Displaying 20 results from an estimated 1000 matches similar to: "Question concerning "pastecs" package"
2007 Nov 19
0
Using density() and turnpoint to Identify maxima in data
Hi
I have a large dataset which follows a multimodal distribution. And I
would like to identify the maxima. As the data is obtained from a
stochastic simulation, not all maxima in the data are "real maxima of
the dirstribution" but rather small random fluctuations. Unfortunately,
it is not possible for me to run more simulations to smooth the obtained
distribution.
What I am doing
2011 Jan 04
1
function masking and gmp questions
Hi,
Here's the problem I ran into: the gmp package has a method for apply()
so it masks the base::apply function. With gmp installed, I tried to
run the function turnpoints() from the pastecs package. It fails
because it calls apply() internally, like this:
apply(mymatrix,1,max,na.rm=TRUE)
,
but the code in the gmp package which sets up the operator overload for
apply() strictly
2005 May 16
0
Turnpoints (pastecs): How to specify a limit on the number of tur npoints?
Hello,
I'm trying to get a few turnpoints for a financial time series. There is a
function in pastecs that does that. However, I get a large number of
turnpoints:
library(pastecs)
data(EuStockMarkets)
dax <-EuStockMarkets[,1]
plot(dax)
turnp <-turnpoints(dax)
summary(turnp) #gives 925 peaks/pits!!!
How can specify to get only 30 turnpoints?
Second question: the extract function
2006 Mar 15
1
Additional arguments in S3 method produces a warning
Hello,
I just notice this:
> x <- c(1:4,0:5, 4, 11)
> library(pastecs)
Loading required package: boot
> tp <- turnpoints(x)
> extract(tp, no.tp = FALSE, peak = TRUE, pit = FALSE)
[1] FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE TRUE FALSE
FALSE
Warning message:
arguments after the first two are ignored in: UseMethod("extract", e, n,
...)
>
2009 Sep 16
2
Turnpoints
Good evening to everybody. I have a data of four columns - three of the
columns represent date while the fourth is counts. Setting 4000 as my
minimum point/value, I wish to find out the number of counts that are less
or equal to 4000 and the dates they occur. I have installed pastecs and have
been trying to use turnpoints function to do this. I have not been much
lucky. I am a still learning. I
2002 Dec 29
3
lowess + turnpoints = doubling integers?
Happy New Year, r-helpers!
I am using lowess to smooth a scatter plot,
xx<-lowess(xinput,f=.04) #defaults for other args
followed by
turnpoints(xx$y) #defaults for other args
I plot the smoothed result as well as turnpoints (using yy$tppos) on top of raw
data plot.
Result is exactly as expected, graphically.
For another purpose, I calcuate the difference between turnpoints (representing
2009 Sep 18
1
Help a newbie
Hello,
To me as a beginner, every problem looks big. Below is what I was asked to
do as part of a code that will solve my problem. I have used read.table to
read my data into R and assigned the column names with colnames(dat)<- ... .
But to go from txt<-" to the last " at the bottom of the table below is what
I am unable to do. Could anybody please tell me how to type or arrive at
2009 Sep 17
1
Turning points in a series
Good morning once more. My problem of yesterday has been addressed. Having
learned a few tricks from that, I wish to ask another question in connection
with that. My data is a cosmic ray data consisting of dates and counts. When
I plot a graph of counts versus dates, the resultant signal shows a number
of maximum and minimum points. These minimum points (turning points) are of
interest to me.
2004 Mar 19
1
date conversions in pastecs
In function daystoyears in package pastecs, I get this (wrong?) result
with 1995:
> daystoyears(1,datemin="1/1/1997",dateformat="m/d/Y")
1997.001
> daystoyears(1,datemin="1/1/1995",dateformat="m/d/Y")
1994.999
Any insights?
Thanks
Angel
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 |
2004 Jun 18
2
[Q] Newbie (continued.. at least I got R running allready :-)
Hi all
a week ago, I posted a newbie question in data smoothing &
maximum-extraction with R. I got quite a lot of response, but I'm still
kinda stuck with it...
I'll restate the problem : i got a datafile with 2400 measuerements (every
250msec) of a CO2 measurement device, capturing the breath of a subject. I
uploaded such a sample here :
2006 Oct 27
0
problem with applying regul function (pastecs)
Hi,
I'm trying to analyse some time series data on dissolved organic
nitrogen. Because it has gaps in it, I try to interpolate (linear) with
the regul method from the pastecs package.
I have a number of stations with measurement series in a matrix
constructed from a data frame with the unstack method (temp)
I also used the unstack method to make a similar matrix for the time
points
2009 May 17
0
Some questions about package "pastecs" and "stats"
My goal is to remove signals trend without any a-priori knowledge of the trend type, if any. Some signals are very noisy and non-stationary (example attached).
I have experimented with a number of techniques. Staring at the results, I can hardly tell which method is best.
I am attaching the result of function "local.trend" as I cannot understand it. Nor I can make a sense of the returned
2001 Sep 10
3
Offline change detection methods?
Dear [R] people, I am looking for a method to test if there are any
changes (jump points) in a time series data set or not. If there are, I
would like to identify the jump points. All the data is available from the
beginning so an offline method could be used.
The current data set that I have could be seen as a time series with
five almost equally sized segments that stands out to have different
2010 Dec 14
3
peak detection
Hi,
I was wondering if anyone knows of a package that contains the ability
for peak/valley detection. Here is an example of what I'm looking for,
only problem is that it's written in Matlab.
http://www.billauer.co.il/peakdet.html
Thanks for any help in advance.
-Joe
2006 Jun 15
1
Question concerning mle
Hi
I hope this is the right forum - if not, point me please to a better one.
I am using R 2.3.0 on Linux, SuSE 10.
I have a question concerning mle (method="BFGS").
I have a few models which I am fitting to existing data points. I
realised, that the likelihood is quite sensitive to the start values for
one parameter.
I am wondering: what is the best approach to identify the right
2009 Sep 16
1
Registration
Hi,
I have a question to post. But I have a problem finding the appropriate
forum. Some of the FAQ on pastecs are answered by
R-help@stat.math.ethz.chmailing list. I searched to see if this
mailing list requires registration
or not. There was no information about that. I am a registered member of R-
help general mailing list but I am aware it is better to post my question to
a specific group in
2006 Mar 15
3
which.minimums not which.min
Hi
Is there a function which determines the location, i.e., index of the all minimums or maximums of a numeric vector.
Which.min(x) only finds the (first) of such.
> x <- c(1:4,0:5, 4, 11)
> x
[1] 1 2 3 4 0 1 2 3 4 5 4 11
> which.min(x)
[1] 5
> which.max(x)
[1] 11
>
but I need
which.min(x) to be 5 11
which.max(x) to be 4 10
2010 Dec 23
1
Finding flat-topped "peaks" in simple data set
Hello,
Thank you to all those great folks that have helped me in the past
(especially Dennis Murphy).
I have a new challenge. I often generate time-series data sets that look
like the one below, with a variable ("Phase") which has a series of
flat-topped peaks (sample data below with 5 "peaks"). I would like to
calculate the phase value for each peak. It would be great to
2013 Apr 24
2
How to make a raster image in R from my own data set
Hi R-user,
I was trying to make a raster map with WGS84 projection in R, but I could not make it. I found one data set in Google that data is almost the same format as of mine. I wanted to make a raster map of temperature with 1 degree spatial resolution for the global scale.
I could make it in GIS software but I do have many variables (to be many raster images) and ultimately I am importing them