Displaying 17 results from an estimated 17 matches for "extremas".
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extrema
2011 Feb 11
1
Help optimizing EMD::extrema()
Hi folks,
I'm attempting to use the EMD package to analyze some neuroimaging
data (timeseries with 64 channels sampled across 1 million time points
within each of 20 people). I found that processing a single channel of
data using EMD::emd() took about 8 hours. Exploration using Rprof()
suggested that most of the compute time was spent in EMD::extrema().
Looking at the code for EMD:extrema(),
2002 Jul 26
5
Is there a function for finding local extrema.
I have a vector with about 100.000 values representing a quite regular
function (sinusoid like).
I would like to find all local maxima of this function (should be about
4000). Is there a native routine for R?
Thanks in advance
Eryk.
--
_|_ \|/ \|/ Eryk Witold Wolski tel :0049-(0)30-8413-1543 w w
?v? 'v? \'v'/ MPI Moleculare Genetik fax :0049-(0)30-8413-1139 |
2008 Dec 05
2
Help with wavCWTPeaks
I cannot understand the following error printed out when I try to get the extrema of my time series.
I would appreciate some suggestion as I really cannot interpret the error. I might not be using a proper
set of parameters in calling such functions. I am learning by doing ...
> aa.peak <- wavCWTPeaks (aa.tree)
Error in `row.names<-.data.frame`(`*tmp*`, value = c("1",
2014 Apr 08
2
Test de Moses
¿Alguien sabe si el test de reacciones extremas de Moses está escrito en
algún paquete de R?
Gracias de antemano.
2012 Dec 12
3
create a color palette with custom ranges between colors
...nal
means,...).
I would like to create a color palette which works for each map, so I need a
color palette between -40 and +40?C. Sometimes my data for one map range
from -10 to +20, sometimes from 10 to 30, etc... but always between -40 and
+40?C.
I would like a fluent color gradation between my extremas (-40 and +40),
with different colors between customed values.
For example, if the temperature is under -20?C I would like the color
"darkblue", then if the temperature is between -20 and 0?C I would like the
color "lightblue", then between 0 and 20?C the color "yellow"...
2012 Nov 09
1
Breakpoints and non linear regression
...is a periodic function to be
fitted to a non linear model, but where no breakpoints should occur.
So basically, the breakpoints would only happen in the (a,b) pair of
coefficients, which would be a linear regression. However, as f is unknown,
this makes things harder and I don't have a lot of extremas (min/max) to
detect breakpoints robustly...
2) To detect breakpoint with an harmonic model and then to apply my non
linear regression on each segment.
These two ideas could potentially work, however these are workarounds.
Thank you for your advices !
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2007 Mar 12
1
How to avoid a for-loop?
Hi all,
as I am trying to move slowly from just "working" to "good" code, I'd
like to ask if there's a smarter way than using a for-loop in tasks like
the example below.
I need to obtain the extrema of the cumulated sum of a detrended time
series. The following code is currently used, please have a look at the
comments for my questions and remarks:
system.time({
X
2007 Jan 04
1
problem with function 'optimise' (PR#9438)
Full_Name: Karsten Krug
Version: 2.4.0
OS: Open Suse 10.0, Windows XP
Submission from: (NULL) (88.134.13.50)
I found a problem in the 'optimise' function for one dimensional optimisation.
Example 1:
Try to find a maximum of the function below with the use of 'optimise' in the
interval [0,0.5]. The function follows a parabola and has two local maxima
located at the margins of
2003 Aug 04
3
Breusch-Godfrey Test
> Dear R Helpers!
>
> bgtest{lmtest} performs the Breusch-Godfrey test for higher
> order serial
> correlation.
>
> Is the Higher Order Correlation function already programmed in
> R I couldn't find it?
>
> Sergei Petrov
>
?acf
?pacf
HTH,
Bernhard
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2010 Apr 12
0
WMTSA "wavCWTPeaks" : Error in if (time.start < times.range[1]) time.start <- times.range[1]
I have attached the signal that causes the error message in this email subject.
Only columns 1 and 3 have to be considered. It is the work trajectory of a molecule migrating between two equilibrium conformations.
The curve has 2 peaks, as shown in its plot. But I keep missing the 2nd one. Here is my short script:
library(wmtsa)
setwd("C:/Documents and Settings/Monville/Alanine
2008 Dec 12
0
Is there anyone in charge of package wmtsa ?
Here is another occurrence of wmTSA internal error.
My time series is a short breathing cycle (2425-Cyle_9.txt).
Since wmtsa functions that extract extrema seem to expect longer series than I have, I tried the folowing two tricks:
1) I prolong the 1-cycle series on both ends through duplicating the first value (on the left end( and the last value on the right end as any ties as the
1-cycle
2010 Mar 24
0
package "wmtsa": how to set up the Tolerance vector to detect time series peaks blindly
In my previous experience with wmtsa function wavCWTPeaks I realized the Tolerance vector passed to the multi-scale decomposition function "wavCWTTree" is crucial for detecting the time series extrema and prevent the R script from aborting.
By trial & error I recently managed to figure out the Tolerance vector values in a single case (please see attachments).
I am looking for some
2010 Feb 12
0
Found some nice knives with great prices and free shipping
Hey, I found some fantastic looking knives with great prices and free shipping. The website is www.liangdianup.com and these LDU Company people have bayonet knives, folders, switchblades, out the front knives, butterfly knives, and a bunch more. The web address for all of the knives is http://www.liangdianup.com/knives_1.htm
I like the all black Extrema Ratio bayonet knife the best but I also like
2007 Jul 10
2
integration over a simplex
Hello
The excellent adapt package integrates over multi-dimensional
hypercubes.
I want to integrate over a multidimensional simplex. Has anyone
implemented such a thing in R?
I can transform an n-simplex to a hyperrectangle
but the Jacobian is a rapidly-varying (and very lopsided)
function and this is making adapt() slow.
[
A \dfn{simplex} is an n-dimensional analogue of a triangle or
2012 Sep 19
0
Lowest AIC after stepAIC can be lowered by manual reduction of variables (Florian Moser)
A few general comments about stepwiseAIC and a suggestion of how to select models
a) Apart form the problem, that stepwise selection is not a garanty to get the best model, you need to have a lot of data to avoid overfitting if your model includes 7 parameter plus interactions (> 10 observations per parameter is what you are ideally looking for).
b) Have a look at Anderson and Burnham's
2006 Jun 08
3
Re-binning histogram data
Hi,
Short Version:
Is there a function to re-bin a histogram to new, broader bins?
Long version: I'm trying to create a histogram, however my input-data is
itself in the form of a fine-grained histogram, i.e. numbers of counts
in regular one-second bins. I want to produce a histogram of, say,
10-minute bins (though possibly irregular bins also).
I suppose I could re-create a data set as
2012 Feb 04
5
Comparaciones múltiples en ANOVA anidadp
Dispongo de un experimento en el que cinco tratamientos ha sido
aplicados a cinco grupos de voluntarios.
En cada grupo había tres personas y a cada persona se le tomaron 3 medidas,
En total dispongo de 45 medidas, pero evidentemente no son
independientes entre sí. Si no tomo en cuenta que las medidas de la
misma persona son más parecidas entre sí (bloques anidados) estaría
incurriendo en