Displaying 20 results from an estimated 10000 matches similar to: "question on adding confidence intervals"
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 <-
2005 Aug 11
3
question on creating a new logical variable
I have two variables.
A <- rep(c(1:9), 2)
B <- rep(c(2:10),2)
--
Renuka Sane
http://www.nyx.net/~rsane
[[alternative HTML version deleted]]
2005 Aug 02
5
question on graphs and finding area under a curve
Question on graphs:
The default case for drawing a graph in R, is where a little space is left
on the x and y axis before the first tick i.e. even if I say xlim=c(0,1) --
there will be some space between the edge of the x-axis and where 0 is
placed. If I want 0 on the edge, how do I do it in R?
Area under the curve:
I have a 45 degree line and a curve above or below it. Is there a way in R
2017 Dec 26
1
Time Series with Neural Networks
Hi,
I am would like to ask few questions.
I am trying to forecast hourly electricity prices by 24 hours ahead.
I have hourly data starting from 2015*12*18 to 2017-10-24
and I have defined the data as time series as written in the code below.
Then I am trying do neural network with 23 non-seasonal dummies and 1 seasonal dummy.
But I don?t know whether training set is enough.( Guess it is 50
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
2007 Dec 01
1
modeling time series with ARIMA
Good afternoon!
I'm trying to model a time series on the following data, which represent a monthly consumption of juices:
>x<-scan()
1: 2859 3613 3930 5193 4523 3226 4280 3436 3235 3379 3517 6022
13: 4465 4604 5441 6575 6092 6607 6390 6150 6488 5912 6228 10196
25: 7612 7270 8617 9535 8449 8520 9148 8077 7824 7991 7660 12130
37: 9135 9512 9631 12642
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
2013 Feb 05
1
R -HELP REQUEST
Good morning to you all,
Sorry for taking your time from your research and
teaching schedules.
If you have a non-stationary univariate time Series
data that has the transformation:
Say; l.dat<-log (series)
d.ldat<-diff (l.dat, differences=1)
and you fit say arima model.
predit.arima<-predict (fit.series, n.ahead=10,
xregnew= (n+1) :( n+10))
How could I re-transform
2011 Jun 16
1
prediction intervals
Dear members,
I'm fitting linear model using "lm" which has numerous auto-regressive terms as well as other explanatory variables. In order to calculate prediction intervals, i've used a for-loop as the auto-regressive parameters need to be updated each time so that a new forecast and corresponding prediction interval can be calculated.
I'm fitting a number of these models
2010 Feb 08
0
confidence interval for negatively skewed, leptokurtic sample
Hello,
I?ve got a statistical problem that I hope you can help me with. It doesn?t
have to do directly with R, so if there?s another forum which would suit
better, please tell me!
Now here?s the problem:
I want to derive confidence intervals for a variable X, which is - given the
descriptive statistics - obviously negatively skewed and leptokurtic (i.e.
peaked). My aim is to make a statement
2020 Oct 18
1
Help in R code
Good morning,??Please help me to code this code in R.
I working in the multivariate time series data, know my objective is that to one year forecast of the hourly time series data, using first five as a training set and the remaining one year as validation. For this??I transform the the data into functional data through Fourier basis functional, apply functional principle components as dimensional
2006 Nov 25
2
predict and arima
Hi all,
Forecasting from an arima model is easy with predict.
But I can't manage to backcast : invent data from the model before the
begining of the sample.
The theory is easy : take your parameters, reverse your data, forecast, and
then reverse the forecast
I've tried to adapt the predict function to do that (i'm not sure that the
statistical procedure is fine (with the residuals),
2010 Oct 07
1
Forecasting with R/Need Help. Steps shown below with the imaginary data
1. This is an imaginary data on monthly outcomes of 2 years and I want to forecast the outcome for next 12 months of next year.
data Data1;
input Yr Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec;
datalines;
2008 12 13 12 14 13 12 11 15 10 12 12 12
2009 12 13 12 14 13 12 11 15 10 12 12 12
;
run;
I converted the above data into the below format to use it in R as it was giving error: asking
2020 Oct 14
1
Help in Coding
Good morning dear administrators,
Please help me to code this code in R.
I working in the multivariate time series data, know my objective is that to one year forecast of the hourly time series data, using first five as a training set and the remaining one year as validation. For this??I transform the the data into functional data through Fourier basis functional, apply functional principle
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
2010 Sep 06
1
Prediction and confidence intervals from predict.drc
R-helpers,
I am using the package "drc" to fit a 4 parameter logistic model. When I
use the predict function to get prediction on a new dataset, I am not
getting the requested confidence or prediction intervals. Any idea what
is going on? Here is code to reproduce the problem:
---
library(drc)
# Fit model to existing dataset in package
spinach.model <- drm(SLOPE~DOSE, data =
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
2010 Jan 11
1
HoltWinters Forecasting
Hi R-users,
I have a question relating to the HoltWinters() function. I am trying to
forecast a series using the Holt Winters methodology but I am getting some
unusual results. I had previously been using R for Windows version 2.7.2 and
have just started using R 2.9.1. While using version 2.7.2 I was getting
reasonable results however upon changing versions I found I started to see
unusual
2007 Dec 11
1
question regarding arima function and predicted values
Good evening!
I have a question regarding forecast package and time series analysis.
My syntax:
x<-c(253, 252, 275, 275, 272, 254, 272, 252, 249, 300, 244, 258, 255, 285, 301, 278, 279, 304, 275, 276, 313, 292, 302, 322, 281, 298, 305, 295, 286, 327, 286, 270, 289, 293, 287, 267, 267, 288, 304, 273, 264, 254, 263, 265, 278)
library(forecast)
arima(x, order=c(1,1,2),
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