Displaying 20 results from an estimated 20000 matches similar to: "logical or for two vectors or matrices"
2007 Jan 30
5
how to join two arrays using their column names intersection
Dear all,
I have a problem that may be someone of you can help. I am a newbie and
do not find how to do it in manuals.
I have two arrays, for example:
ar1 <- array(data=c(1:16),dim=c(4,4))
ar2 <- array(data=c(1:16),dim=c(4,4))
colnames(ar1)<-c("A","B","D","E")
colnames(ar2)<-c("C","A","E","B")
> ar1
2008 Jun 02
4
exit function in R?
Hi,
This is likely an stupid question, but I cannot find the solution.
I am searching for an "exit" function, to end the execution of an R
script if some condition is not filled.
Any clue?
Thank you in advance!
Federico
2009 Oct 29
3
x-y plot as an histogram
Hi,
I am investigating a problem for which I found no solution.
I have a matrix with two columns. I have plotted it as an x-y plot
(plot(matrix[,1],matrix[,2])
But this is not apropriate for my purposes. I need to group the data
in matrix[,1] into groups (as an histogram would do). Then I have to
calculate the average of matrix[,2] for each group.
Before starting with loops and loops I
2007 May 04
2
Get the difference between two matrices with different length
Hello,
I have got two matrices with different length. The matrices have 3
columuns. The first two are coordinates. The third is a measurement.
Now I want to get a subtraction between every single value of the
third column (between matrix1 and matrix2), but only if the two
first coordinates in matrix1 and matrix2 are the same.
I tried "FUN=?" in aggregate and ave, but I don't know
2007 Feb 14
2
font size in plots
Dear members of the list,
it is likely a stupid question but I cannot find the information neither
in R manuals nor in google.
I am generating a plot (from hclust results) but I cannot see properly
the labels because the default font size is too large. How can I change it?
Thanks!
Federico
2008 Mar 13
2
joining matrices, vectors, scalars in one object
Hi,
I have:
a <- matrix(c(0,1,0,1),nrow=2)
b <- matrix(c(1,1,1,0,0,0),nrow=3)
c <- 1
d <- c(1,0,1)
And I would like to join them in an object 'thing' so that I can
access a, b, c, or d through an index in a for loop.
For example:
thing[4]
would return
[1] 1 0 1
Note however, that I have many of these 'thing' components. So many
that a command like
thing
2005 Feb 21
5
Compare rows of two matrices
Hello,
#I have two matrices, eg.:
y <- matrix( c(20, NA, NA, 45, 50, 19, 32, 101, 10, 22, NA, NA, 80, 49, 61, 190), ncol=4 )
x <- matrix( c(20, NA, NA, NA, 50, 19, 32, 101, 10, 22, NA, NA, 80, 49, 61, 190), ncol=4 )
#Whereas x contains all NA?s from y plus some additional NA?s.
#I want to find the index of these additional NA?s. I think, there must be a very
2006 Jun 07
3
smoothing plot(x, type ='l')
Hi All,
I am using plot(x, type = 'l') for some plotting, but I would like rounded edges
rather than jagged edges in the plot (purely for aestetic reasons).
How could I achieve that?
Cheers,
Federico
--
Federico C. F. Calboli
Department of Epidemiology and Public Health
Imperial College, St Mary's Campus
Norfolk Place, London W2 1PG
Tel +44 (0)20 7594 1602 Fax (+44) 020
2007 Apr 26
1
comparing two matrices, row by row
Estimated people,
I have two matrices:
ar1 <- array(data=c(1:16),dim=c(4,4))
ar2 <- array(data=c(1,2,3,3,5:16),dim=c(4,4))
They only differ in the fourth row. I would like to compare them in order to know which columns are equal.
The following works, but I would like to have a better solution, and not to use what someone called "prehistorical loops":
for(i in
2006 Jul 06
3
Comparing two matrices
hi:
I have matrix with dimensions(200 X 20,000). I have
another file, a tab-delim file where first column
variables are row names and second column variables
are column names.
For instance:
> tmat
Apple Orange Mango Grape Star
A 0 0 0 0 0
O 0 0 0 0 0
M 0 0 0 0 0
G 0 0 0 0 0
S 0 0 0 0 0
2006 Sep 26
5
putting stuff into bins...
Hi All,
I have a vector of data, a vector of bin breakpoints and I want to put my data
in the bins and then extract fanciful informations like the mean value of each bin.
