Displaying 20 results from an estimated 3000 matches similar to: "par(mfrow,mai) and multiple plot problem"
2005 Jun 13
3
extracting components of a list
Hi
how do I extract those components of a list that satisfy a certain
requirement? If
jj <- list(list(a=1,b=4:7),list(a=5,b=3:6),list(a=10,b=4:5))
I want just the components of jj that have b[1] ==4 which in this case
would be the first and
third of jj, viz list (jj[[1]],jj[[3]]).
How to do this efficiently?
My only idea was to loop through jj, and set unwanted components to
NULL,
2005 Sep 21
3
size of subplots with par() / layout()
Hi
If I do this:
par(mfrow=c(2,2))
persp(matrix(1:4,6,6),box=F,phi=33,theta=33)
persp(matrix(1:4,6,6),box=F,phi=33,theta=33)
persp(matrix(1:4,6,6),box=F,phi=33,theta=33)
persp(matrix(1:4,6,6),box=F,phi=33,theta=33)
(
or indeed
layout(matrix(1:4,2,2))
persp . . . .
)
then the mesh plots look too small to me. How do I make them larger?
--
Robin Hankin
Uncertainty Analyst
National
2007 Apr 17
1
no visible binding for global variable
Hello everyone
I am trying to get one of my packages through R's QC.
The package is clean for me under R-2.4.1, R-2.5.0, and
R-devel, but Kurt gets
>
> * checking R code for possible problems ... WARNING
> hypercube: no visible binding for global variable ?f?
Function hypercube() [cut-&-pasted below] is intended to
return an adjacency matrix for an n-dimensional
2007 Jun 27
1
inherits() and virtual classes
Hi
How do I test for an object having a particular virtual class?
In the following, "onion" is a virtual class, and "octonion" is
a non-virtual class contained in onion. The last call
to inherits() gives FALSE [R-2.5.0], when inherits.Rd led
me to expect TRUE.
setClass("onion",
representation = "VIRTUAL"
)
2004 Sep 08
3
do.call("[", ...) question
Hi again everyone
I have an arbitrarily dimensional array "a" and a list "jj" of length
length(dim(a)). The elements of jj are vectors of indexes.
How do I use do.call() to extract a[ jj[[1]], jj[[2]], jj[[3]], ...] ?
Toy example follows:
a <- matrix(1:30,5,6)
jj <- list(5:1,6:1)
I want the following
a[ jj[[1]],jj[[2]] ]
How do I do this?
OBAttempts:
2005 Feb 07
4
proportional matrix rows
Hi
I have a two-column integer matrix like this:
R> jj
[,1] [,2]
[1,] -1 1
[2,] -2 2
[3,] -7 6
[4,] -8 7
[5,] -6 5
[6,] -9 8
[7,] -5 4
[8,] 3 -3
[9,] -10 9
[10,] -4 3
I want a diagnostic that detects whether a row is a multiple of
the first row or not. In this case, this would be rows 1,2, and 8.
How to do this
2006 Oct 31
1
setReplaceMethod
Hi
If x <- 1:10 then x[5] <- 1i will promote
x to be a complex vector.
Suppose I have an S4 class "brob", and have functions
is.brob(), as.brob(), as.numeric() and so forth (minimal self-contained
code below).
If x is numeric (1:10, say) and y is a brob, what
is the best way to make
x[5] <- y
promote x to a brob in the same way as the complex example?
Or is
2008 Apr 02
1
"[<-" plus drop-type extra argument
Hello
I am writing a replacement method for an S4 class and want to pass
an additional argument to "[<-"() along the lines of "["()'s "drop"
argument.
Specifically, I have an S4 class, call it "foo", with a slot 'x'
that is a
vector and a slot 'NC' that is a scalar.
I want to be able to pass a Boolean argument to the
2004 Jan 14
1
arrows on contour lines
Hello everybody
I'm using contour() to draw streamlines of potential flow, eg
jj <- seq(from= -4, to=4,len=20)
jj <- outer(jj,jj,function(x,y){x})+1i*outer(jj,jj,function(x,y){y})
f <- function(x){x^2}
contour(Im(f(jj)), nlevels=44 , labels="")
How best to put arrows on the contour lines to show the direction of flow?
(ie I want contour lines looking like
2005 Jan 07
1
Visualizing complex analytic functions using domain coloring
Hi
has anyone coded up domain colouring for visualizing complex analytic
functions
(such as elliptic functions)?
