Displaying 20 results from an estimated 1000 matches similar to: "Estimation in a changepoint regression with R"
2002 Sep 11
2
changepoint analysis
Hi, all,
I'd like to find one or more changepoints in a dataset
eg
for data like
0.9 1 0.8 0.8 0.85 0.3 0.9 0.9 0.9 1.1
0.3 is unlikely a changepoint
but for data like
0.9 1 0.8 0.8 0.85 0.3 0.2 0.2 0.1 0.2 0.3
0.3 is a change point
I am wondering is there any function can do changepoint analysis?
Ying Fan
2023 Feb 15
1
p-value in changepoint package
Hello Does anyone know how to get the p values for changepoints in the
"changepoint" package? There is guidance in the CRAN vignette
https://cran.r-project.org/web/packages/changepoint/changepoint.pdf but I
can't make it work to get the p value out... Thanks Nick Wray
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2010 Nov 16
3
Population abundance, change point
I am trying to understand my population abundance data and am looking into
analyses of change point to try and determine, at approximately what point
do populations begin to change (either decline or increasing).
Can anyone offer suggestions on ways to go about this?
I have looked into bcp and strucchange packages but am not completely
convinced that these are appropriate for my data.
Here is
2014 Sep 16
1
Changepoint analysis--is it possible to attribute changpoints to explanatory variables?
Hello,
I would like to evaluate the relationship between flows and phytoplankton abundance (or Chlorophyll a concentrations) using a changepoint analysis.? Specifically, I have two study questions:
Study Question 1: Are there certain flow thresholds that result in spikes in phytoplankton abundance?
Study Question 2: Are the duration of certain flows important for phytoplankton abundance (e.g.,
2009 Sep 05
8
Color index in image function
Dear All,
I was looking for the color index in?image function,?such as from topo.colors(n) and etc. but still never found it. For instance, from the help menu.
###########################################
# Volcano data visualized as matrix. Need to transpose and flip
# matrix horizontally.
image(t(volcano)[ncol(volcano):1,])
# A prettier display of the volcano
x <- 10*(1:nrow(volcano))
y
2009 Sep 23
4
Problem in graph plotting
Dear All,
Let:
dp: depth of the?river
tp: temperature with respect to depth
We can?have a simple scatter plot, between depth as y-axis and temperature as x-axis,?by using a?plot function as shown?below.
#####################?
dp <- c(1,4,3,2,5,7,9,8,9,2)
tp <- 1:10
plot(tp,dp, type= 'l')
#####################
?
Could someone advice me on?the way to?plot the same pair of
2010 Jan 22
4
How to seperate date and time into different columns?
Dear All,
I have a series of data in which the first column consist of a combination of date and time, for instance 17 April 2008 at 4.01pm, such data is recorded as:
4/17/2008 16:01
I'd like to seperate it into four different columns which consist of Day, Month,Year and Time, respectively.
Could someone please advice me on this mater?
Thank you,
Fir
2009 Sep 22
3
How to combine matrices?
Dear All,
Let a, b and c are?three matrices with same no. of column but different no. of row.
a <- matrix(1, 1, 2)
b <- matrix(2, 2, 2)
c <- matrix(3, 3, 2)
Could someone help me to combine these matrices together as a single matrix?
Thank you
Fir
2023 Apr 01
1
weird things in seqMK() and sqmk()
Hello The other say I posted a question about altering confidence limits
in the seqMK() function in the pheno package. I didn't get any bites but
in any case I've been trying to use this function. It seems to me to give
very odd results - sometimes identifying 8 or 9 changepoints in a
relatively short vector of maybe 40 elements, and at other times not giving
any changepoints at all,
2011 May 04
3
best subset regression in R
Dear All,
Could someone please give some advice the way to do linear modelling via best subset regression in R? I'd really appreciate for your kindness.
Thanks,
Kagba
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2005 Sep 09
2
best way to fit a model
Hi,
I have some data that have this behaviour:
|
|*******
| *
| *
| *
| *
|----------------
What is the best and simpler way to fit this in R?
Thanks
Ronaldo
--
Ela pilotava um Continenal 2001 com igni????o autom??tica Magiclic...
--
|> // | \\ [***********************************]
| ( ?? ?? ) [Ronaldo Reis J??nior ]
|>
2010 Apr 02
4
Derivative of a smooth function
Dear All,
I've been?searching for?appropriate codes to compute the rate of change and the curvature?of ?nonparametric regression model whish was denoted by a smooth function?but?unfortunately?don't manage to?do?it. I presume that such characteristics from a smooth curve can be determined by the first and second derivative operators.
The following are the example of fitting a
2010 Aug 13
2
Kalman filter
Dear All,
Could anyone?give me a hand?to suggest few packages in R to running Kalman
prediction and filtration ?
Thanks
Fir
2011 May 04
2
Box-Cox transformation in R
Hi,
Could any one please help how I can transform data based on Box-Cox Transformations in R.
Any helps will be much appreciated.
thanks,
Kagba
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2009 Oct 02
2
How to speed up R with version 2.9.2?
Dear All,
I'm sorry if my question does not suit with this R group.
I have recently installed?R software with version 2.9.2, but i found the program took almost 1 minute as soon as it was opened, before it can be used. However,?the previous version 2.9.1 only take few seconds?after the menu bar was clicked. This circumstance has caused me to wait for couple of minutes as several R windows
2009 Sep 24
3
Color of the plot which correspond to the group of the observations
Dear All,
?
Let:
dp: depth of the river
tp: temperature with respect to depth
These pair of observations are in 3 different groups i.e:
Obs. 1,3,5,7?from the first group
Obs. 2,4 and?10?from second group
Obs 6,8 and 9?from third group.
We can have a simple scatter plot, between depth as y-axis and temperature as x-axis, with each pairs are denoted by a red dot, by using a plot function shown
1999 Aug 17
1
linking object files
Dear friends. I would like to link an object file made in C. Dyn.load rather wants to link a whole library and I only wanted to link this small object file. I followed instructions given for S - by Clive Loader in his software for changepoint handling and it is his object file I made from http://cm.bell-labs.com/cm/ms/departments/sia/clive/smcp.shar
Any dirty tricks or easy oversights ?
Yours
2010 Feb 09
1
question about nlme...
I am looking for R code to be able to fit a linear-linear piecewise
model with person-specific changepoint. I have searched the web, but
have not been able to locate any code.
Below is my attempt at some code:
chgpt = function(a1,a2,a3,gam,wave){
yht=numeric(10)
y1=(wave <= gam)*(a1+(a2*wave))
y2=(wave > gam)*((a1+(a2-a3)*gam)+a3*wave)
yhat=y1+y2
return(yht)
}
nl.dat <- nlme(y ~
2005 Apr 14
2
grubbs.test
Dear All,
I have small samples of data (between 6 and 15) for
numerious time series points. I am assuming the data
for each time point is normally distributed. The
problem is that the data arrvies sporadically and I
would like to detect the number of outliers after I
have six data points for any time period. Essentially,
I would like to detect the number of outliers when I
have 6 data points then
2012 Jun 27
1
Strucchange: Breakpoint slow
Hi to all,
I am trying to run breakpoints() on a fairly large sample (>10.000
observations). The process is very slow, any idea on how to speed this up? I
have tried the hpc="foreach" parameter, but this didn't work at all when I
tried to run it on a smaller sample.
breakpoints(x ~ x.l1 + x.l2 + X.l3 + x.l4 + x.l5 + x.l6 + x.l7 + x.l8 + y.l1
+ y.l2 + y.l3 + y.l4 + y.l5 + y.l6