similar to: replacing elements in matrix: fastest method?

Displaying 20 results from an estimated 8000 matches similar to: "replacing elements in matrix: fastest method?"

2003 Oct 15
2
Subseting in a 3D array
Hi! I have a 3d array: > dim(ib5km15.dbc) [1] 190 241 19 and a set of positions to extract: > ib5km.lincol.random[1:3,] [,1] [,2] [1,] 78 70 [2,] 29 213 [3,] 180 22 Geting the values of a 2D array for that set of positions would be: > ima <- ib5km15.dbc[,,1] > ima[ib5km.lincol.random[1:10,]] but don't find the way for the case of the 3D array: >
2003 Feb 17
4
inserting elements in a list
I've searched the doc for insert and could not find the way to do the following, hope someone can help: Let's say we have a vector: > a [1] "1" "2" "3" "5" "6" "3" and we want to insert a "7" after any given "3", i.e., we want vector a to become: [1] "1" "2" "3"
2001 Aug 30
1
imagenrgb: Function to display RGB images in R
I've writen this function (imagenrgb) to display a (m,n,3) array as a RGB image with ngris^3 colors and,optionally, stretching. If option ver=F, it does not display but saves a pseudocolor version of the image as a list (so that subsequent displays are faster). I'd appreciate feedback and improvements and hope that it's useful for others. Example of use: > dim(imatest) [1] 100
2009 Mar 21
0
Solved: [Fwd: Matching failure in merge()]
I've found where the problem was and a way to solve this problem: One dataset was encoded (and read) as UTF-8 and the other one was encoded (en read) as latin3 In this case, even if at the terminal you see the same characters, R states that the two elements are not equal. Don't know if this is the way it has to be, or this is a bug. Anyway, editing the second file (encoded as latin3)
2008 Sep 12
2
Greyed text in the background of a plot
Hi! Is there any way of having a greyed ("ghosted") text (i.e, 2006) in the background of a plot? I'm making a dynamic plot and would like to show the year of each time step as a big greyed text in the background. (the idea comes from Hans Rosling video: http://video.google.com/videoplay?docid=4237353244338529080&sourceid=searchfeed ) Thanks Agus -- Dr. Agustin Lobo Institut
2008 May 19
2
Log or diary file
Hi! Is it possible to set a file to which both commands and output would get automatically saved? I've tried with sink(), but only get the output. I mean something like a combined history and sink, as you get with File/Save to File.. in the windows GUI. Tis is done with diary filename in Matlab, and you can state diary on and diary off to control what is being saved to the file. Thanks Agus
2009 Jul 03
4
Function to eliminate blank space within strings?
Is there an specific function to eliminate blank space within strings? Thanks -- Dr. Agustin Lobo Institut de Ciencies de la Terra "Jaume Almera" (CSIC) LLuis Sole Sabaris s/n 08028 Barcelona Spain Tel. 34 934095410 Fax. 34 934110012 email: Agustin.Lobo at ija.csic.es http://www.ija.csic.es/gt/obster
2007 Jul 24
1
Renamig a factor
Which is the proper way to rename a factor? If I do: test$Parc[test$Parc=="Ol?rdola"]<-"Ol?rdola" R complains that Warning message: invalid factor level, NAs generated in: `[<-.factor`(`*tmp*`, test$Parc == "Ol?rdola", value = "Ol?rdola") Thanks Agus -- Dr. Agustin Lobo Institut de Ciencies de la Terra "Jaume Almera" (CSIC) LLuis Sole
2008 Apr 18
1
space between plots
I've set layout(matrix(c(1,3,2,4),ncol=2)) and par(mar=c(0, 4, 4, 0) + 0.0) and par(mar=c(0, 0, 4, 3) + 0.0) for the upper-left and upper-right plots, but still get an space between both plots, is there any way to completely eliminate that space? Thanks Agus -- Dr. Agustin Lobo Institut de Ciencies de la Terra "Jaume Almera" (CSIC) LLuis Sole Sabaris s/n 08028 Barcelona Spain
2008 Jun 27
4
Recoding
Hi! Given a vector (or a factor within a df),i.e. v1 <- c(1,1,1,2,3,4,1,10,3) and a dictionary cbind(c(1,2,3),c(1001,1002,1003)) is there a function (on the same line than recode() in car) to get v2 as c(1001,1001,1001,1002,1003,4,1001,10,1003) ? I'm using myself a function based on match() since long ago (I think that thanks to advice by Prof. B. Ripley), but would like to know if there
