Displaying 20 results from an estimated 2000 matches similar to: "How to compute Rolling analysis of Standard Deviation using ZOO package?"
2010 Jan 17
1
Confusion in 'quantile' and getting rolling estimation of sample quantiles
Guys:
1).When I using the 'quantile' function, I get really confused. Here is what
I met:
> x<-zoo(rnorm(500,0,1))
> quantile(x,0.8)
400
1.060258
> c=rnorm(500,0,1)
> quantile(c,0.8)
80%
0.9986075
why do the results display different? Is that because of the different type
of the class?
2).And I want to use the 'rollapply' function to compute a
2011 Jan 30
3
How to do a moving window on standard deviation
I'd like to use vectorization to take a 4 point moving window on standard
deviation on the close column and create another variable (st.dev) in the
dataframe. Here's the dataframe
head(xyz)
Date Close
1 2011-01-28 56.42
2 2011-01-27 57.37
3 2011-01-26 56.48
4 2011-01-25 56.39
5 2011-01-24 55.74
6 2011-01-21 55.46
So the first 3 elements to the new st.dev column would be zero
2017 Aug 10
2
Zoo rolling window with increasing window size
Hi again,
I am wondering there is any function for 'zoo' time series, where I
can apply a user defined function rolling window basis, wherein window
size is ever increasing i.e. not fixed. For example, let say I have
below user defined function and a zoo time series :
> library(zoo)
> UDF = function(x) sum(x)
> TS = zoo(rnorm(10), seq(as.Date('2017-01-01'),
2011 Aug 12
2
rollapply.zoo() with na.rm=TRUE
Hi.
I'm comparing output from rollapply.zoo, as produced by two versions
of R and package zoo. I'm illustrating with an example from a R-help
posting 'Zoo - bug ???' dated 2010-07-13.
My question is not about the first version, or the questions raised in
that posting, because the behaviour is as documented. I'm puzzled as
to why na.rm no longer is passed to mean, i.e. why
2010 Jul 13
2
Zoo - bug ???
Hi folks,
I am confused whether the following is a bug or it is fine
Here is the explanation
a <- zoo(c(NA,1:9),1:10)
Now If I do
rollapply(a,FUN=mean,width=3,align="right")
I get
> rollapply(a,FUN=mean,width=3,align="right")
3 4 5 6 7 8 9 10
NA NA NA NA NA NA NA NA
But I shouldn't be getting NA right ? i.e for index 10 I should get
(1/3)*(9+8+7)
2017 Aug 10
0
Zoo rolling window with increasing window size
Use a `width` of integer index locations. And you likely want =
"right" (or rollapplyr(), as I used).
R> set.seed(21)
R> x <- rnorm(10)
R> rs <- rollapplyr(x, seq_along(x), sum)
R> cs <- cumsum(x)
R> identical(rs, cs)
[1] TRUE
On Thu, Aug 10, 2017 at 1:28 PM, Christofer Bogaso
<bogaso.christofer at gmail.com> wrote:
> Hi again,
>
> I am
2011 Apr 03
1
zoo:rollapply by multiple grouping factors
# Hi there,
# I am trying to apply a function over a moving-window for a large
number of multivariate time-series that are grouped in a nested set of
factors. I have spent a few days searching for solutions with no luck,
so any suggestions are much appreciated.
# The data I have are for the abundance dynamics of multiple species
observed in multiple fixed plots at multiple sites. (I total I
2009 Jul 07
1
Error in Rolling window of function - rollapply
Dear Colleagues,
I have faced with the problem that function rollaply with rolling window for
calculation of volatility doesn't give the all results of calculations.
I have run the rolling window for calculation in Excel and obtained that the
number of outputs for Excel is 36 and for R is 18. The total number of
observations is 37. In the attachment you can find pdf of the Excel and
Excel
2017 Aug 10
3
Zoo rolling window with increasing window size
Hi Joshua, thanks for your prompt reply. However as I said, sum()
function I used here just for demonstrating the problem, I have other
custom function to implement, not necessarily sum()
I am looking for a generic solution for above problem.
