Displaying 20 results from an estimated 60000 matches similar to: "Isomorphic matrices"
2012 Nov 11
2
changing the signs in rows or columns in matrices and check them if they are identical
Dear R users,
i have this problem with matrices i want to check between two matrices if they are isomorphic i will give an example for what excactly i want
1 -1 1 -1 1 1
-1 1 -1 1 -1 -1
1 1 -1 1 1 -1
this two matrices are isomorphic beacause if i change the first 2 columns the matrices
2012 Oct 30
5
Swap rows and columns in a matrix
Dear R users,
I want a help to write an algorithm for swapping rows and columns in a matrix
thanks in advance
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2012 Oct 29
0
Check Isomorphism between matrices
I have 3003 16x5 submatrices from a hadamard matrice of 16x15. I want to write an algorithm that check all of these 3003 matrices if they are isomorphic and i want to find and keep the non-isomorphic ones. Any help will be welcome.
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2012 Nov 12
2
Selected matrices of an array and put into a list
Dear R users,
I have an array that has matrices that i want BB[16,5,2:27]
i want to put each of the 26 matrices into a List
thanks in advance
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2012 Nov 11
0
Changing the signs in rows or columns in matrices and check the matrices if they are identical
i have this problem with matrices i want to check between two matrices if they are isomorphic i will give an example for what excactly i want
1 -1 1 -1 1 1
-1 1 -1 1 -1 -1
1 1 -1 1 1 -1
this two matrices are isomorphic beacause if i change the first 2 columns the matrices are identical
2012 Nov 18
1
identical matrices
Dear R users,
I want to check matrices when i change the order of the rows or/and the order of the columns or/and the combination of them
i will give an example what i want
1 -1 1 1 1 1 1 1
-1 -1 -1 -1 -1 -1 -1 -1
1 1 1 1 1 -1 1 1
these 2 matrices are identical because i change the first row and make it third
1 -1 1 1 -1 1 1 1
-1 -1 -1
2012 Nov 13
2
multiply each row in a matrix with the help of the for loop
Dear R users,
I have this program
aa<-array(rep(0,27),dim=c(3,3,3))
a<-matrix(rep(1,9),ncol=3)
n<-0
for (i in 1:3) {
a[i,]<-a[i,]*(-1)
n<-n+1
aa[,,n]<-a[i,]
}
but i real want to multiply each row with -1 according to for loop and after that to put it in the array.
I will give an example for what excaclty want
-1 -1 -1
1 1 1
1 1 1
-1 -1 -1
-1
2012 Oct 30
2
Put submatrices in an array
Dear R users,
I have a Hadamard matrix 16x15 and i want to put 16x5 submatrices in an array put i have an error.
> A1<-matrix(c(0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+ 1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,
+ 0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,
+ 1,1,0,0,1,1,0,0,1,1,0,0,1,1,0,
+ 0,0,0,1,1,1,1,0,0,0,0,1,1,1,1,
+ 1,0,1,1,0,1,0,0,1,0,1,1,0,1,0,
+ 0,1,1,1,1,0,0,0,0,1,1,1,1,0,0,
+ 1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,
+
2012 Nov 05
3
Error message
Dear R users,
I have this problem with memory i guess
AA<-array(rep(0,96096000),dim=c(16,5,3003,400))
Error: cannot allocate vector of size 733.2 Mb
can anyone help me,
Thanks in advance...
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2009 Sep 19
1
Converting matrices into row vectors and saving as ASCII text
Hi
I have some data with these dimensions:
5 3 100
which correspond to the x, y, and time dimensions, for a variable, p.
I need the data in this format: 100 rows (1 row per time unit), and 15
values in each row.
I have attempted to reshape my data
>dim(data)
5 3 100
>attr(data,'dim')<-c(dim(data)[3],dim(data)[1]*dimdata[2])
So I get data with 100 rows, 15 columns.
I need
2012 Feb 13
1
non-isomorphic sequences
Dear All,
Sorry for the typoes earlier, let me repost the question.
