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