Displaying 10 results from an estimated 10 matches similar to: "For loop gets exponentially slower as dataset gets larger..."
2006 Jan 27
1
"Conditional" match?
I have two datasets, big and small.
s_date<-c(?2005-12-02?, ?2005-12-01?,
?2004-11-02?,?2002-10-05?,?2000-12-15?)
s_id<-c(?a?,?a?,?b?,?c?,?d?)
b_date<- c(?2005-12-31?, ?2005-12-31?,
?2004-12-31?,?2002-10-05?,?2001-10-31?,?1999-12-31?)
b_id<-c(?a?,?b?,?c?,?d?,?e?,?c?)
small<-data.frame(date_=as.Date(s_date),id=s_id)
big<-data.frame(date_=as.Date(b_date),id=b_id)
For each row
2010 Jun 09
3
Extracting Elements By Date
Dear R Gurus,
Thanks for any help in advance!
Date.frame: Returns.names
X id ticker date_ adjClose totret RankStk
258060 258060 13645T10 CP 2001-06-29 18.125 1877.758
My data frame is in the above format. I would like to filter by period, per
id (every 125 days) each consisting of 250 days, I.e. 1-250, 126-375, etc.
One important thing to note is that not all
2005 Oct 11
6
adding 1 month to a date
Within an R dataset, I have a date field called “date_”. (The dates are in the format “YYYY-MM-DD”, e.g. “1995-12-01”.)
How can I add or subtract “1 month” from this date, to get “1996-01-01” or “ “1995-11-01”.
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2010 Jun 07
3
Subsetting subsets of data.frames
Hey Everyone,
I have been stumped by this all day.
Basically, I have a data.frame of multiple columns. Of concern are "id" &
"date"
For some reason, oftentimes there are duplicates of data with the same date.
I would like to remove the duplicates per different id (removing duplicate
dates for the entire data.frame would leave nothing since different id's all
have
2012 Nov 28
2
data frame: adding columns from data and file title
Data processing?
I have a large number of csv files from animal tracks that look like this:
Date_ Time_ Speed
Course Type_ Distance
30/03/2012 11:15:05 108
121 -2
2006 Jan 13
0
Controller part of in-place editing
I''m doing some incremental improvements on scaffolding, and want to add
in-place editing to an admin section. I think I may have the view part
working right (at least, the editor pops up as expected) with this in my
view:
###
<% for link in @links %>
<tr>
<td> <div id="<%= ''url'' + link.id.to_s -%>"><%= link.url
2010 Jun 08
1
Filtering out a data.frame
Sample Data.Frame format
Name is Returns.nodup
X id ticker date_ adjClose totret RankStk
427225 427225 00174410 AHS 2001-11-13 21.66 100 1235
"id" uniquely defines a row
What I am trying to do is filter out id's that have less than 1500 data
points (by date)
First, I used
total<-by(Returns.nodup, Returns.nodup$id,nrow)
which subsetted by
2010 Jun 04
5
R Newbie, please help!
Hello Everyone,
I just started a new job & it requires heavy use of R to analyze datasets.
I have a data.table that looks like this. It is sorted by ID & Date, there
are about 150 different IDs & the dataset spans 3 million rows. The main
columns of concern are ID, date, and totret. What I need to do is to derive
daily returns for each ID from totret, which is simply totret at time
2007 May 03
1
reshape question
Hello all,
A quick question concerning a behavior of reshape I fail tu understand, probably something obvious but I just can't see it.
With the following data frame further referred to as tab :
2005 Apr 21
10
apci issue
Hi,
Updated to current bk today, and my machine stopped booting ...
I''ve tracked it down to the apic changes from end of last week.
cset 1.1307 boots fine, 1.1308 doesn''t.
Diff of the boot messages is below. Full logs are also attached.
Gerd
--- log-1.1307 2005-04-21 14:40:57.372885027 +0200
+++ log-1.1308 2005-04-21 14:38:52.236553392 +0200
@@ -7,7 +7,7 @@