Displaying 20 results from an estimated 7000 matches similar to: "Determining maximum hourly slope per day"
2008 Aug 02
1
problem with nested loop for regression
Hi everyone,
I'm experiencing difficulty getting the results I want when I use a nested
for loop. I have a data set to which I perform some calculations, and then
try to apply a regression over a rolling window. The code runs, but the
regression results I am getting (intercept and slope) are simply the same,
repeated again and again in the results matrix. The regression does not seem
to be
2009 Jul 11
2
Date conversions
Hi all,
I'm having a little bit of trouble with some date conversions and
am hoping someone can help me out. Thanks in advance.
OK, I have two sources of data that provide date info in a csv file
differently. I've attached a small zipped file with two text files
that illustrate both. (Is it ok to send attachments to this list? Not
sure. It's very small.) I need to be able to
2012 Nov 10
4
help on date dataset
Hi everybody,
I am beginer in R and I need your precious help.
I want to create a small function in R as in sas to retrieve date.
I have a file with data that import in R.
DATE PAYS nb_pays.ILI.
1 24/04/2009 usa 0
2 24/04/2009 usa 0
3 24/04/2009 Mexique 0
4 24/04/2009
2013 Feb 14
3
Problems plotting and regression w.r.t. date data type on x axis
Hello,
probably a newbie question, but i didnt find any information on
plotting/regressing w.r.t. a date data type. My trials were unfruitful. Can
anyone help ? Thanks in advance!
Here is my interaction with R:
> tabelle
date number date2
1 2009-01-1 1673 2009-01-01
2 2009-12-1 2111 2009-12-01
3 2010-7-1 2487 2010-07-01
4 2013-2-1 4301 2013-02-01
> regression.punkte<-lm(tabelle$number
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
2005 Feb 24
2
Row median of Date class variables in a data frame
I am trying to calculate the median of each row of a
data frame where the data frame consist of
columns of class Date.
Below are my test data and best attempt at using apply.
I didn't see a solution via Google or the Baron search
site.
I'd be grateful for any suggestions or solutions.
I'm using R 2.0.0 on Mac OS X.
Thank you,
Stephen Weigand
### Test data
date1 <- c(1000,
2015 Nov 06
4
Puzzled by eval
I am currently puzzled by a seach path behavior. I have a library of a dozen routines
getlabs(), getssn(), getecg(), ... that interface to local repositories and pull back
patient information. All have a the first 6 arguments in common, and immediately call a
second routine to do initial processing of these 6. The functions "joe" and "fred" below
capture the relevant
2011 Dec 07
2
plotting and coloring longitudinal data with three time points (ggplot2)
Dear list,
I have been struggling with this for some time now, and for the last hour I have been struggling to make a working example for the list. I hope someone out there have some experience with plotting longitudinal data that they will share.
My data is some patient data with three different time stamps. First the patients are identified at different times (first time stamp). Second, they
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 =
2009 Dec 09
1
reshape() makes R run out of memory (PR#14121)
Full_Name: Alexander L. Belikoff
Version: 2.8.1
OS: Ubuntu 9.04 (x86_64)
Submission from: (NULL) (67.244.71.200)
I'm trying to reshape the following data frame:
ID DATE1 DATE2 VALUE_TYPE VALUE
'abcd1233' 2009-11-12 2009-12-23 'TYPE1' 123.45
...
VALUE_TYPE is a string and is a factor with only 2 values
2012 May 12
1
Query regarding date as argument in functions - and about sqldf
Hi,
I have a query about sqldf, and dates in general. I couldnt find much on
the net or on the forums, hence I am here. Here is the issue:
I want to write a function that accepts 3 arguments: date1, date2 and a
dataframe, say 'df'. Within the function, I want to populate a temp
dataframe which essentially contains the output of the query "select * from
df where DATE between date1
2009 Dec 07
2
Filtering a zoo object based on index of another object
Hello everybody,
I have two datasets, observed and predicted.
Since my observed dataset is not in regular intervals, I need to filter my
predicted dataset based on the measurement date of my observed data.
Here, is an example similar to what I have
library(chron);library(zoo)
DATE<- seq(as.Date("2009-01-01"), as.Date("2009-05-01"), by = 1)
mydat<- rnorm(length(DATE),
2008 Jul 31
1
rollapply() to portions of a matrix
Hi everyone,
I have a rollapply statement that applies a function, in steps, over a data
matrix as follows:
#Code start
testm<-rollapply(mat, 100, by=100, min, na.rm=F)
#Code end
This moves down matrix 'mat' and calculates the minimum value over a 100 row
range, every 100 rows (i.e. no overlaps). NAs are not removed.
I want to modify this statement somehow so that the rollapply()
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 Apr 09
3
"fill in" values between rollapply
Hi,
Sorry ahead of time for not including data with this question.
Using rollapply to calculate mean values for 5 day blocks, I'd use this:
Roll5mean <- rollapply(data, 5, mean, by=5, align = c("left"))
My question is, can someone tell me how to fill in the days between each of
these means with the previously calculated mean? If this doesn't make
sense, I will clarify and
2013 Jun 27
3
using "rollapply" to calculate a moving sum or running sum?
#using "rollapply" to calculate a moving sum or running sum?
#I am tryign to use rollapply to calcualte a moving sum? #I tried
rollapply and get the error message
#"Error in seq.default(start.at, NROW(data), by = by) :
# wrong sign in 'by' argument"
#example:
mymatrix <- ( matrix(data=1:100, nrow=5, ncol=20) )
mymatrix_cumsum <- ( matrix(data=NA, nrow=5,
2013 Apr 13
2
Comparison of Date format
Hi,
?In the example you provided, it looks like the dates in Date2 happens first.? So, I changed it a bit.?
DataA<- read.table(text="
ID,Status,Date1,Date2 ??? ??? ??????
1,A,3-Feb-01,15-May-01 ??? ???
1,B,15-May-01,16-May-01 ??? ???
1,A,16-May-01,3-Sep-01 ??? ??? ??? ??? ???
1,B,3-Sep-01,13-Sep-01 ??? ??? ??? ??? ???
1,C,13-Sep-01,26-Feb-04 ??? ??? ??? ??? ???
2009 Jan 27
1
Mystery Error in midnightStandard
I wasn't even aware I was using midnightStandard. You won't find it in my
script.
Here is the relevant loop:
date1 = timeDate(charvec = Sys.Date(), format = "%Y-%m-%d")
date1
dow = 3;
for (i in 1:length(V4) ) {
x = read.csv(as.character(V4[[i]]), header = FALSE, na.strings="");
y = x[,1];
year = V2[[i]];
week = V3[[i]];
dtstr =
2011 Aug 07
1
all.equal doesn't work for POSIXlt objects
Hi all,
following sample code illustrates the problem :
Date1 <- Date2 <-
as.POSIXlt(seq.Date(as.Date("2010-04-01"),as.Date("2011-04-01"),by='day'))
identical(Date1,Date2)
all.equal(Date1,Date2)
identical() gives the correct answer. As there is no all.equal method
for POSIXlt objects, all.equal.list is used instead. Subsetting using
[[]] doesn't work
2011 Dec 02
2
Moving column averaging
# need zoo to use rollapply()
# your data (I called df)
df <- structure(list(a = 1:2, b = 2:3, c = c(5L, 9L), d = c(9L, 6L),
e = c(1L, 5L), f = c(4, 7)), .Names = c("a", "b", "c", "d",
"e", "f"), class = "data.frame", row.names = c(NA, -2L))
# transpose and make a zoo object
df2 <- zoo(t(df))
#rollapply to get