similar to: A matrix automation problem

Displaying 20 results from an estimated 3000 matches similar to: "A matrix automation problem"

2006 Jun 26
2
probably need to se sapply but i can't get it
Hi : I think I need to use sapply but I can't figure this out. Suppose I have two vectors : tempa ( 4, 6,10 ) and tempb ( 11,23 ,39 ) I want a function that returns 4:11,6:23 and 10:39 as vectors. I tried : sapply(1:length(tempa) function (z) seq(tempa[z],tempb[z]) but i got 3 really strange vectors back in the sense that the numbers in them did not make no sense to me. obviously, i
2007 May 04
2
Analysis for Binary time series
hi, hi, good morning everyone. I have a time series with binary outputs like : 0001011110100.................etc. Now I want to forecast the future values of that. Can anyone please tell me whether there is any tools exist in literature for dealing with this kind of binary observation? If possible please provide me some good references in net as well. rgd, Megh
2006 Nov 16
1
getting a title in a plot during an lapply
In my code below tempa and tempb are numeric vectors that I combined into a dataframe along with the deciles of tempa. I have an lapply statement that goes through the dataframe and does ten plots according to the appropriate decile. The code is below and it works fine. There are no bugs so I figure there was no need to include structure statements on the data. Also, I don't want to use coplot
2012 May 30
1
caret() train based on cross validation - split dataset to keep sites together?
Hello all, I have searched and have not yet identified a solution so now I am sending this message. In short, I need to split my data into training, validation, and testing subsets that keep all observations from the same sites together ? preferably as part of a cross validation procedure. Now for the longer version. And I must confess that although my R skills are improving, they are not so
2011 Aug 01
4
Use dump or write? or what?
Greetings all, I am calculating two t-test values for each of many files then save it to file calculate another set and append, repeat. But I can't figure out how to write it to file and then append subsequent t-tests. (maybe too tired ;} ) I have tried to use "dump" and "file.append" to no avial. ttest_results = tempfile() two_sample_ttest <- t.test (tempA, tempB,
2006 Jun 27
1
related to my previous sapply question]
in my previous post in which i asked about creating sequences from two vectors of numbers, all suggestions worked. tradevectors<-mapply(seq,from=tempa,to=tempb) or tradevectors<-sapply(1:length(tempa),function(x) seq(tempa[x],tempb[x]) >both return a list with 3 components. the problem is that i want to take these 3 sequences and use them as the indices of two other vectors, X and
2008 Jun 04
2
converting a table to a dataframe or a matrix
can someone show me how to convert a table to a data.frame or a matrix ? I tried below and as.data.frame rearranges the columns similarly to a melt from reshape and as.matrix didn't change it. I actually would prefer to change it to a dataframe but if someone can show me how to convert it to a matrix, then as.data.frame will work on that. I was thinking about just changing the class to
2006 Jun 28
2
hopefully my last question on lapply
Marc and many other people ( whose names escape me ) have been very helpful in explaining the use of lapply to me. In his last response, Marc explained that if tradevectors is a list of vectors of different lengths ( excuse my terminology ) then lapply(tradevectors,function(x) G[x]*B[x] ) will go through each component of the list as if it was a vector and apply the element by element
2012 Jul 03
2
EM algorithm to find MLE of coeff in mixed effects model
I have a general question about coefficients estimation of the mixed model. I simulated a very basic model: Y|b=X*\beta+Z*b +\sigma^2* diag(ni); b follows N(0,\psi) #i.e. bivariate normal where b is the latent variable, Z and X are ni*2 design matrices, sigma is the error variance, Y are longitudinal data, i.e. there are ni
2008 Mar 23
1
mapply
In an earlier post, a person wanted to divide each of the rows of rawdata by the row vector sens so he did below but didn't like it and asked if there was a better solution. rawdata <- data.frame(rbind(c(1,2,2), c(4,5,6))) sens <- c(2,4,6) temp <- t(rawdata)/sens temp <- t(temp) print(temp) Gabor sent three other solutions and I understood 2 of them but not the
2007 Feb 01
3
Extracting part of date variable
Dear all, Suppose I have a date variable: c = "99/05/12" I want to extract the parts of this date like month number, year and day. I can do it in SPSS. Is it possible to do this in R as well? Rgd, --------------------------------- Here’s a new way to find what you're looking for - Yahoo! Answers [[alternative HTML version deleted]]
2013 Feb 23
1
how to calculate left kronecker product?
