Displaying 20 results from an estimated 20000 matches similar to: "any suggestions on this error?"
2009 Apr 05
3
number of zeros in a matrix -row by row
Hi. I have an n x m matrix M some of who's entries are zeros. I want to know
how many zeros there are in each row -perhaps stored in a 1 x n vector
which lists the number of zeros for each row of M.
Before I had a vector V and I was able to get the number of zeros in V by
doing length(V[ V==0]) but when I try something similar for M, like M[ M==0]
it creates a vector not a matrix and so
2007 Jan 19
4
Vectorize rearrangement within each column
Consider a matrix like
> ma = matrix(10:15, nr = 3)
> ma
[,1] [,2]
[1,] 10 13
[2,] 11 14
[3,] 12 15
I want to rearrange each column according to row indexes (1 to 3)
given in another matrix, as in
> idx = matrix(c(1,3,2, 2,3,1), nr = 3)
> idx
[,1] [,2]
[1,] 1 2
[2,] 3 3
[3,] 2 1
The new matrix mb will have for each column the
2008 Feb 01
6
Accessing the elements of a list
Hi R,
I wanted to know how do we access the elements of a list. In particular,
v=list(c(1,2,3,4,5),c(1,2,33,4,5),c(1,2,333,4,5),c(1,2,3333,4,5))
I want to access all the thirds items of the elements of the list. i.e.,
I want to access the elements, 3,33,333,3333. This can be done through
sapply as:
sapply(v,function(x) x[3])
But I need to access this without using
2005 Dec 21
3
NextMethod causes R 2.2.0 to crash (PR#8416)
I found writing the following default method the for the generic
function "julian" causes R to crash.
julian.default <- function(x, ...) {
x <- as.Date(x)
NextMethod("julian", x, ...)
}
Here is a test example
> m <- as.Date("1972-09-27") + 0:10
> m
[1] "1972-09-27" "1972-09-28" "1972-09-29"
2008 Feb 13
2
apply on large arrays
I have a big contingency table, approximately of size 60*2*500*500,
and I need to count the number of cells containing a count of 1 for each
of the factors values defining the first dimension.
Here is my attempt:
tab1<-with(pisa1,table(CNT,GENDER,ISCOF,ISCOM))
tab2<-apply(tab1,1:4,function(x)ifelse(sum(x)==1,1,0))
tab3<-apply(tab2,1,sum)
Computing tab2 is very slow.
Is there a faster
1999 Mar 17
1
hist(list)?
It seems that the following should work:
> x<-read.table('1A.tab',header=T,skip=1);
> mode(x[1])
[1] "list"
> x[1]
p01
R1-00 0.0295
R1-01 0.0283
R1-02 0.0145
R1-03 0.0235
R1-04 0.0339
R1-05 0.0239
R1-06 0.0414
R1-07 0.0259
> hist(x[1])
Error: hist: x must be numeric
> as.numeric(x[1])
Error: (list) object cannot be coerced to vector type 14
>
2006 Dec 22
5
substitute creates an object which prints incorrectly (PR#9427)
The function "substitute" seems to fail to make a genuine
substitution, although the printed verision seems fine. Here is an
example.
> m <- substitute(Y <- function(x) FUN(x+1),
+ list(Y = as.name("y"), FUN = as.name("sin")))
> m
y <- function(x) sin(x + 1)
> eval(m)
> y
function(x) FUN(x+1)
However the story doesn't end there. The
2005 Apr 30
3
as.numeric method for objects of class "difftime"
I have just become painfully aware that objects of class "difftime",
generated by the difference of two POSIXct objects, carry a "units"
attribute, which flashes by when the object is printed, for example.
The pain was occasioned when I tried to turn these objects into numberic
objects for use elsewhere as a covariate.
as.numeric(difftime object)
simply turns off the units
2007 Jul 03
1
termplot - changes in defaults
While termplot is under discussion, here's another proposal. I'd like to
change the default for partial.resid to TRUE, and for smooth to
panel.smooth. I'd be surprised if those changes were to break existing
code.
