similar to: unique, but keep LAST occurence

Displaying 20 results from an estimated 3000 matches similar to: "unique, but keep LAST occurence"

2005 Nov 16
1
COM dates (was origin and "origin<-" in chron)
I was just looking for an easy way to convert between COM datetime and chron datetime (both ways.) I found examples on the list, but they involved origin. Does anyone have functions for converting COM datetime <-> chron datetimethat work "safely"? David L. Reiner > -----Original Message----- > From: Gabor Grothendieck [mailto:ggrothendieck@gmail.com] >
2005 May 06
4
Choices from a matrix
Could someone please suggest a more clever solution to the following problem than my loop below? Given X a 2xN matrix X, and I a k-subset of N, Generate the (2^k)xN matrix Y with columns not in I all zero and the other columns with all choices of an entry from the first or second row of X. For example, with X <- matrix(1:8, nrow=2) I <- c(1,3) X is 1 3 5 7 2 4 6 8 and Y should be 1 0 5
2004 Sep 13
2
Can I find the datetime an object was last assigned to/saved?
I'm using v 1.9.1 under Windoz XP. Can I do the equivalent of "ls -l" on my R objects? R's "ls()" lists only the names. Thanks! David L. Reiner Rho Trading 440 S. LaSalle St -- Suite 620 Chicago IL 60605 312-362-4963 (voice) 312-362-4941 (fax) [[alternative HTML version deleted]]
2005 Nov 15
1
origin and "origin<-" functions on chron
I'm trying to use/modify some code I found (at Omegahat, but I've seem similar usage elsewhere.) It contains the lines: if(any(origin(chronDate)!=orig)) origin(chronDate) <- orig Let's say: > require("chron") [1] TRUE > chronDate <- chron("11/15/2005", format="m/d/y", origin.=c(12,31,1899)) > orig <- c(month=12, day=31,
2006 Jun 15
2
Standard Deviation Distribution
I'm having trouble with the standard deviation distribution as shown on http://mathworld.wolfram.com/StandardDeviationDistribution.html . (Eric Weisstein references Kenney and Keeping 1951, which I can't check.) I believe the graphs they show, but when I code the function in R, according to the listed formula, I get very different graphs. Would someone please point out my error or tell
2004 Sep 29
2
How to print landscape from script in Windows: dev.print(win.print, printer="local printer name", ...) does not accept horizontal=TRUE
This is a windows-specific question. After generating a plot, I can print from scripts or the command line with > dev.print(win.print,printer="local windows printer name") I would like to print in landscape mode. From the menus, I can accomplish this by changing the properties of the printer before clicking "print". However, I tried adding
2005 Apr 21
1
R 2.1.0 for Windows installation error? atanh not in R.dll?
Could someone please tell me what I did wrong to create this message or what I should do to correct this problem? I downloaded 2.1.0 Windows binary and installed into C:/R/rw2010, using the installer. I ran md5check.exe in C:/R/rw2010/bin/ and got "No errors." The problem is this: When I start up Rgui.exe from its shortcut (target= C:\R\rw2010\bin\Rgui.exe --save -sdi, Start in
2005 Apr 28
1
standard errors for orthogonal linear regression
Could someone please help me by giving me a reference to how one computes standard errors for the coefficients in an orthogonal linear regression, or perhaps someone has some R code? (I would accept a derivation or formula, but as a former teacher, I know how that can rankle.) I tried to imitate what's done in the code for lm() but went astray somewhere and got nonsense. (This type of
2005 Jul 06
1
pretty for date-time?
pretty() works well for numbers and axTicks() can help for potting log axes, but has anyone written a pretty for chron objects (or other date or date-time classes)? It would have natural units of years, months, .., days, hours, (minutes?), and it would choose the appropriate unit based on the date(time) range. I have searched the archives and documentation to no avail. (I wrote one of these back
2004 Nov 08
1
can one evaluate an expression in a comment? (or insert results into history?)
