search for: matric

Dear all, I am finding difficulty in the following, I would like to create an empty matrix e.g. 10x10 of 0s and sequentially fill this matrix with randomly placed a 1s until it is saturated. Producing 100 matrices of sequentially increasing density., This process needs to be randomized 1000 times., I assume i should run this along the following lines, 1) Create 1000 matrices all zeros, 2) add a random 1 to all matrices, 3) run function on all 1000 matrices and output results to a vector table (i.e. cal...

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...

I have a large list of matrices and a vector that identifies the desired matrices that I would like to rbind. However, I am stuck on how to get this to work. I have written some code below to illustrate my problem: # 3 simple matrices a<-matrix(1:9,3,3) b<-matrix(10:18,3,3) c<-matrix(19:27,3,3) #this is the type of...

Hi, I'm new to programming, new to R and even new to mailing lists so please be patient with me. I need to manage many matrices generated by an R program. These matrices have different dimensions and I'd like to group them somehow. The best way would be to have a big matrix (let's call it database) where every element database[x,y] consists of a list of matrices that all have the dimensions ncol(matrix1)=x and...

....32 DIPLOMA 11121 2.91 DIPLOMA 11122 2.90 DIPLOMA 12131 2.89 DIPLOMA 12132 2.89 DIPLOMA 13141 2.93 DIPLOMA 13142 2.96 DIPLOMA 14151 2.76 DIPLOMA 14152 2.73 STPM ENTRY 2.77 STPM 11121 3.26 STPM 11122 3.30 STPM 12131 3.28 STPM 12132 3.27 STPM 13141 3.28 STPM 13142 3.28 STPM 14151 3.30 STPM 14152 3.31 MATRIC ENTRY 2.93 MATRIC 11121 2.69 MATRIC 11122 2.79 MATRIC 12131 2.81 MATRIC 12132 2.80 MATRIC 13141 2.77 MATRIC 13142 2.76 MATRIC 14151 2.78 MATRIC 14152 2.82 STAM ENTRY 2.00 STAM 11121 3.05 STAM 11122 2.99 STAM 12131 2.97 STAM 12132 2.89 STAM 13141 2.84 STAM 13142 2.79 STAM 14151 2.79 STAM 14152 2.77...

Dear all, I am currently working on the calculation of eigenvalues (and -vectors) of large matrices. Since these are mostly sparse matrices and I remember some specific functionalities in MATLAB for sparse matrices, I started a research how to optimize the calculation of eigenvalues of a sparse matrix. The function eigen itself works with the LAPACK library which has no special handling for...

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...

I have two symmetric matrices, but of different dimensions. The entries are identified by specific labels some of which are shared by both matrices. I would like to sum the two matrices, but retain the union of the two. In other words, I want the result to be the same size as the larger of the two matrices, but with the en...

I'd like to have a three dimensional array of matrices. I thought I could construct a five dimensional array to have the three dimensional array of matrices. However, not all of the matrices in the array have the same dimensions, which seems to mean I can't use a five dimensional array. What I'd like is this: A = matrix(1:4,2,2) B = matr...

...(d*k) matrix which changes in time and A is a constant in time (d*d) matrix. I have put all my X_t in a three dimensional array X of dimension (d,k,T). At the moment for computing the sum over time I'm doing a for loop and saving the resulting (k*k) matrix in a list and at the end I sum the T matrices in this list. I'm wondering if there is a better way to do this. Here an example of what I have to do: *d=3 k=2 T=4 X = array(rnorm(d*k*T),dim=c(d,k,T)) A = matrix(rnorm(d*d),d,d) e1 = list() for (t in 1:T){ #I would like to avoid this e1[[t]] = t(X[,,t])%*%A%*%X[,,t] } ##########...

Dear, I have a data frame melted from a list of matrices (melt from reshape package), then I impute some missing values and then want to tabulate the data again to the array (or list, doesn't matter) of matrices form. However when using xtabs function it orders my rows alphabetically and apparently doesn't take "reorder = FALSE" optio...

Hi Now a more theoretical question. I have two correlation matrices - one of a set of variables under a particular condition, the other of the same set of variables under a different condition. Is there a statistical test I can use to see if these correlation matrices are "different"? Thanks Mick

Hi, Suppose I have these two matrices (could be more). What I need to do is to store these matrices into a hash. So that I can call back any of the matrix back later. Is there a way to do it? > mat_1 [,1] [,2] [1,] 9.327924e-01 0.067207616 [2,] 9.869321e-01 0.013067929 [3,] 9.892814e-01 0.010718579...

To whom it may concern, I am trying to maximize a log-likelihood function using optim. This is a simple problem with only 18 parameters. To conserve memory, I am using sparse matrices (SLAM) for some of the data matrices used in the computation of the likelihood. However, optim appears to convert the sparse matrix back to regular data format. This causes me to run out of memory as R tries to create an 8GB matrix. In short, it does not look as though "optim" is com...

Estimados su ayuda, tengo un total de 20 matrices las cuales deseo colocarlas como componentes de la lista, es decir matrices<-list(matriz1,matriz2,matriz3,...,matriz20) existe alguna manera de hacer esto de manera automatica ya que puede que exista un mayor numero de matrices por ejemplo 100, donde el ingreso de una por una puede resultar u...

hi all. perhaps someone can help me with subsetting here............ i'm trying to use the nested() function in the bipartite package. my problem is that i have a list of 10,000 matrices and i want the output to be a vector of the nested() function on each of the 10,000 matrices (so i can use these numbers in a statistical test). here is what i'm working with currently: #to store 10,000 matrices of null.distr() in listofmatrices listofmatrices <- null.distr(10000,matrix_...

Hi, thank you for taking the time and reading my question. My question is twofold: 1. I have several matrices with variables and one matrix with water levels. I want to predict the water level with the data in the other matrices. Basically, * mod<-lm(matrix1 ~ matrix2+matrix3)* ( What looks like a minus is meant to be the wiggly minus.) Of course I could dissemble the matrices and paste their columns...

Hi, I spotted what looks like another(*) mistake in 'R Language Definition' on how subsetting should work. In Section 'Indexing matrices and arrays' [http://cran.r-project.org/doc/manuals/r-release/R-lang.html#Indexing-matrices-and-arrays] one can read "Negative indices are not allowed in indexing matrices." but this is not true, e.g. > x <- matrix(1:12, nrow=4) > x [,1] [,2] [,3] [1,] 1 5...

Hi, i'm looking to test if two distance matrices are statistically different from each others. These two matrices have been computed on the same set of data (several population samples) 1. using a particular genetic distance 2. weighting that genetic distance with an extra factor (we can look at this as one set is computed before applyin...

Dear Sirs, I would like to ask you, what function can I use for matrices addition? I couldn't find any information about it in the manual or in the internet. (A+B suits, when the number of matrixes is small, function sum() doesn't suit for matrices addition, because it sums all variables in the matrices and produces as an answer single number, not a matrix). I...