I know I can write my own function, but I would have thought that R should have
somewhere a function that took as arguments something like (data, breaks, what
to do with the data in the bins). I surey could not find it
2007 Jul 18
2
EM unsupervised clustering
Hi All,
I have a n x m matrix. The n rows are individuals, the m columns are variables.
The matrix is in itself a collection of 1s (if a variable is observed for an
individual), and 0s (is there is no observation).
Something like:
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 1 0 1 1 0 0
[2,] 1 0 1 1 0 0
[3,] 1 0 1 1 0 0
[4,] 0 1 0
2006 Jun 27
1
Adding elements of matrices of different dimensions
If I have two matrices:
> a<-matrix(1:5,ncol=1)
[,1]
[1,] 1
[2,] 2
[3,] 3
[4,] 4
[5,] 5
> b<-matrix(1:50,ncol=10)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 1 6 11 16 21 26 31 36 41 46
[2,] 2 7 12 17 22 27 32 37 42 47
[3,] 3 8 13 18 23 28 33 38 43 48
[4,] 4 9 14 19
2005 Mar 16
8
Summing up matrices in a list
Dear all,
I think that my question is very simple but I failed to solve it.
I have a list which elements are matrices like this:
>mylist
[[1]]
[,1] [,2] [,3]
[1,] 1 3 5
[2,] 2 4 6
[[2]]
[,1] [,2] [,3]
[1,] 7 9 11
[2,] 8 10 12
I'd like to create a matrix M<-mylist[[1]]+mylist[[2]]
[,1] [,2] [,3]
[1,] 8 12 16
[2,] 10 14 18
2008 Jan 31
3
fastest way to compute the squared Euclidean distance between two vectors in R
I have a program which needs to compute squared Euclidean distance
between two vectors million of times, which the Rprof shows is the
bottleneck. I wondered if there is any faster way than my own simple
function
distance2 = function(x1, x2)
{
temp = x1-x2
sum(temp*temp)
}
I have searched the R-help archives and can not find anything except
when the arguments are matrices. Thanks for any
2008 Jun 04
4
sum of unknown number of matrices
Hi R,
I have a list of matrices. I need to get the sum of all the matrices in
the list.
Example:
a=b=c=d=matrix(1:4,2,2)
l=list(a,b,c,d)
I need:
> a+b+c+d
[,1] [,2]
[1,] 4 12
[2,] 8 16
Something like do.call("+",l) is not working...why is this?
I may not be knowing the number of matrices in the list...
Thanks, Shubha
This e-mail
2005 Nov 21
3
Comparing rows of matrices with different dimensions
Hi there,
I have a question, which I thought is very easy to solve, but somehow I can't find a solution. Probably someone could help me quickly?
Here it is:
I have two matrices:
a
[,1] [,2] [,3]
[1,] 1 4 9
[2,] 2 6 10
[3,] 3 6 11
[4,] 4 8 12
b
[,1] [,2]
[1,] 1 4
[2,] 2 5
[3,] 3 6
Now I want to find
2004 May 12
2
Extracting data from matrices
Dear R list
I have an m * n matrix P and a vector V of length n containing indices for
rows in P.
For each of the m columns I want to extract the value in the row specified
by V, and put these values into a new vector W of length n.
At present I am doing this with a for.... loop, but I imagine there is a faster
way that doesn?t involve loops.
If anyone knows the way I would be most grateful.
2005 Jan 14
3
summing subsets of rows matrices
I have a large data matrix (4460X3500) and I want to sum row subsets in groups of 10 (bin). Is there an efficient way to do this in R without using loops. Looping takes forever to perform this task!
For example suppose we have the matrix
> matrix(1:12,6,2)
[,1] [,2]
[1,] 1 7
[2,] 2 8
[3,] 3 9
[4,] 4 10
[5,] 5 11
[6,] 6 12
my problem is to sdum for
2006 Feb 28
4
subsetting a list of matrices
Hi All,
I have a list of matrices:
> x
[,1] [,2]
[1,] 1 4
[2,] 2 5
[3,] 3 6
> y
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 18 21 24 27 30 33
[2,] 19 22 25 28 31 34
[3,] 20 23 26 29 32 35
> z =list(x,y)
I want to create a second list that is has a subset each matrix in the
list subsetting so I get the 2nd and 3rd row of each (and