Displaying 20 results from an estimated 5000 matches similar to: "How to calculate mean of every nth time series data with zoo or xts ?"
2012 Jul 29
1
readRDS, In as.double.xts(fishReport$count) : NAs introduced by coercion
Hello,
I looked in the R-help but could not find an archive addressing the
following. I would like to convert a character to numeric after reading a
file with RDS extension. After using as.numeric, I checked if it is
numeric. It was not converted. Please help.
Here is my code
>Report <- readRDS(file="RDS/Report.RDS")
> Report[1:2,]
dive_id date
2010 Nov 05
1
as.xts
hey
I am trying to turn a dataframe into xts with the function:
as.xts,
but it returns the error:
Error in as.POSIXlt.character(x, tz, ...) :
character string is not in a standard unambiguous format
could someone give me some pointers please
the data is coming from a spreadsheet via the excel, and has 5 columns
of data (date (with the date and time), open, high, low, close) (excel
format)
ela
2011 Oct 21
2
plotting with a symbol on every nth point
Hi,
I would like to produce a plot with a symbol on every nth point in a time
series data, like the one in the following:
http://www.phon.ucl.ac.uk/home/yi/ProsodyPro/EnglishFocus.png
x <- seq(-100,1000,25)
plot(x,type="l")
Could someone help me out with the above example?
Thanks....
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2005 Oct 25
1
selecting every nth item in the data
I want to make a glm and then use predict. I have a fairly small sample
(4000 cases) and I want to train on 90% and test on 10% but I want to do
it in slices so I test on every 10th case and train on the others. Is
there some simple way to get these elements?
Stephen
--
21/10/2005
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2012 Apr 05
3
Apply function to every 'nth' element of a vector
Dear R users,
how do I e.g. square each second element of a vector with an even
number of elements? Or more generally to apply a function to every
'nth' element of a vector. I looked into the apply functions, but
found no hint.
For example:
v <- c(1, 2, 3, 4)
mysquare <- function (x) { return (x*x) }
w <- applyfun(v, mysquare, 2)
then w should be c(1, 4, 3, 16)
Thanks for
2008 Feb 25
1
Plotting series marked with a symbol on every nth data point, preferably in ggplot...
Hello!
I am working with signals and a plot of several signals on the same
axes can get quite messy. With lines that are very fractured,
distinction by only the linestyle is not very clear. If I add symbols
to the plot however, there are so many symbols, that they overplot and
the whole plot is unreadable once again. I am looking for advice on
how to make a plot with continuous lines and symbols
2001 Mar 28
4
How to extract every nth element from a vector
R-helpers:
Is there a simple way to extract every nth element from a very long vector?
[The vector I want to sample from is an object returned by lowess(). It is
so long (11,628 pairs of elements) that it is causing non-R-related memory
problems elsewhere. I don't see a better way other than sampling the output
returned from lowess.]
Thanks in advance.
Barry Cooke
2010 May 17
1
Isn't aggreate.zoo supposed to work with POSIXct (zoo/TTR/xts issue)?
library(xts)
library(TTR)
ndx = getYahooData("^NDX")
aa = ndx$Close
bb = aggregate(aa, as.yearweek, tail, 1)
The last operation takes forever, and then the bb dates are messed up. The following produces the desired result:
time(aa) = as.Date(time(aa))
bb = aggregate(aa, as.yearweek, tail, 1)
The index of ndx and aa is of POSIXct (as reported by is(time(ndx))) , which apparently
2011 Mar 02
1
Create a zoo/xts Time Series with Millisecond jumps
Is there a easy way to create the time index for a zoo/xts object for every
100 milliseconds.
eg. time Index would be:
10:00:00:100
10:00:00:200
10:00:00:300
10:00:00:400
I am looking to build an empty zoo/xts object with time index from 10am to
3pm, index jumps by 100ms each row.
Thanks,
Chris
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2009 Sep 25
0
differing behaviour between xts (0.6-7) and zoo (1.5-8)
Folks,
I have some weekly dataseries that I convert to monthly xts (with
yearmon indices), and obtain the two following extracts:
> str(sig)
An 'xts' object from Apr 1998 to Sep 1998 containing:
Data: num [1:6, 1] 0.0083 0.2799 -0.2524 -0.0119 0.18 ...
