Displaying 20 results from an estimated 2000 matches similar to: "Need help to optimize a piece of code involving zoo objects"
2009 Jun 19
1
(FULL) Need help to optimize a piece of code involving zoo objects
(Sorry, sent the message before I finished it)
Hello, everyone
I have a long script that uses zoo objects. In this script I used
simple moving averages and these I can very efficiently calculate with
filter() functions.
Now, I have to use special "exponential" moving averages, and the only
way I could write the code was with a for-loop, which makes everything
extremely slow.
I don't
2011 Sep 27
2
Coercing a character zoo to a numeric
Dear R-helpers,
It seems to me that a character zoo cannot be coerced to a numeric zoo.
Below is a minimal example. Can someone tell me what I have done wrong?
> z<-zoo(1:4,order.by=1:4)
> coredata(z)<-as.character(coredata(z))
> str(z)
‘zoo’ series from 1 to 4
Data: chr [1:4] "1" "2" "3" "4"
Index: int [1:4] 1 2 3 4
>
2006 Nov 29
2
problem with indexing a zoo object
My problem is the following : I create 2 zoo objects and then I try to
subset one of them using logic. indicesthatpass is a vector of trues and
falses but when I send it into bckret, it returns an empty bckret.
Obviously it has something to do with bckret being a zoo object and if I
do the same subsctripting off of coredata(bckret), I'm confident it will
work. But, I need to keep the minute
2006 Nov 23
1
Problem with as.ts(zoo-object)
Dear all,
I have an error message, when I try to convert a zoo object (called
test) to ts (on R 2.4.0, Package zoo version 1.2-1, Windows XP)
> test
1994-05-10 1994-06-09 1994-07-09
0.0024943889 0.0024881824 0.0006955831
> str(test)
atomic [1:3] 0.002494 0.002488 0.000696
- attr(*, "index")=Class 'Date' num [1:3] 8895 8925 8955
> is.regular(test)
[1] TRUE
2011 Jan 30
1
SMA and EMA in package TTR
Hi,
Just wondering for the SMA and EMA in package TTR, is it possible to me to
code it so that, say if I need to calculate SMA (x, n=100), when the sample
size is less than 100, it will give me the SMA (x, k) where k is the sample
size of the data? Right now it only gives me an invalid n error.
Thanks!
[[alternative HTML version deleted]]
2008 Oct 22
1
R 2.8.0 qqnorm produces error with object of class zoo?
Dear list-reader,
by running the following script:
library(zoo)
sessionInfo()
search()
packageDescription("zoo")
data(EuStockMarkets)
dax <- as.zoo(EuStockMarkets[1:10, "DAX"])
daxr <- diff(log(dax))
identical(as.vector(qnorm(daxr)), qnorm(coredata(daxr)))
qqnorm(coredata(daxr))
qqnorm(daxr)
qqnorm() produces an error:
> qqnorm(daxr)
Fehler in if (xi == xj) 0L
2011 May 05
1
quantmod's addTA plotting functions
Hi,
I'm having trouble with quantmod's addTA plotting functions. They seem to
work fine when run from the command line. But when run inside a function,
only the last one run is visible. Here's an example.
test.addTA <- function(from = "2010-06-01") {
getSymbols("^GSPC", from = from)
GSPC.close <- GSPC[,"GSPC.Close"]
GSPC.EMA.3
2012 Jun 06
2
package zoo, function na.spline with option maxgap -> Error: attempt to apply non-function?
Hello,
I'm trying to use na.spline (package zoo) to fill some missing data in a time series.
this works fine, however, if I apply the 'maxgap' argument, I always get the error:
<------
Error in na.spline.vec(x., coredata(object.), xout = xout., ...) : attempt to apply non-function
------>
I couldn't find a similar error for this case in the mailing lists and zoo vignette,
2010 May 11
3
Smoothing Techniques - short stepwise functions with spikes
R Friends,
I have data from which I would like to learn a more general
(smoothened) trend by applying data smoothing methods. Data points
follow a positive stepwise function.
| x
x
| xxxxxxxx xxxxxxxx
| x x
|xxxx xxx xxxx
| xxxxxxxxxxxxxxxxx
|
|
2011 Jan 24
2
how to slice a zoo object
Hi
Would anyone have any pointers on how to slice up a large zoo table. I
have the following structure: -
> str(ZOO_OBJ)
?zoo [1:632, 1:83] 30.4 30.4 30.4 30.4 30.3 ...
