Displaying 20 results from an estimated 10000 matches similar to: "Extracting year from a date object"
2011 Mar 01
2
Does POSIXlt extract date components properly?
I would like to use POSIX classes to store dates and extract components of
dates. Following the example in Spector ("Data Manipulation in R"), I
create a date
> mydate = as. POSIXlt('2005-4-19 7:01:00')
I then successfully extract the day with the command
> mydate$day
[1] 19
But when I try to extract the month
> mydate$mon
[1] 3
it returns the wrong month. And
2008 Sep 17
3
Dates in C api
r-devel,
I've been trying to write a C plugin for R, and I'm struggling to
understand how dates are represented.
I can create a date in R:
> mydate<-as.Date(1, origin="1900-01-01") mydate
[1] "1900-01-02"
When I pass my date to a plugin, though, it's type is that of a real.
There doesn't seem to be a date type in Rinternals.h, is there a way to
2007 Jun 13
5
Confusion with sapply
Hi,
I have some confusion in applying a function over a column.
Here's my function. I just need to shift non-March month-ends to March
month-ends. Initially I tried seq.dates, but one cannot give a negative
increment (decrement) here.
return(as.Date(seq.dates(format(xdate,"%m/%d/%Y"),by="months",len=4)[4])
)
Hence this simple function:
> mydate <-
2009 Aug 28
2
new data.frame summed by date
Hi,
I wonder if someone can suggest how to create a new data.frame Y
from X where X$PL_Pos is summed by each unique X$MyDate. Y should end
up with two (or more) columns Y$MyDate and Y$PL_Sum with its value
being the cumsum of all the values in X for that date. - a 'daily
cumsum'.
Thanks,
Mark
TStoDate = function (TSDate) {
X = strptime(TSDate + 19e6L, "%Y%m%d")
2011 May 19
1
Creating a "shifted" month (one that starts not on the first of each month but on another date)
Hello!
I have a data frame with dates. I need to create a new "month" that
starts on the 20th of each month - because I'll need to aggregate my
data later by that "shifted" month.
I wrote the code below and it works. However, I was wondering if there
is some ready-made function in some package - that makes it
easier/more elegant?
Thanks a lot!
# Example data:
2009 Jan 21
1
finding row and column indices of date in multiple columns of a data frame
Hi,
I have a data.frame SAMPLES with columns:
Site Site# Season Day1 Day2 Day3
Day1, Day2, Day3 are class "Date", the other columns are numeric or
factor.
I have a date "mydate" that may or may not be listed in my data.frame
and I need to find that out.
If "mydate" is there, I want to get the number of the data.frame row
where it occurs.
2009 Mar 11
1
Is this a documentation bug? Spss dates import
Hello R-user
bug seekers are needed!
In order to perform these simple tasks you have to use a copy of SPSS
and obviously R.
The problem is that date conversion of data coming from SPSS
gives wrong results, if we follow ?as.POSIXct
## SPSS dates (R-help 2006-02-17)
z <- c(10485849600, 10477641600, 10561104000, 10562745600)
as.Date(as.POSIXct(z, origin="1582-10-14",
2008 Jun 17
4
Formating Date Field
First.jsp
------------------
<jsp:usebean id="db" class="db.dbClass" scope=session/>
<html>
<body>
<form action="MyAction.jsp" method="post">
<% ResultSet rs=db.executeQuery("select no,name from mytable");
while(rs.next())
{%>
<input type=checkbox value=<%=rs.getString(1)%> onclick=callJs(<
2011 Jul 14
2
cbind in aggregate formula - based on an existing object (vector)
Hello!
I am aggregating using a formula in aggregate - of the type:
aggregate(cbind(var1,var2,var3)~factor1+factor2,sum,data=mydata)
However, I actually have an object (vector of my variables to be aggregated):
myvars<-c("var1","var2","var3")
I'd like my aggregate formula (its "cbind" part) to be able to use my
"myvars" object. Is it
2006 May 21
1
POSIX, time zone and Windows
Dear Listers,
Apologize to pile up on the 'tz' issue in POSIX objects. I have a
'simple' thing on which I must make up my mind but cannot do it from the
existing R-help threads. I am currently working on dog telemetry in
China, and download time information from GPS collars. I would like to
set up the corresponding POSIXxx variables in R to a given time zone. Eg
Pekin
2009 Oct 27
2
Year and Month extraction from Date object.