[
the idea is to depict a complex function f(z) using a filled.contour()
variant
in which the hue is given by Arg(f(z)), and the saturation by Mod(f(z)).
]
--
Robin Hankin
Uncertainty Analyst
Southampton Oceanography Centre
European Way, Southampton SO14 3ZH, UK
tel
2006 Feb 22
3
elements that appear only once
Hi.
I have a factor and I want to extract just those elements that appear
exactly once.
How to do this?
Toy example follows.
> a <- as.factor(c(rep("oak",5) ,rep("ash",1),rep("elm",1),rep
("beech",4)))
> a
[1] oak oak oak oak oak ash elm beech beech beech beech
Levels: ash beech elm oak
> table(a)
a
ash beech elm oak
2006 Sep 13
3
functions and strings
Hi
If
string <- "xyz"
f <- function(x){1 + sin(cos(x)) + exp(x^2)}
How do I manipulate "string" and f() to give the string
"1 + sin(cos(xyz)) + exp(xyz^2)"
?
--
Robin Hankin
Uncertainty Analyst
National Oceanography Centre, Southampton
European Way, Southampton SO14 3ZH, UK
tel 023-8059-7743
2005 Nov 17
3
changing figure size in Sweave
Hi
In Sweave, how does one change the size of the plots?
I tried using a hook:
<<echo=FALSE, print=FALSE, fig=TRUE>>=
options(SweaveHooks=list(fig=function() ps.options(width=1)))
library(graphics)
pairs(iris)
@
but this didn't change the size of the figure. How to make the
figures a
different size?
--
Robin Hankin
Uncertainty Analyst
National Oceanography Centre,
2007 Mar 19
3
character to numeric conversion
Hi.
Is there a straightforward way to convert a character string
containing comma-delimited
numbers to a numeric vector?
In my application, I use
system(executable.string, intern=TRUE)
which returns a string like
"[0.E-38, 2.096751179214927596171268230,
3.678944959657480671183123052, 4.976528845643001020345216157,
6.072390165503099343887569007, 7.007958550337542210168866070,
2006 Feb 28
2
lines() and recycled colours
Hi
?lines says
For 'type = "h"', 'col' can be a vector and will be recycled as
needed.
Why doesn't lines() recycle colours for other types?
If I type
> plot(0:1,0:1,type="n")
> lines(runif(11),runif(11),col=c("red","green"))
>
then all ten lines are red, with no warning given. Is there a reason
why
2006 Jul 25
2
pari/gp interface
Hi
I'm developing an R package that
needs to execute some code written in pari/gp.
I've used this before from an R package (elliptic) but the interface
is very
basic: the R function creates a string such as the following:
string <- echo ' ellwp ([ 2+0*I , 0+2*I ], 1+0*I )' | gp -q
And then
system(string)
returns the output from gp which then needs to be text processed
2008 Mar 26
5
S4 slot with NA default
Hi
How do I specify an S4 class with a slot that is potentially numeric,
but NA
by default? I want the slot to be NA until I calculate its value
(an expensive operation, not needed for all applications). When
its value is
known, I will create a new object with the correct value inserted in
the slot.
I want "NA" to signify "not known".
My attempt fails because
2006 Nov 17
2
do.call("+", ...)
Hi
How do I make do.call() take "+" as a function for a list of more
than two elements?
Toy problem follows:
f <- function(i){matrix((1:6)^i,2,3)}
# Thus f() returns a matrix of size 2x3; I want to add a whole bunch
of such matrices,
# as in f(1) + f(2) + f(3) + f(4)
# But:
> do.call("+",sapply(1:4,f,simplify=FALSE))
Error in do.call("+",
2007 Jan 16
5
"[[" gotcha
The following gotcha caught me off-guard just now.
I have two matrices, a and b:
a <- matrix(1,3,3)
b <- matrix(1,1,1)
(note that both "a" and "b" are matrices).
I want them in a list:
> B <- NULL
> B[[1]] <- a
> B[[2]] <- b
> B
[[1]]
[,1] [,2] [,3]
[1,] 1 1 1
[2,] 1 1 1
[3,] 1 1 1
[[2]]
[,1]
[1,] 1
2006 Jul 27
4
inserting rows into a matrix
Hi
I have a little vector function that takes a vector A of strictly
positive integers
and outputs a matrix M each of whose columns is the vector, modified in
a complicated combinatorical way.
Now I want to generalize the function so that A can include zeroes.
Given A,
I want to strip out the zeroes, pass it to my function, and pad M
with rows at positions corresponding to the zeroes