Displaying 20 results from an estimated 10000 matches similar to: "Indexing zoo objects"
2009 Sep 24
2
Date formats in as.Date
I have trouble with this:
as.Date("Sep-1981", format="%b-%Y")
Returns "NA"
>From documentation for strftime
'%b' Abbreviated month name in the current locale. (Also matches
full name on input.)
'%Y' Year with century.
What am I doing wrong?
cheers
Worik
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2010 Dec 30
2
optim and singularity
Hello,
I was unable to find clues to my problem in ?optim. Using the data and code
below, I get an error ("system is exactly singular") when a particular line
of code is left in, but have found that 'optim' works when I comment it out.
The line of code in question is after the closeAllConnections() line of code
and contains a call to "na.approx" from the zoo package.
2012 Mar 25
2
Weird POSIXct behaviour
Friends
I have an xts that I wish to access.
Browse[2]> DATA.ba[[p]]["2012-03-20 00:59:57","bid"]
bid
2012-03-20 00:59:57 1.4993
So far so good.
Now putting the index into a variable:
Browse[2]> Time
[1] "2012-03-20 00:59:57 NZDT"
Browse[2]> DATA.ba[[p]][Time, "bid"]
bid
Where has it gone?
Looking closer....
2011 Nov 11
3
Why does length("") == 1?
It seems obvious to me that the empty string "" is length 0.
cheers
Worik
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2008 Apr 23
1
Time arithmetic
I am a bit worried I am reinventing the wheel. Isn't there a calendar
system in R?
I have written a function to add months to a date and return the number of
days resulting. I am newish to R so I am hoping there is a package that
can do this sort of date arithmetic for me...
Worik
DaysInMonths <- function(s,d){
## Days in d months from s
sdate <- MSTD(s)
## Get day, month
2010 Jun 16
5
t-test problem
I have two pairs of related vectors
x1,y1
and
x2,y2
I wish to do a test for differences in means of x1 and y1, ditto x2 and y2.
I am getting odd results. I am not sure I am using 'pt' properly...
I have not included the raw vectors as they are long. I am interested if I
am using R properly...
> c(length(x1), length(y1), length(x2), length(y2))
[1] 3436 1619 2677 2378
First
2012 Oct 09
4
Modern Symbolic debugger for R programmes?
I think I am whistling in the wind, but is there a modern symbolic
debugger for R programmes?
I am working through some one else's code, thousands of lines, that
has the occasional bug in it, and a lot in my understanding of it.
I cannot make setBreakpoint or findLineNum work. I get "No source
refs found.". I am starting to loose my mind!
A debugger where I could set
2011 Apr 08
5
Avoiding a loop
Friends.
I cannot simplify this much, and I think the loop is unavoidable. As a
recovering C programmer I want to avoid loops and in cases like this I
almost allways can by using an apply function. But I suspect in this case
there is nothing I can do.
It is a finance example where a price series is compared to a moving
average. If the price goes above the average, plus a bit, buy the
2010 Feb 17
2
extract the data that match
Hi r-users,
I would like to extract the data that match. Attached is my data:
I'm interested in matchind the value in column 'intg' with value in column 'rand_no'
> cbind(z=z,intg=dd,rand_no = rr)
z intg rand_no
[1,] 0.00 0.000 0.001
[2,] 0.01 0.000 0.002
[3,] 0.02 0.000 0.002
[4,] 0.03 0.000 0.003
[5,] 0.04 0.000 0.003
[6,]
2010 Jun 13
2
Scope and sapply
I am puzzled by the scope rules that apply with sapply.
If I want to modify a vector with sapply I tried...
N <- 10
vec <- vector(mode="numeric", length=N)
test <- function(i){
vec[i] <- i
}
sapply(1:N, test)
vec
but it not work.
How can this be done?
Worik
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2012 Apr 19
2
Trouble with [sv]apply
Friends
I clearly donot understand how sapply and vapply work.
What I have is a function that returns a matrix with an indeterminate
number of rows (some times zero) but a constant number of columns. I
cannot reliably use an apply function to assemble the matrices into a
matrix. I am not sure it is possible.
I can demonstrate the core of my confusion with this simple code.
A.f <-
2012 Nov 30
3
Line numbers with errors and warnings?
Is it possible to get a line number with an error report?
I have a long script and an error:
Error in `[.xts`(x, xsubset) : subscript out of bounds
It would be very helpful, and save a lot of time, if there was some
indication in the error message which line the error was.
I can find it using binary search but that is a painful process.
cheers
Worik
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2011 May 08
2
Pretty printing numbers
Friends
I am trying to format a number to a string so 2189.745 goes to "2,189.35"
and 309283.929 goes to "309,283.93"
I have tried to use formatC(X, big.mark=",",drop0trailing=FALSE, format="f")
but it does not get the number of decimals correct. Specifying digits does
not work as that is significant digits. I could use a switch statement
switching on
2011 Sep 13
1
Getting Rcpp SEXP data in C++
Friends
I am looking at Rcpp and I am a bit stuck on a simple matter.
(I am calling R from c++, if there is a better way...)
Given this simple example using the TTR package and the SMA function which
returns a simple moving average....
Rcpp::NumericVector rv;
for(int i = 0; i < 100; i++){
rv.push_back(rand());
}
Rcpp::Environment TTR("package:TTR");
2010 Mar 18
1
Locating an error
I have a large programme that after running half an hour or so fails with an
error
Error in x[value] <- NA : only 0's may be mixed with negative subscripts
How can I find out where that error occurs?
If I have to do a binary search using error messages it will take a long
time! Is there some way I can generate a stack trace?
cheers
Worik
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2008 Apr 23
2
Incrementing Dates
How can I increment the value of a Date class?
I want to add a day, month or year to a date.
cheers
Worik
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2010 Jun 08
2
Logical vector question
If I create a vector thusly
> v1 <- runif(20, min=0, max=1)
> v1
[1] 0.9754443 0.6306228 0.3238158 0.3175769 0.6791534 0.6956507 0.3840803
[8] 0.1421328 0.8592398 0.4388306 0.9472040 0.4727435 0.5645302 0.7391616
[15] 0.6116199 0.2727754 0.2657867 0.5261744 0.8764804 0.2032126
And I want to create a logical vector the same length that is true if v1<.3
or v1 > .7 how do I do it
2011 Sep 02
2
Advice on large data structures
Friends
I am starting on a (section of the) project where I need to build a matrix
with on the order of 5 million rows and 200 columns
I am wondering if I can stay in R.
I need to do rollapply type operations on the columns, including some that
will be functions of (windows of) two columns.
I have been looking at the ff and bigmemory packages but am not sure that
they will do.
Before I get
2009 Sep 02
2
Help with sub-setting data.frame
Friends
I have a data frame, df that I want to extract some rows from
Here is a sample of the data
> head(df)
TDate Expiry Underlie Strike CSettle PSettle Futures ExDate
TTE
1 20080102 200801 200803 0.840 0.0000 0 0.9207 20080104
0.005479452
2 20080102 200801 200803 0.850 0.0000 0 0.9207 20080104
0.005479452
Rate Disc
1 0.0457 0.9997496
2 0.0457
2008 Apr 23
1
difftime result in years?
I would like to know how many years (including partial years) are between
two dates.
So difftime("20/11/1962", "20/5/1964", units="years") would be about 1.5
But units of years are not available.
cheers
Worik
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