. Suppose I want to use nls()
to fit a series of data (here modelled by generated points), then plot
the points and the fitting curve. I figured out some way of doing it:
x <- runif(1:20, 0, 10)
y <- 0.1*x^2 - rep(3, length(x)) + rnorm(length(x), sd = 0.5)
yfit <- nls(y ~ a*x^2 + b*x + c,
start = list(a = 1, b = 1, c = 1),
2010 Nov 10
1
par mfrow in "function" problem
Hi all,
I defined the following
#############################
myhist=function(x){
hist(x,xlab="",main="")
h=hist(x)
xfit=seq(min(x),max(x),length=100)
yfit=dnorm(xfit,mean(x),sd=sd(x))
yfit=yfit*diff(h$mids[1:2])*length(x)
lines(xfit, yfit, col="blue", lwd=2)
}
#############################
individually, it worked fine
however, if I used
par(mfrow=c(2,2))
2009 Jun 21
2
Help on qpcR package
I am using R on a Windows XP professional platform.
The following code is part of a bigger one
CODE
press=function(y,x){
library(qpcR)
models.press=numeric(0)
cat("\n")
dep=y
print(dep)
indep=log(x)
print(indep)
yfit=dep-PRESS(lm(dep~indep))[[2]]
cat("\n yfit\n")
print(yfit)
yfit.orig=yfit
presid=y-yfit.orig
press=sum(presid^2)
2009 Sep 02
2
Howto fit normal curve into histogram using GGPLOT2
Currently, I am doing it this way.
x <- mtcars$mpg
h<-hist(x, breaks=10, col="red", xlab="Miles Per Gallon",
main="Histogram with Normal Curve")
xfit<-seq(min(x),max(x),length=40)
yfit<-dnorm(xfit,mean=mean(x),sd=sd(x))
yfit <- yfit*diff(h$mids[1:2])*length(x)
lines(xfit, yfit, col="blue", lwd=2)
But since, ggplot2 has more appealing
2005 Oct 14
1
lattice with predicted values
Dear lattice wizards,
I am trying to figure out how to plot predicted values in xyplot,
where the intercept, but not the slope, varies among conditioning
factor levels. I am sure it involves the groups, but I have been
unsuccessful in my search in Pinhiero and Bate, in the help files, or
in the archive, or in my attempts on my own.
My example follows:
FACT is a factor with levels a,b,c
2010 Feb 19
1
"Legend" question
Hi,
I want to get a histogram with the legend for my data. I drew a normal density curve and kernel density curve in the histogram, and I also label mean and median in the X axis. From the code, I got two legend: One shows "Normal Density" and "Kernel Density" and their corresponding lines, the other shows "Mean = value" and "Median = value" and their
2007 Jun 07
2
Nonlinear Regression
Hello
I followed the example in page 59, chapter 11 of the 'Introduction to R'
manual. I entered my own x,y data. I used the least squares. My function has
5 parameters: p[1], p[2], p[3], p[4], p[5]. I plotted the x-y data. Then I
used lines(spline(xfit,yfit)) to overlay best curves on the data while
changing the parameters. My question is how do I calculate the residual sum
of squares.
2013 Aug 07
3
Documentation error: wrong permissions given in FAQ
Hi,
I discovered yesterday that the instructions given at http://www.openssh.org/faq.html#3.14 regarding the correct permissions for the authorized_keys file mistakenly recommend chmod'ing the file to 600 when it should be 644. The requirement for public key authentication to work is in fact that ~/.ssh/authorized_keys is readable (but not writable) by group and other, not just owner. Someone
2004 Sep 27
1
optim error in arima
Hello,
I'm fitting a series of ARIMA models to a data set to compare fits. After taking the logs of the data and then differencing them to induce stationarity, I execute
arima( y, order=c( p, 0, q ), seasonal=list( order=c( P, 0, Q ), period=7 ) )
for various values of p, q, P and Q. For one set of these values, I get
Error in optim(init[mask], armafn, method = "BFGS", hessian
2011 Aug 30
2
ARMA show different result between eview and R
When I do ARMA(2,2) using one lag of LCPIH data
This is eview result
>
> *Dependent Variable: DLCPIH
> **Method: Least Squares
> **Date: 08/12/11 Time: 12:44
> **Sample (adjusted): 1970Q2 2010Q2
> **Included observations: 161 after adjustments
> **Convergence achieved after 14 iterations
> **MA Backcast: 1969Q4 1970Q1
> **
> **Variable Coefficient Std.
2006 Jul 03
0
Questions concerning function 'svm' in e1071 package
Greetings everyone,
I have the following problem (illustrating R-code at bottom of mail):
Given a training sample with binary outcomes (-1/+1), I train a linear
Support Vector Machine to separate them. Afterwards, I compute the
weight vector w in the usual way, and obtain the fitted values as
w'x + b > 0 ==> yfitted = 1, otherwise -1.
However, upon verifying with the
2001 Oct 13
2
hist and normal curve
Dear R people:
I would like to superimpose a normal curve on a histogram.
I've seen this example in a book, somewhere.
I know that you draw the hist, get the mean and sd
of the data set, but then I'm stuck.
Could you help, please?
Thanks!
Erin
hodgess at uhddx01.dt.uh.edu
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2012 Aug 24
0
A question about GRAMMAR calculations in the FAM_MDR algorithm
Dear R developers:
I am a PHD candidate student in the school of public health of Peking
University and my major is genetic epidemiology. I am learning the FAM-MDR
algorithm, which is used to detect the gene-gene and gene-environment
interactions in the data of pedigree. The codes were written by Tom
Cattaert of the University of Liege. The algorithms and the sample datasets
are available at
2005 Sep 25
4
hist(x, ...) with normal distribution curve
.
I am looking for a histogram or box plot with the adding normal
distribution curve
I think that must be possible, but I am not able to find out how to do.
Regards Knut
2008 Jan 11
1
question about xreg of arima
Hi,
I am trying to understand exactly what xreg does in arima. The documentation
for xreg says:"xreg Optionally, a vector or matrix of external regressors,
which must have the same number of rows as x." What does this mean with
regard to the action of xreg in arima?
Apparently somehow xreg made the following two arima fit equivalent in R:
arima(x, order=c(1,1,1), xreg=1:length(x))
is
2008 Jul 29
1
optim fails when using arima
Hi all,
I?m using the arima() function to study a time series but it gives me
the following error:
Error en optim(init[mask], armafn, method = "BFGS", hessian = TRUE,
control = optim.control, :
non-finite finite-difference value [3]
I know that I can change the method of the arima() to "CSS" instead of
"ML" but I'm specially interested in using
2007 Jan 16
2
ARIMA xreg and factors
I am using arima to develop a time series regression model, I am using arima
b/c I have autocorrelated errors. Several of my independent variables are
categorical and I have coded them as factors . When I run ARIMA I don't
get any warning or error message, but I do not seem to get estimates for all
the levels of the factor. Can/how does ARIMA handle factors in xreg?
here is some example
2012 Mar 20
1
MA process in panels
Dear R users,
I have an unbalanced panel with an average of I=100 individuals and a total
of T=1370 time intervals, i.e. T>>I. So far, I have been using the plm
package.
I wish to estimate a FE model like:
res<-plm(x~c+v, data=pdata_frame, effect="twoways", model="within",
na.action=na.omit)
?where c varies over i and t, and v represents an exogenous impact on x