Hello,
I have seen much discussion on Date. But I can't seem to do this simple operation. I can convert a string to a date:
d <- as.Date(DATE, format="%m/%d/%Y")
But what I want to do is extract the year and month so I can construct an element in a ts object. Ideally I would like to see d$year but that doesn't seem to be available. Once I have a Date object how can I get an
2011 Apr 18
1
using "aggregate" when variable names contain spaces
Hello!
my data set has many variables. Unfortuantely, many of those variables
contain spaces in their names.
I need advice on: how to refer to variable names in the formula for
"aggregate". See example below:
### Generating example data set:
mydate = rep(seq(as.Date("2008-12-01"), length = 3, by = "month"),4)
value1=c(1,10,100,2,20,200,3,30,300,4,40,400)
2011 Apr 04
2
merging 2 frames while keeping all the entries from the "reference" frame
Hello!
I have my data frame "mydata" (below) and data frame "reference" -
that contains all the dates I would like to be present in the final
data frame.
I am trying to merge them so that the the result data frame contains
all 8 dates in both subgroups (i.e., Group1 should have 8 rows and
Group2 too). But when I merge it it's not coming out this way. Any
hint would be
2013 Apr 02
2
Create a vector without using an external 'if statement'
Dear R-users,
suppose I have three dataframes like these
df1:
mydate min_temp
31032013 12
01042013 8
02042013 -999
df2:
mydate min_temp
31032013 10
01042013 11
02042013 14
df3:
mydate min_temp
31032013 4
01042013 3
02042013 5
where -999 means that the temperature data is not available (at the moment I cannot change it to NA because I am not the db administrator);
suppose also that oggi is
2011 Oct 27
1
plotting large time series
hello,
I got a problem with plotting large time series, since I want to store
the results in a .PDF file (I want to store several pages of plots). The
PDF files get too large to be handled (> 10MB, one was even 200MB big).
So I wonder, if there would be a possibilty to either
- reduce the file size of the PDF
- change the way the plot is generated to reduce the plot size?
I use:
2007 Dec 23
11
return day from date (javascript) ?
Ok, I know this isn''t a Rails problem, but if you could help me out
that''d be brill.
I''ve used JavaScript to create a new Date object containing a date of my
choice...
mydate = new Date("11/24/2007");
//going with Javascript''s mm/dd/yyyy format
now this is good, what i want to do now is put in an integer variable
the number for the day, in this case
2020 Mar 10
2
Fwd: Windows upssched does not work
Hi,
I have problem with upssched on windows. Upssched is not executed. I
have 2 scripts, 1 for notification in upsmon and second for scheduling
in upssched. Monitoring is working fine, script write to log. I'm
using binary windows installer 2.6.5-6 from NUT.
Here are my configs:
--- nut.conf
MODE=netclient
--- upsmon.conf
MONITOR ups_1000 at 192.168.3.95 1 <user> <password> slave
2018 Jun 09
4
Date class shows Inf as NA; this confuses the use of is.na()
And now I've seen I copied the wrong part of ?is.na
> The default method for is.na applied to an atomic vector returns a
logical vector of the same length as its argument x, containing TRUE for
those elements marked NA or, for numeric or complex vectors, NaN, and FALSE
otherwise.
Key point being "atomic vector" here.
On Sat, Jun 9, 2018 at 1:41 PM, Joris Meys <jorismeys at
2018 Jun 08
2
Date class shows Inf as NA; this confuses the use of is.na()
Indeed. as_date is from lubridate, but the same holds for as.Date.
The output and it's interpretation should be consistent, otherwise it leads
to confusion when programming. I understand that the difference exists
after asking a question on Stack Overflow:
https://stackoverflow.com/q/50766089/914686
This understanding is never mentioned in the documentation - that an Inf
date is actually
2011 Aug 24
2
data manipulation and summaries with few million rows
I have a data set with about 6 million rows and 50 columns. It is a
mixture of dates, factors, and numerics.
What I am trying to accomplish can be seen with the following
simplified data, which is given as dput output below.
> head(myData)
mydate gender mygroup id
1 2012-03-25 F A 1
2 2005-05-23 F B 2
3 2005-09-08 F B 2
4 2005-12-07 F B 2