- attr(*, "dimnames")=List of 2
..$ : NULL
..$ : chr "e1"
Indexed by objects of class: [yearmon] TZ:
2017 Oct 06
2
Time series: xts/zoo object at annual (yearly) frequency
Hi,
I'd like to make a time series at an annual frequency.
> a<-xts(x=c(2,4,5), order.by=c("1991","1992","1993"))
Error in xts(x = c(2, 4, 5), order.by = c("1991", "1992", "1993")) :
order.by requires an appropriate time-based object
> a<-xts(x=c(2,4,5), order.by=1991:1993)
Error in xts(x = c(2, 4, 5), order.by =
2010 Jan 14
0
chron, xts and zoo
dear r folks
i am a bit puzzled about how to use chron as an index xts and why it differs
from zoo.
in this example, why can i index zoo but not xts
x<-1:23
time.of.day <- times(paste(x,":0:0",sep=""),format="h:m:s")
day <- dates("4/8/90")
period <- chron(dates=day,times=time.of.day)
xts(1:23,period)
zoo(1:23,period)
i suspect it might be to
2011 May 28
1
How to do operations on zoo/xts objects with Monthly and Daily periodicities
Is there an elegant way to do operations (+/-/*/ / ) on zoo/xts objects when
one serie is monthly (end of month) and the other daily (weekdays only) -
typically a monthly economic indicator and a stock index price?
Thanks,
TDB
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2011 Jan 23
1
Plotting multiple xts/zoo time series on a single plot.
So I've got a 154 column wide xts time series object and I want to plot the
154 series on a single plot and have the added benefit of the time series
dates on the x axis.
Any suggestions for plotting functions, maplot works but does not give dates
on the axis and I can't seem to get plot to give me more than one series.
Nick
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2012 Nov 27
2
Books for fully understanding internal logics on some packages(quantmod, xts, zoo and chron)
Hello,
I'm very interested in using financial time series data, but I'm a beginner of R programming.
I'd like to fully understand internal logics on several time-series related packages such as quantmod, xts, zoo, chron, etc.
So, I read some books, 'R Cookbook' and 'Art of R Programming' and another simple tutorials.
But I still can't understand grammars of the
2012 Apr 23
2
subset daily to monthly in a zoo or xts
Dear R users,
I want to subset a daily zoo series according to its month, find % of "NA"
in each month.
I am finding it difficult to subset the daily dataset into monthly for the
given operation.I am planning to do this for a huge dataset.
Thanks in advance.
Regards
Vikram
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2010 Apr 20
1
converting a zoo or an xts to a data frame
Dear R People:
I have the following code that I use to convert a monthly zoo object
to a data.frame, and it works perfectly:
library(tseries)
z <- get.hist.quote(instrument=inst1, start=start1,end=end1,
quote=quot1,comp = "m")
y <- as.ts(aggregate(z, as.yearmon, tail, 1))
y.df <- data.frame(y=y,time=time(y))
y.df$x <- ts(y.df[,1])
tsp(y.df$x) <-
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
2010 Apr 18
4
confused with yearmon, xts and maybe zoo
R-listers,
I am using xts with a yearmon index, but am getting some inconsistent
results with the date index when i drop observations (for example by using
na.omit).
The issue is illustrated in the example below. If I start with a monthly
zooreg series starting in 2009, yearmon converts this to "Dec-2008". Not
such a worry for my example, but strange. Having converted to xts, i drop
2013 Jan 04
2
Can you help me please
HI Fares,
You could try this:
dat1<- read.table(text="
date????? donation
3jan2003?? 20235
4jan2003?? 25655
5jan2003?? 225860
6jan2003?? 289658
7jan2003?? 243889
8jan2003?? 244338
9jan2003?? 243889
",sep="",header=TRUE,stringsAsFactors=FALSE)
The post is not very specific as to what you need.? I hope this works for you.
library(xts)