Any better idea? Thanks,
On Fri, Aug 11, 2017 at 12:04 AM, Joshua Ulrich <josh.m.ulrich at gmail.com> wrote:
> Use a `width` of integer index
2017 Aug 10
0
Zoo rolling window with increasing window size
Replace "sum" with your custom function's name. I don't see any
reason why that wouldn't work, and the problem with my solution is not
clear in your response.
r <- rollapplyr(x, seq_along(x), yourCustomFunctionGoesHere)
On Thu, Aug 10, 2017 at 1:39 PM, Christofer Bogaso
<bogaso.christofer at gmail.com> wrote:
> Hi Joshua, thanks for your prompt reply. However
2012 Jan 24
1
problems with rollapply {zoo}
Here is a relatively simple script (with comments as to the logic
interspersed):
# Some of these libraries are probably not needed here, but leaving them in
place harms nothing:
library(tseries)
library(xts)
library(quantmod)
library(fGarch)
library(fTrading)
library(ggplot2)
# Set the working directory, where the data file is located, and read the
raw data
2009 Mar 23
1
performance: zoo's rollapply() vs inline
zoo's rollapply() function appears to be extremely useful for plugging in a
function on-the-fly to run over a window. With inline, there is a lot more
coding and room for error, and the code is less portable because the user
has to have R compiling set up or it won't work.
However, rollapply() seems to be really slow. Several orders of magnitude
slower than inline, in fact. I don't
2008 Aug 21
1
max and min with the indexes in a zoo object (or anything else that could solve the problem)
library(zoo)
library(chron)
t1 <- chron("1/1/2006", "00:00:00")
t2 <- chron("1/31/2006", "23:45:00")
deltat <- times("00:15:00")
tt <- seq(t1, t2, by = times("00:15:00"))
d <- sample(33:700, 2976, replace=TRUE)
sin.zoo <- zoo(d,tt)
#there are ninety six reading in a day
d.max <- rollapply(sin.zoo, width=96, FUN=max)
2011 Nov 04
1
zoo performance regression noticed (1.6-5 is faster...)
Good morning,
I have discovered what I believe to be a performance regression
between Zoo 1.6x and Zoo 1.7-6 in the application of rollapply.
On zoo 1.6x, rollapply of my function over my data takes about 20
minutes. Using 1.7-6, the same code takes about 6 hours.
R --version
R version 2.13.1 (2011-07-08)
Copyright (C) 2011 The R Foundation for Statistical Computing
ISBN 3-900051-07-0
Platform:
2007 Nov 30
1
rollapply on zoo object
Dear R users.
I have zoo object "size_june" containing market-capital values:
> dim(size_june) # market-cap data of 625 firms for 20 years
[1] 20 625
> class(size_june)
[1] "zoo"
> size_june # colnames = "size.firmcode"
size.34020 size.4710 size.11050 size.10660 size.9540 size.8060
size.16160 size.8080 size.9280
1988-06-30 NA
2005 Apr 02
1
Survey of "moving window" statistical functions - still looking f or fast mad function
Hi,
First, let me thank Jaroslaw for making this survey. I find it quite
illuminating.
Now the questions:
* the #1 solution below (based on cumsum) is numerically unstable.
Specifically if you do the runmean on a positive vector you can easily
get negative numbers due to rounding errors. Does anyone see a
modification which is free of this deficiency?
* is it possible to optimize the
2011 Oct 03
2
rolling regression
Dear all,
I have spent the last few days on a seemingly simple and previously documented rolling regression.
I have a 60 year data set organized in a ts matrix.
The matrix has 5 columns; cash_ret, epy1, ism1, spread1, unemp1
I have been able to come up with the following based on previous help threads. It seems to work fine.
The trouble is I get regression coefficients but need the immediate
2005 Mar 02
2
apply a function to a rolling subset of a vector
Try this:
> ?convolve
> x<-rnorm(1000)
> y<-rep(1,20)
> z<-convolve(x,y,type="filter")
> plot(x,type="l")
> str(z)
num [1:981] 6.31 7.28 8.16 7.39 4.65 ...
> lines(c(rep(0,10),z,rep(0,10)),col="yellow",lwd=3)
> lines(c(rep(0,10),z,rep(0,10))/length(y),col="red",lwd=3) #running mean
You wrote:
Does anyone know an easy way
2010 Jan 13
1
Rollapply
Hi
I would like to understand how to extend the function (FUN) I am using in
rollapply below.
######################################
With the following simplified data, test1 yields parameters for a rolling
regression
data = data.frame(Xvar=c(70.67,70.54,69.87,69.51,70.69,72.66,72.65,73.36),
Yvar =c(78.01,77.07,77.35,76.72,77.49,78.70,77.78,79.58))
data.z = zoo(d)
test1 =
2008 Jul 29
1
rolling regression between adjacent columns
Hi everyone,
I am trying to apply linear regression to adjacent columns in a matrix (i.e.
col1~col2; col3~col4; etc.). The columns in my matrix come with identifiers
at the top of each column, but when I try to use these identifiers to
reference the columns in the regression function using rollapply(), the
columns are not recognised and the regression breaks down. Is there a more
robust way to