similar to: Interaction between aggregate() and length()

Displaying 20 results from an estimated 10000 matches similar to: "Interaction between aggregate() and length()"

2009 Feb 10
1
aggregate taking way too long to count.
Folks, I'm checking the structure of a dataframe for duplicate parameters at a site station (i.e depth should be measured once, not twice), using aggregate to count each parameter within a site station. The fake data below has only 26000 rows, and takes roughly 14 seconds. My real data has 750000 rows and I had to stop execution after about an hour. The by() function is faster, but I
2012 Jan 19
2
POSIXct value display incorrect for some values
First, the reproducable example, showing how converting from character to POSIXct to character changes the milliseconds in the first time stamp though not in the second: > as.POSIXct('2010-06-03 9:03:58.324') [1] "2010-06-03 09:03:58.323 PDT" > as.POSIXct('2010-06-03 9:03:58.325') [1] "2010-06-03 09:03:58.325 PDT" This seems to be due to truncation of
2009 Apr 02
1
Updating a data frame
Folks, Updating values in a table is simple in SAS or SQL, but I've wracked my brain looking for an elegant solution in R to no avail thus far. Certainly this is a common need that's been solved in dozens of different ways. Given an initial dataframe nn and a smaller dataframe of updates uu, I'd like to replace the values in nn <- expand.grid('a'=1:4, 'b'=1:3)
2005 Oct 07
2
Assign references
Folks, I've run into trouble while writing functions that I hope will create and modify a dataframe or two. To that end I've written a toy function that simply sets a couple of variables (well, tries but fails). Searching the archives, Thomas Lumley recently explained the <<- operator, showing that it was necessary for x and y to exist prior to the function call, but I haven't
2005 Jul 12
4
Calculation of group summaries
I know R has a steep learning curve, but from where I stand the slope looks like a sheer cliff. I'm pawing through the available docs and have come across examples which come close to what I want but are proving difficult for me to modify for my use. Calculating simple group means is fairly straight forward: data(PlantGrowth) attach(PlantGrowth) stack(mean(unstack(PlantGrowth)))
2009 Jul 10
1
RUnit detects parse error, but why?
Folks, An RUnit test suite is failing after all tests are complete with the following message: Error in parse(n = -1, file = file) : unexpected '}' at 620: 621: } All individual tests work when run individually, and all but one run within the RUnit test suite. What might be causing this? A similar error message during package creation was discussed earlier
2009 Jul 02
1
Package 'operators'
Folks, In brief -- how many of you have found the 'operators' package to be valuable in their work? Not that I lack respect for the amount of work involved in creating and maintaining a package, but I am unsure about the utility of these new operators. Several of the operators appear to offer different ways of accomplishing tasks that are already relatively easy in base R -- regular
2012 Sep 27
1
Is there a way to source from a specific Git repository without hardcoding the location everywhere?
Folks, A small group of us are working together to develop a set of R functions to support data management and analysis using Eclipse/StatET in a Windows environment. We are using Git/EGit for version control. We work within our own repository and occasionally push to a common remote location. I'd like to have the code source files from the 'local' git repository without
2010 Sep 01
2
invert order
Dear R-help list users, I have a huge vector of numbers, how I can invert orden? For example x <- 1:10000000 I would like to obtain x_r <- 10000000:1 Thanks, Sebastian.
2010 Dec 09
1
how to use diff() with different variables?
