search for: extrema

...ge 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(), I managed to find one obvious speedup (switching from employing rbind() to c()) and I suspect that there may be a way to further speed things up by pre-allocating all the objects that are currently being created with c(), but I'm having trouble understa...

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 |

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(&qu...

¿Alguien sabe si el test de reacciones extremas de Moses está escrito en algún paquete de R? Gracias de antemano.

...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&quo...

...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 ! -- View this message in context: http://r...

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 <- rnorm(10000) X.length <- length(X) X.cum.sum <- cumsum(X) X.cum.mean <- cummean(X)...

...type="l") abline(v=opt1$maximum, col="red") The returned value of the maximum is 0.309017 which is definitely wrong. Example 2: The next function has also two equivalent maxima this time not located at the margins of the interval [0, 9/41]. Thus, the maxima are real analytic extrema. The function 'optimise()' again returns a wrong value. ex2 <- function(x) log((18/41) * x - 2 * x^2) + 16 * log(4 * x^2 - (36/41) * x + (9/41)) + 24 * log((23/82) + (18/41) * x - 2 * x^2) opt2 <- optimise(ex2, lower=0, upper=(9/41), maximum=T) x <- seq(0,9/41,0.001) plot(x,...

> 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 ---------------------------------------------------------------------- If you have received this e-mail

...sqrt(scales)) > summary(work.tree) End Time Length Octaves Min Max Mean SD Var MAD 1 1043 78 11.7 -6.4e-09 1957560 362197 626303 3.92e+11 0.0533 > work.peak <- wavCWTPeaks(work.tree) > attr(work.peak,"peaks") branch itime iscale time scale extrema iendtime 1 1 1238 64 1238 995 1957560 1043 What am I doing wrong ? Please, explain Thank you very much. Maura e tutti i telefonini TIM! Vai su

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 series length. Then I apply CWT to such prolonged series and...

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 criteria, possibly based on the CWT results, to make this choice automatic. Any suggestion and/or comment is wel...

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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

...the moment (count data of two species, host and herbivore): 1) I checked which of my parameters explained the abundance of the species , using GLMs and bootstrapping of an LR-test to check if the model with the parameter is better than one without the parameter ( one way to deal with outliers and extrema) 2) Then I build all combinations of those parameters, that predicted the two species well (p-values <0.05, and >95% sucessfull bootstrapping). 3) I wrote down all the multiple models with decent p-values and calculated AICc ( AICc is for small data sets, and should be used anyway as for ve...

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

...podría haber utilizado las funciones lme del paquete nlme o lmer del paquete lme4, pero tampoco proporcionan objetos válidos para glht o TukeyHSD. ¿Alguien sabe como abordar las comparaciones múltiples con medidas repetidas o anova anidado? Gracias de antemano. -- _____---^---_____ Univ. de Extremadura Dept. Matemáticas. Despacho B29 Tf: + 34 924 289 300 Ext. 86823