John Maindonald email: john.maindonald at anu.edu.au
phone : +61 2 (6125)3473 fax : +61 2(6125)5549
Centre for Mathematics & Its Applications, Room
2009 Mar 31
4
Convert Character to Date
Hello,
I have a date in the format Year-Month Name (e.g. 1990-January) and R classes it as a character. I want to convert this character into a date format, but when I try as.Date(1990-January, "%Y-%B"), I get back NA. The function strptime also gives me NA back. Thanks.
[[alternative HTML version deleted]]
2007 Nov 06
1
A suggestion for an amendment to tapply
Dear R-developers,
when tapply() is invoked on factors that have empty levels, it returns
NA. This behaviour is in accord with the tapply documentation, and is
reasonable in many cases. However, when FUN is sum, it would also
seem reasonable to return 0 instead of NA, because "the sum of an
empty set is zero, by definition."
I'd like to raise a discussion of the possibility of an
2001 Feb 01
1
constructing a vector from a dataframe and another vector
Hi All,
I have a dataframe, divs, that looks like this:
> divs
date ticker dividend
263 20010322 ADBE 0.025
264 20010628 ADBE 0.025
265 20010927 ADBE 0.025
4308 20010212 ED 0.550
4309 20010514 ED 0.410
5416 20010330 GE 0.137
5417 20010629 GE 0.137
5418 20010928
2006 Jan 14
2
initialize expression in 'quasi' (PR#8486)
This is not so much a bug as an infelicity in the code that can easily
be fixed.
The initialize expression in the quasi family function is, (uniformly
for all links and all variance functions):
initialize <- expression({
n <- rep.int(1, nobs)
mustart <- y + 0.1 * (y == 0)
})
This is inappropriate (and often fails) for variance function
"mu(1-mu)".
2000 Oct 02
9
the underscore ("_") in variable name
At 14:35 02/10/00 +0800, mohd zamri wrote:
>new to R and starting to learn to program R. The underscore ("_") did some
>suprising result. e.g
>
>> c <- c(1,2,3,4,5)
>> mean(c)
>[1] 3
>> c_mean <- mean(c)
>> c
>[1] 3
>
>having some experience in C, I thought the underscore is "always" valid in
>variable name. totally confuse
2007 Nov 15
3
generate combination set
I have a set data={A,B,C,D,E,F,G}
I want to choose 2 letter from 8 letters, i.e. generate the combination set
for choose 2 letters from 8 letters.
I want to get the liking:
combination set={AB,AC,AD,....}
Does anyone konw how to do in R.
thanks,
Aimin
2001 Jul 09
1
polynomial regression and poly
When doing polynomial regression I believe it is a good idea to use the poly
function to generate orthogonal polynomials. When doing this in Splus there
is a handy function (transform.poly I think) to convert the coefficients
produced by regression with the poly function back to the original scale.
Has somebody written something similar for R ?
Robert
2008 Mar 04
6
vector manipulations
Un texte encapsul? et encod? dans un jeu de caract?res inconnu a ?t? nettoy?...
Nom : non disponible
Url : https://stat.ethz.ch/pipermail/r-help/attachments/20080304/9de37092/attachment.pl
2000 May 25
1
diag() (PR#555)
Full_Name: David Duffy
Version: 1.0.1
OS: Linux
Submission from: (NULL) (152.98.96.21)
Documentation for diag() states that "If x is a vector (or a
1-d array) then diag(x) returns a diagonal matrix whose diagonal
is x."
> m<-matrix(1:4,ncol=1)
> diag(m)
[1] 1
diag(as.vector(m)) gives the advertised performance.
Fix: Change documentation.
2001 Nov 01
1
cor.test for a correlation matrix
Is there a simple way to run cor.test on for a matrix of correlations?
Of course, cor on a data frame produces a correlation matrix, but cor.test will only take two variables at a time. Is there a way to get behavior similar to that of cor with cor.test?
I suppose the programming alternative would be to run two for loops with the number of items and cor test embedded accessing the columns of
2000 Mar 07
1
A simple question??
Dear all,
I'm currently use R v0.99 on Windows 98 Second Edition. I have a question on some simple calculations. I wonder that I've done something wrong with the calculation.
Here is the imput commands:
> a <- 25.01
> b <- 56.08
> a.trunc <- trunc(a)
> b.trunc <- trunc(b)
> a.tail <- a - a.trunc
> b.tail <- b - b.trunc
> a.trunc
[1] 25
>