Hi, I first should say I am new to R. I have searched without success the R-archives to see if I could find an answer to what I am about to ask you. My dataset is like: x fine 1 A 2010-12-09 07:57:33 2 B 2010-12-09 08:05:00 3 C 2010-12-08 20:42:00 ... that is: 'data.frame': 3 obs. of 2 variables: $ x : Factor w/ 3 levels "A","B","C":
2011 Jul 13
3
Colors in R
HI everyone, I''m trying to assign colors to multiple lines in a graph. Problem is I don''t want to type in as many colors as there are lines....is there a way around this? In brief, I''m plotting the logratio for up to 60 samples and want a different color for each sample. Here is the code I''m using now.. Any help is greatly appreciated.. Best LT data <-
2009 Apr 22
2
R-User groups in North America (SF, LA, NYC, Ottawa)
Hi R folks, I'd like to announce several new R users groups here in SF, LA, NYC, and Ottawa - as well as their next scheduled event. The goal of these user groups, besides gently explaining 'drop=TRUE' to the uninitiated, is to exchange knowledge, promote best practices, and spur the adoption of R for innovative applications. If I've missed any groups here, please feel to add on
2008 Dec 11
3
Logical "in" test
OK, this should be trivial but I'm not finding it. I want to compress the test, if (i==7 | i==10 | i==30 | i==50) {} into something like if (i in c(7,10,30,50)) {} so I can build a "excludes" vector excludes <- c(7,10,30,50) and test if (i in excludes) {} However, I'm not finding a clue on how to accomplish this, if it can be done. Would someone with more R
2009 Feb 04
3
R command to compare two vectors?
By any chance is there an R command to compare two vectors?   For example, a_tmp<-c("a", "b", "c", "d", "e", "f", "g", 'h') b_tmp<-c("a", "c", "e", "g")   I would like to compare b_tmp against a_tmp to determine if the members of b_tmp are part of a_tmp.    I tried
2011 Apr 11
4
nndist R vs. ArcGIS
Can anyone tell me why I would get different average nearest neighbor values for the same set of coordinates between ArcGIS 10 and R? Sometimes the difference in distance is over 1.3 km. Alexis -- View this message in context: http://r.789695.n4.nabble.com/nndist-R-vs-ArcGIS-tp3442375p3442375.html Sent from the R help mailing list archive at Nabble.com.
2010 Dec 10
3
Delete observations with a frequency < x
Hi, I have two columns with data (both identifiers - it's an affiliation list) and I would like to delete the rows in which the observations in the second column have a frequency < 5 in the entire second column. Example: 1 a 1 b 1 c 2 a 2 b 2 d Let's say, I would like to delete the rows in which the observation in the second column has a frequency < 2 in
2011 Feb 25
6
preventing repeat in "paste"
Hello! s<-"start"; e<-"end" middle<-as.character(c(1,2,3)) I would like to get the following result: "start 123 end" or "start 1 2 3 end" or "start 1,2,3 end" How can I avoide this (undesired) result: paste(s,middle,e,sep=" ") Thank you! -- Dimitri Liakhovitski Ninah Consulting www.ninah.com
2011 Apr 19
3
How to program with colleagues
Dear all, my colleagues and I have to write some R code for some of our projects. I would like to ask you help to organize us a little. a. Do you know if there is any system that can convert our R scripts to html pages with some nice dependency graphs (which functions calls which). b. Could you please suggest me an easy way to exchange the R code with my colleagues. I know about these version
2010 Nov 05
4
subsets, %in%
Hi, I have a question about %in% and subsettin data frames. Say I need to keep ID 1,2,4,5, 10 from the data frame dat. I can do: dat <- data.frame(ID = 1:10, var = 1:10) someID <- c(1,2,4,5,10) subset(dat, dat$ID %in% someID) Is there a quick way to do the opposite, ie to do a subset that contains all ID but someID? Something like %not in%, which would *remove* lines with ID in
2012 Jan 27
2
PosixCT subsecond accuracy
A sample of the data I have is: > head(sensor) logged_on accx accy accz compassx compassy compassz gyrox gyroy gyroz 1 1326561428000 -0.4602 0.8346 0.0936 0.145508 -0.350586 0.259766 59.617390 28.521740 59.617390 2 1326561428050 -0.4212 1.0452 0.1326 0.219727 -0.321289 0.241211 88.695656 27.478260 88.695656 3 1326561428100 -0.2496 1.3416 0.2886 0.214844 -0.326172