2008 May 21
2
Proportional axes
Hi! If I'm plotting 2 variables with the same units (i.e. wing length of 2 species), how can I force that X and Y axes have the same size for length unit? For example, if X ranges from 0 to 10 and Y ranges from 10 to 30, I want Y axis to be twice as long as X axis. I know I can just put xlim and ylim from 0 to 30, i.e., plot(runif(10,0,10),runif(10,10,30),xlim=c(0,30),ylim=c(0,30)) but this
2009 Sep 02
1
Problem at subsetting matrix by using dimnames
Given: > mitest <- matrix(1:16,ncol=4) > dimnames(mitest)[[1]] <- c("a","b","c","d") > dimnames(mitest)[[2]] <- c("a","b","c","d") > mitest a b c d a 1 5 9 13 b 2 6 10 14 c 3 7 11 15 d 4 8 12 16 I can do: > mitest[cbind(c(1,2,3),c(2,3,2))] [1] 5 10 7 but using the names does not
2008 Jul 28
1
Converting from char to POSIX:
Given char vector delme2: > str(delme2) chr [1:1065] "30-1-08 8:48:21" "30-1-08 8:55:17" "30-1-08 9:00:22" ... I do: > delme3 <- strptime(delme2,format="%d-%m-%y %H:%M:%S") But then: > str(delme3) POSIXlt[1:9], format: "2008-01-30 08:48:21" "2008-01-30 08:55:17" ... > length(delme3) [1] 9 whie >
2012 May 28
2
zoo: variable gets modified at making zoo object
I'm doing: > alyL32007z <- zoo(alyL32007,alyL32007$time) > range(time(alyL32007z)) [1] "2007-01-01 00:00:00 UTC" "2007-12-31 23:30:00 UTC" But then, while the original variable is: > summary(alyL32007$NEE_st) Min. 1st Qu. Median Mean 3rd Qu. Max. NA's -15.340 -1.615 -0.054 -0.814 0.750 8.965 11124 the variable within the zoo object
2011 Sep 16
1
cutree() and rect.hclust(): different labelling of classes
I've found that while cutree() and rect.hclust() make the same classes for a given height in the dendrogram, the actual labeling of the classes is different. For example, both produce the same 4 classes but class 1 according to cutree() is class 4 according to rect.hclust(). Would it be possible that future versions provide the same labeling? rect.hclust() is useful to display the classes
2011 Aug 24
1
as.numeric() and POSIXct format
Hi! I'm confused by this: > as.numeric(as.POSIXct(518400,origin="2001-01-01")) [1] 978822000 I guess the problem is that as.numeric() assumes a different origin, but cannot find any default origin. How can I get back the seconds from the POSIXct format? In other words, which the inverse function of as.POSIXct()? I've tried as.numeric and unclass() using a origin=
2013 Feb 28
1
query labels in iplot() (or other interactive scatterplot)
By Ctr-moving the cursor over a point in an iplot() scatterplot (package iplots) it is possible to check the exact x,y coordinates of a given point. Is it possible to check a text label for that point as well? (i.e., the same info that would get printed on the graphic using text(x,y, labels=v) or with identify(x,y,labels), but I do not want to get the labels permanently plotted on the graphic)
2012 Jun 08
3
day of the year for chron objects
Hi! Is not there an standard R function to retrieve the day of the year (since 1st Jan of the same year)? I know I can make my own using julian, but find it weird that having days(), months() etc doy() does not exist as an standard function. Also, is the following not a bit inconsistent? > a <- chron("20100506",format="ymd") > a [1] 100506 > years(a) [1] 2010
2008 Dec 04
0
reading files (readOGR) and non-ascii characters
I'm forwarding to this list as I've got no answer in [R-sig-Geo] and perhaps this issue is not exclusive of readOGR() I'm using ubuntu 8.04 andR version 2.8.0 (2008-10-20) -------- Original Message -------- Subject: readOGR and non-ascii characters Date: Wed, 03 Dec 2008 14:22:34 +0100 From: Agustin Lobo <aloboaleu at gmail.com> Reply-To: Agustin.Lobo at ija.csic.es To:
2009 May 12
0
[Fwd: Re: Problem at instaling robustbase (Rlapack) (2)]
Martin, Although I did remove the ln libRlapack.so -> ./lapack.so and sudo apt-get install r-cran-robustbase went fine (as does if the installation is done through Synaptic), once I start R I get: > require(robustbase) Loading required package: robustbase Error in dyn.load(file, DLLpath = DLLpath, ...) : unable to load shared library