?- attr(*, "dimnames")=List of 2
??..$ : NULL
??..$ : chr [1:83] "COL1" "COL2" "COL3" "COL4" ...
?- attr(*, "index")= POSIXct[1:632], format: "2009-05-01
2000 Feb 28
1
Parser Bug Somewhere.... (PR#460)
Full_Name: John P Cavanaugh
Version: .99
OS: linux
Submission from: (NULL) (24.116.10.99)
dataset$ema12 <- EMA (dataset$Close,12)
dataset$ema26 <- EMA (dataset$Close,26)
dataset$MACD_fast <- dataset$ema26 - dataset$ema12
dataset$MACD_slow <- EMA(dataset$MACD_fast,9)
dataset$MACD_hist <- dataset$MACD_fast - dataset$MACD_slow # This line doesnt
work!!!
But... if I does work if I
2008 Sep 25
3
OHLC Plot with EMA in it
Hi there
I have some timeseries data which I plot in a OHLC Plot. In the same
plot I'd like to have the EMA of this timeseries. I tried to add the
EMA point to OHLC with lines(), but this doesn't work. Has anyone an
idea how to handle it?
Regards, Michael Zak
2012 May 21
1
Need help in doing EMA(Exponential Mean Average).
Can somebody help me in finding package/Example in R which could do
EMA(Exponential Mean Average).
I installed "TTR" package but the 'EMA" function which I was trying to use
is giving the following error.
Error: Could not find function "EMA"
Thanks & Regards,
Thomas
[[alternative HTML version deleted]]
2012 Apr 05
1
is parallel computing possible for 'rollapplyr' job?
Hi,
The code below does exactly what I want in sequential mode. But, it is slow and I want to run it in parallel mode. I examined some windows version packages (parallel, snow, snowfall,..) but could not solve my specific problem. As far as I understood, either I have to write a new function like sfRollapplyr or I have to change my code in a way that it utilizes lapply, or sapply instead of
2023 Apr 12
1
converting a character matrix into numeric....
Dear Rui,
Not working. I have entirely removed the column containing % but am still bootless:
> head(coredata(INFYTX))
INFY Historical Data INFY Historical Data INFY Historical Data INFY Historical Data
[1,] "47.26" "44.28" "47.56" "44.28"
[2,] "46.30" "44.92"
2023 Apr 12
1
converting a character matrix into numeric....
Dear members,
I have an xts object:
> head(INFYTX)
INFY Historical Data INFY Historical Data.1 INFY Historical Data.2
2003-04-16 "47.26" "44.28" "47.56"
2003-04-17 "46.30" "44.92" "46.53"
2003-04-21 "45.82"
2023 Apr 12
1
converting a character matrix into numeric....
?s 19:57 de 12/04/2023, akshay kulkarni escreveu:
> Dear members,
> I have an xts object:
>
>> head(INFYTX)
> INFY Historical Data INFY Historical Data.1 INFY Historical Data.2
> 2003-04-16 "47.26" "44.28" "47.56"
> 2003-04-17 "46.30" "44.92"
2023 Apr 12
1
converting a character matrix into numeric....
Isn't this like trying to tie up the horse after it has left the barn? Why not figure all this out _before_ converting to xts?
On April 12, 2023 12:29:49 PM PDT, akshay kulkarni <akshay_e4 at hotmail.com> wrote:
>Dear Rui,
> Not working. I have entirely removed the column containing % but am still bootless:
>
>> head(coredata(INFYTX))
> INFY
2011 May 07
2
Convenience-at-the-expense-of-clarity (was: quantmod's addTA plotting functions)
Thanks, Writing plot(addTA()) worked fine.
I find myself with such mixed feelings about R. After finding that addTA
worked fine at the command line but not in a function, I puzzled for a long
time about what kind of virtual machine structure could possibly account for
that. I couldn't think of any.
It turns out that this isn't due to an R virtual machine structure. The
reason addTA adds
2007 Mar 31
1
Problem with S4 inheritance: unexpected re-initialization?
Dear all,
To explain my problem I am attaching a demonstration package "myclasspkg":
I have the following two S4 classes with similar inheritance:
SubSubClassA <- SubClassB <- BaseClass
SubSubClassB <- SubClassB <- BaseClass
In R I am calling the following functions:
> library(myclasspkg)
> subA <-