[R] dev2bitmap error, 'gs' cannot be found

2008-07-21 Thread Boel Brynedal
ant figure out how to fix this. I am not an experienced programmer. Any help or tips would be greatly appreciated. Thank you, Boel --~*~**~***~*~***~**~*~-- Boel Brynedal, MSc, PhD student Karolinska Institutet Department of Clinical neuroscience __

[R] Efficient distance calculation on big matrix

2012-06-16 Thread Boel Brynedal
Hi All, I'm working on analyzing a large data set, lets asume that dim(Data)=c(1000,8700). I want to calculate the canberra distance between the columns of this matrix, and using a toy example ('test' is a matrix filled with random numbers 0-1): > system.time(d<-as.matrix(dist(t(test), method = "

Re: [R] Efficient distance calculation on big matrix

2012-06-18 Thread Boel Brynedal
Stefan, that looks wonderful! I am most certainly going to try to download and use your 'wordspace', even though I am unsure on how to even download it at this point. Many thanks! But yes, I need the Canberra distance unfortunately. But decreasing the time by more than 60% will save me days! If I c

[R] Problem when creating matrix of values based on covariance matrix

2012-08-11 Thread Boel Brynedal
Hi, I want to simulate a data set with similar covariance structure as my observed data, and have calculated a covariance matrix (dimensions 8368*8368). So far I've tried two approaches to simulating data: rmvnorm from the mvtnorm package, and by using the Cholesky decomposition (http://www.cereb

Re: [R] Problem when creating matrix of values based on covariance matrix

2012-08-11 Thread Boel Brynedal
o > better to post on a stats site like stats.stackexchange.com rather > than here. > > -- Bert > > On Sat, Aug 11, 2012 at 7:17 AM, Boel Brynedal wrote: >> Hi, >> >> I want to simulate a data set with similar covariance structure as my >> observed data, an

Re: [R] Problem when creating matrix of values based on covariance matrix

2012-08-12 Thread Boel Brynedal
). @Michael - I am simulating a sample size of 20351* 8368 so I do not think that the sample size is the issue here. 2012/8/12 peter dalgaard : > > On Aug 11, 2012, at 16:17 , Boel Brynedal wrote: > >> cov8=cov(sample8,method='spearman') > > There's your problem

Re: [R] Problem when creating matrix of values based on covariance matrix

2012-08-12 Thread Boel Brynedal
A clarification - yes, calculating the pearson covariance does give the expected results. I dont fully understand why yet, but many thanks for this help! 2012/8/12 Boel Brynedal : > Thanks for these replies. > @Peter - are these methods only suitable for pearson covariances? That >