For an application, I have formulas defined in terms of a left Kronecker product of matrices, A,B, meaning A \otimes_L B = {A * B[i,j]} -- matrix on the left multiplies each element on the right. The standard kronecker() function is the right Kronecker product, A \otimes_R B = {A[i,j] * B} -- matrix on the right multiplies each element on the left. The example below shows the result of
2005 Dec 08
1
kronecker(... , make.dimnames=TRUE)
Hi I'm using kronecker() with a matrix and a vector. I'm interested in the column names that kronecker() returns: > a <- matrix(1:9,3,3) > rownames(a) <- letters[1:3] > colnames(a) <- LETTERS[1:3] > b <- c(x=1,y=2) > kronecker(a,b,make.dimnames=TRUE) A: B: C: a:x 1 4 7 a:y 2 8 14 b:x 2 5 8 b:y 4 10 16 c:x 3 6 9 c:y 6 12 18 > The
2012 Feb 09
1
Row-wise kronecker product with Matrix package
I'm trying to calculate the row-wise kronecker product A \Box B of two sparse matrices A and B, and am struggling to find a quick way to do this that takes advantage of sparseness. I thought a good idea would be to use "rep" to construct 2 matrices of the same dimension of the end product, and multiply these two together: library(Matrix) A<-Matrix(c(1,0,0,0,0,1,2,0), 2, 4)
2008 Apr 19
4
Displaying external url's
I am a rails beginner and I am having trouble displaying external urls on view. This is what i have in DB for ex: www.rubyonrails.com, if i try to construct the url on the page using link_to the url formed is - http://localhost:3000/www.rubyonrails.com. Can someone help me in fixing this issue. Thanks --~--~---------~--~----~------------~-------~--~----~ You received this message because you
2004 Jan 30
1
How to create own distance measure in cluster ?
Hi everyone, I want to create my own distance measure, other than 'euclidean' or 'manhatan', to use in cluster pckgs. To do this I think that I need to change dist(), in mva pckg, or daisy(), in cluster pckg. (or is there a cleaver way ?) But this functions are in fact things like: .Fortran( "daisy", ... ) or .C("dist",...). I tried unsuccessfully to find
2010 Nov 25
1
Request: kronecker to get a sep= argument
kronecker, with make.dimnames=TRUE uses a hardwired sep=":" in the line tmp <- outer(dnx[[i]], dny[[i]], FUN = "paste", sep = ":") For an application in which dimnames arise from an n-way array, where different dimensions have different roles, and I would like to be able to use kronecker in the form kronecker(A, B, make.dimnames=TRUE,
2008 Oct 11
5
Extracting subset of a vector
I have 2 vecros : x<-c(100,96,88,100,100,96,80,68,92,96,88,92,68,84,84,88,72,88,72,88) x1 = sample(x, 5, replace=FALSE) Now i want to get remaining values of vector "x" those are not member of vector "x1". Can anyone please tell me how to do that?
2011 Jun 05
2
kronecker sum
Dear All, Could someone please suggest how to find the Kronecker sum of two 2x2 matrices, i.e. given two matrices: -A A a -a and -B B b -b I need: -A-B A B 0 a -a-B 0 B b 0 -A-b A 0 b a -a-b Many thanks, Lara [[alternative HTML version deleted]]
2005 Oct 13
3
Help with Matrix package
Hello all, A colleague at work set me the challenge to convert some MATLAB code into R, to see which is faster. We'd seen that benchmark comparing MATLAB 6.5 to R1.90 (and others), and so I thought that I should be able to get roughly comparable speeds. The code has lots of multiplications of matrixes, transposes, and MATLAB's "repmat". I did the code conversion, and R was about