Suppose I want to generate sequences of length 3 from two symbols {1,2}, we get the following 8 sequences
1 1 1
1 1 2
1 2 1
1 2 2
2 1 1
2 1 2
2 2 1
2 2 2
However, I do not want all these 8 sequences. I call two sequencs to be isomorphic if one sequence could be obtained from the other by relabelling the symbols. For example,
2007 Aug 09
1
How to apply functions over rows of multiple matrices
Dear ExpRts,
I would like to perform a function with two arguments
over the rows of two matrices. There are a couple of
*applys (including mApply in Hmisc) but I haven't found
out how to do it straightforward.
Applying to row indices works, but looks like a poor hack
to me:
sens <- function(test, gold) {
if (any(gold==1)) {
sum(test[which(gold==1)]/sum(which(gold==1)))
} else NA
}
2009 Aug 22
3
Help on comparing two matrices
Hi,
I need to compare two matrices with each other. If you can get one of
them out of the other one by resorting the rows and/or the columns, then
both of them are equal, otherwise they're not. A matrix could look like
this:
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8]
[1,] 0 1 1 1 0 1 1 0
[2,] 1 1 0 0 0 1 0 1
[3,] 1 0 1 0 0
2005 Apr 29
0
handling of zero and negative indices in src/main/subscript.c:mat2indsub() (PR#7824)
This message contains a description of what looks like a bug, examples
of the suspect behavior, a proposed change to the C code to change this
behavior, example of behavior with the fix, and suggestions for 3 places
to update the documentation to reflect the proposed behavior. It is
submitted for consideration for inclusion in R. Comments are requested.
Currently, the code for subscripting
2005 May 06
0
(PR#7824) handling of zero and negative indices in
I've put this in (with some different wording). Although S blithely
accepts mis-dimensioned index matrices I agree this is wrong and have made
it an error.
On Fri, 29 Apr 2005 tplate@acm.org wrote:
> This message contains a description of what looks like a bug, examples
> of the suspect behavior, a proposed change to the C code to change this
> behavior, example of behavior with
2007 Aug 10
1
[Fwd: Re: How to apply functions over rows of multiple matrices]
[Apologies to Gabor, who I sent a personal copy of the reply
erroneously instead of posting to List directly]
[...]
> Perhaps what you really intend is to
> take the average over those elements in each row of the first matrix
which correspond to 1's in the second in the corresponding
> row of the second. In that case its just:
>
> rowSums(newtest * goldstandard) /
2007 Oct 09
1
Handling two lists of matrices
I'm having trouble setting up the function call to handle two lists of
matrices. Each list has 6 matrices - Each matrix is 20x10. I need to
do some basic math on corresponding matrices in each list.
Here are some outputs of these lists, etc...
# first list
> length(qc.pm)
[1] 6
> dim(qc.pm[[1]])
[1] 20 10
> qc.pm[[1]][1:4,1:4]
441-JP071707.CEL 442-JP071707.CEL
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
2010 Apr 27
5
get means of elements of 5 matrices in a list
I've got a list of 5 matrices that are each 5 x 6. I'd like to end up with a
5 x 6 matrix that contains the mean value of the 5 original matrices. I can
do this by brute force, but there must be a better way than making each
matrix into a vector and then remaking a matrix
thanks very much for any help
david freedman
ll=list(structure(c(9.7, 17.6, 20.8, 24.1, 33.8, 14.5, 25.7, 29.8,
2013 Feb 14
3
list of matrices --> array
i'm somehow embarrassed to even ask this, but is there any built-in
method for doing this:
my_list <- list()
my_list[[1]] <- matrix(1:20, ncol = 5)
my_list[[2]] <- matrix(20:1, ncol = 5)
now, knowing that these matrices are identical in dimension, i'd like
to unfold the list to a 2x4x5 (or some other permutation of the dim
sizes) array.
i know i can initialize the array, then