I'd like to insert (for example) the current datetime into a comment so it goes into the history. I can of course cut and paste the results of date() into a comment line, but it would be easier and more powerful to be able to type something like > hstamp() and have it go into the history. More generally, I would like to put any expression to be evaluated into this function. For
2004 Oct 01
3
Can grid lines color in a plot be specified?
R-help Is there any way to specify the color of grid lines in a simple plot? par(color.tick.marks=c("grey")) plot(rnorm(10),tck=1) Thank you
2004 Nov 08
1
can one evaluate an expression in a comment? (or insert resultsinto history?)
But that doesn't put the result into the history buffer, to be written to a file only later when I savehistory(filename). Bert Gunter also suggested ?capture.output and ?textConnection, but I cannot see how to get text into the history buffer as comments, but with evaluated expressions (values). I know how to use paste, sink, write, etc. but nothing that I can see inserts into the history
2005 Jun 29
6
x*x*x*... vs x^n
Hi I have been wondering if there one can speed up calculating small powers of numbers such as x^8 using multiplication. In addition, one can be a bit clever and calculate x^8 using only 3 multiplies. look at this: > f1 <- function(x){x*x*x*x*x*x*x*x} > f2 <- function(x){x^8} > f3 <- function(x){x2 <- x*x;x4 <- x2*x2;return(x4*x4)} [so f1() and f2() and f3() are
2005 Jun 29
3
moving correlation coef ?
Hello, R gives us the correlation functions cor(). (Many thanks ;-)) Does it also exist a "moving correlation" coefficient ? (like the moving average). If not, could someone give me some infos or link on how to practically implement such a function in R. (I did search for "moving correlation" on the R homepage but didn't find anything.) Thank you. Vincent
2009 Aug 03
3
Help with reshaping data.frame
I'm having trouble reshaping a data.frame from long to wide. (I think that's the right terminology; feel free to educate me.) I've looked at the reshape function and package and plyr package, but I can't quite figure out how to do this after a dozen variations. I have a data.frame with more levels than this, but similar to: > tst K1 K2 K3 V1 V2 V3 1 10 D a 0.08 99
2008 Mar 11
1
plot.zoo warnings - ignore or look for problem?
I'm getting warnings when I plot a zoo object: > dts <- chron(rep("2007-09-10", 5), paste("00:0", 0:4, ":00", sep=""), c("y-m-d", "h:m:s")) > dat.zoo <- zoo(1:5, dts) > plot(dat.zoo) Warning messages: 1: In v[[perm[1]]] : partial match of 'm' to 'month' 2: In v[[perm[2]]] : partial match of 'd'
2009 Jan 23
1
list.files changed in 2.7.0
I just noticed a change in the behavior of list.files from 2.6.1pat to 2.7.0 (I noticed it in 2.8.1 and traced back.) Previously, if the directory ended with a slash, and full.names=TRUE, the names returned had a single slash at the end of the directory, but now there are two. I noticed since I was getting a list of certain files and then grepping in the list for a full name formed with a
2007 Aug 01
1
New R package sqldf
sqldf is an R package for running SQL select statements on one or more R data frames. It is optimized for convenience making it useful for ad hoc queries against R data frames. Given an SQL select statement whose tables are the names of R data frames it: - sets up the database (by default it transparently sets up an in memory SQLite database using RSQLite; however, MySQL via RMySQL, can be
2007 Aug 01
1
New R package sqldf
sqldf is an R package for running SQL select statements on one or more R data frames. It is optimized for convenience making it useful for ad hoc queries against R data frames. Given an SQL select statement whose tables are the names of R data frames it: - sets up the database (by default it transparently sets up an in memory SQLite database using RSQLite; however, MySQL via RMySQL, can be
2008 Sep 05
1
casting help please
I have a data.frame which I believe is melted already and am having trouble casting it to 'wide' format. It looks something like > (x <- data.frame(ticker=c(rep("A",5),rep("B",6)), date=c(1:5, 1:6), value=c(NA,100*exp(rnorm(10,0,.1))))) > cast(x, date ~ ticker) # this does what I want with toy data But when I use my real data frame >