Displaying 20 results from an estimated 60000 matches similar to: "test if vector contains elements of another vector (disregarding the position)"
2012 Jan 21
2
sequentially summing up a elements of a vector
Hi,
I have a somewhat abstract and tricky problem (at least for me).
Perhaps someone here can help me:
I would like to convert:
x <- c(0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0)
into
x <- c(0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4)
every 1 in x marks kind of a 'border' which is separated in different 'regions' in the
2012 Feb 02
1
get mean of same elements in a data.frame
Hi,
I have the following data.frame:
data.frame(x = c(1:10), y = rnorm(10,2,1), label = rep(c('a', 'b', 'c', 'd', 'e'),2))
in this data.frame there is a label-variable containing strings.
Each string is represented two times.
Now I would like to have the mean of the corresponding x (and y-values) for every unique label-element.
For the label
2013 Feb 26
4
cut a vector in equal parts
Hi,
I would like to cut a vector of values in parts.
Each part should have an equal number of elements.
for example:
x <- (rnorm(500)^2)
now I want 5 vectors each with 100 elements.
The first vector should include the 100 lowest values of x and so on
(so that the fifth vector contains the 100 highest values of x).
thanks for any help!
2009 Sep 23
2
Function to check if a vector contains a given value?
Dear R'rs,
is there a function that checks if a given vector contains a certain value.
E.g., x<-c(1,2,3,4).
How can I get a TRUE or FALSE for whether x contains a 2?
--
Dimitri Liakhovitski
Ninah.com
Dimitri.Liakhovitski at ninah.com
2011 Oct 10
1
calculate multiple means of one vector
Dear R-Users,
I have the following two vectors:
data <- rnorm(40, 0, 2)
positions <- c(3, 4, 5, 8, 9, 10, 20, 21, 22, 30, 31, 32)
now I would like to calculate the mean of every chunk of data-points (of the data-vector) as defined by the positions-vector.
So I would like to get a vector with the mean of element 3 to 5 of the data-vector, 8 to 10, 20 to 22 and so
2010 Feb 09
3
split strings in a vector and convert it to a data.frame
hi,
I have a vector full of strings like;
xy_100_ab xy_101_ab xy_102_ab xy_103_ab
I want to seperate each string in three pieces and the separator should be the "_"
at the end I want a data.frame like:
column1 column2 column3
xy 100 ab
xy 101 ab
xy 102 ab
xy 103 ab
I tried strsplit but I couldn't figure out how to convert the list I get into a data.frame.
I just
2011 Sep 09
3
split variable / create categories
Hi,
is there a function or an easy way to convert a variable with continuous values into a categorial variable (with x levels)?
here is what I mean:
I want to transform x:
x <- c(3.2, 1.5, 6.8, 6.9, 8.5, 9.6, 1.1, 0.6)
into a 'categorial'-variable with four levels so that I get:
[1] 2 2 3 3 4 4 1 1
so each element is converted into its rank- value / categorial-value
(in
2011 Oct 05
2
mean of 3D arrays
Hi,
I have multiple three dimensional arrays.
Like this:
x1 <- array(rnorm(1000, 1, 2), dim=c(10, 10, 10))
x2 <- array(rnorm(1000, 1, 2), dim=c(10, 10, 10))
x3 <- array(rnorm(1000, 1, 2), dim=c(10, 10, 10))
Now I would like to compute the mean for each corresponding cell.
As a result I want to get one 3D array (10 x 10 x 10) in which at position x, y, z is the mean of the
2012 Dec 25
5
aggregate / collapse big data frame efficiently
Hi,
I need to aggregate rows of a data.frame by computing the mean for rows with the same factor-level on one factor-variable;
here is the sample code:
x <- data.frame(rep(letters,2), rnorm(52), rnorm(52), rnorm(52))
aggregate(x, list(x[,1]), mean)
Now my problem is, that the actual data-set is much bigger (120 rows and approximately 100.000 columns) ? and it takes very very long
2008 Jul 10
2
Position in a vector of the last value > n
This shouldn't be hard, but it's just not
coming to me:
Given a vector, e.g.,
v <- c(20, 134, 45, 20, 24, 500, 20, 20, 20)
how can I get the index of the last value in
the vector having a value greater than n, in
this case, greater than 20? I'm looking for
an efficient function I can use on very large
matrices, as the FUN argument in the apply()
command.
Confidentiality
2013 Jan 11
3
aggregate data.frame based on column class
Hi,
When using the aggregate function to aggregate a data.frame by one or more grouping variables I often have the problem, that I want the mean for some numeric variables but the unique value for factor variables.
So for example in this data-frame:
data <- data.frame(x = rnorm(10,1,2), group = c(rep(1,5), rep(2,5)), gender =c(rep('m',5), rep('f',5)))
aggregate(data,
2010 Feb 25
1
Accessing named elements of a vector
Dear R developers,
A great R feature is that elements of vectors, lists and dataframes can
have names:
vx = c(a=1, b=2)
lx = list(a=1, b=2)
Accessing element "a" of vx: vx['a']
Accessing element "a" of lx: lx[['a']] or lx$a
Might be a matter of taste, but I like the $ very much. Unfortunately,
vx$a is not
functional. Would it break existing compatibility
2011 Oct 05
3
do calculations as defined by a string / expand mathematical statements in R
Dear R-group,
is there a way to perform calculations that are defined in a string format?
for example I have different variables:
x1 <- 3
x2 <- 1
x4 <- 1
and a string-variable:
do <- 'x1 + x2 + x3'
Is there any way to perform what the variable 'do'-describes
(just like the formula-element but more elemental)?
Perhaps my idea to solve my problem is a little
2012 Jan 29
2
apply lm() to each row of a matrix
Hi,
I would like to fit lm-models to a matrix with 'samples' of a dependent variable (each row represents one sample of the dependent variable).
The independent variable is a vector that stays the same:
y <- c(1:10)
x <- matrix(rnorm(5*10,0,1), 5, 10)
now I would like to avoid looping over the rows, since my original matrix is much larger;
for(t in 1:dim(x)[1]) {
2009 Jul 11
2
mann-whitney U-test - U-value
Hi,
I know that I can perform a Mann-Whitney U test with wilcox.test(x,y)
But instead of an U-value I get a W-Value.
Is it possible to change this?
2009 Nov 18
2
error message; ylim + log="y"
Hi,
I get a lot of error messages with this command, but I don't understand why;
plot(c(),c(), xlim=c(1,10), ylim=c(0,10000), log="y")
thanks for any help!
[[alternative HTML version deleted]]
2009 Mar 05
3
text at the upper left corner outside of the plot region
Hi,
is there a way to place text at the upper left corner (or another
corner) of the plot?
I want to place it really at the upper left corner of the whole plot
(the file I get),
not at the upper left corner of the plot-region.
I tried text() and mtext(), and corner.label() of the plotrix package
but it didn't work out.
thanks!
2011 Oct 11
2
replicate data.frame n times
Hi,
is there a way to replicate a data.frame like you can replicate the entries of a vector (with the repeat-function)?
I want to do this:
x <- data.frame(x, x)
(where x is a data.frame).
but n times.
And it should be as cpu / memory efficient as possible, since n is pretty big in my case.
thanks for any suggestions!
2008 Mar 14
2
Selecting elements in vector
Hi
Consider the following code
> x <- rep(1:13, 13)
> y <- 1:3
I want to select all elements in x which are equal to 1, 2 or 3.
I know that I could use
> sel <- x==y[1] | x==y[2] | x==y[3]
> x[sel]
to obtain the values, but in my analysis, the y-vector is thousands of
elements long.
Is there any way, that I can do that easily?
Thanks
Rainer
--
Rainer M. Krug, Dipl.
2008 Feb 12
3
reverse vector elements
Dear lists,
I want to write a function of a vector and reverse the order of its elements. Here is my code:
revector<-function(n){
y=vector(length=n)
for(i in n:1){
y[i]=i
}
return(y)
}
i want my output to be like this:
y
[1] 10 9 8 7 6 5 4 3 2 1
Any suggestion?? Thanks!!
Cheers,
Anisah
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