similar to: How to express a tree?

Displaying 20 results from an estimated 6000 matches similar to: "How to express a tree?"

2008 Nov 23
2
How is R working in multicore and multiprocessor environment?
My Dear R buddies, I'm feeling ashamed that I've been running my R program on some servers for a while but do not know exactly how R is working. The servers are chained together using Sun Grid Engine. Each node has 8 quad-core CPUs. I wonder how many cores and CPUs are used by a simple single-thread R program. Thanks a lot. Best wishes, -- ??? Hesen Peng
2009 Jul 11
1
Conditional expand.grid()
Hello my R buddies, I'm trying to generate a bivariate data.frame with the elements of first row greater than the second row. The more complicated method that I can think of is: n <- 10 temp <- expand.grid(1:n,1:n) temp<-temp[temp[,1]>temp[,2],] However, I guess there must be some easier way of doing this. Besides, if inequality condition is applied at the very
2008 Nov 29
2
Reading mixed tables
Dear R buddies, This weekend I became interested in solving Google Code Jam problems using R. I guess R may work very well in this kind of contests but the input of file has been a problem for me. Take this case for example (http://code.google.com/codejam/contest/dashboard?c=agdjb2RlamFtchALEghjb250ZXN0cxjRzBQM), the files are usually of the form: A(number of lines for group 1) a11 a12 a13 a21
2008 Aug 12
2
Multiple column/row names?
Hi all, I wonder if there is a way to create a matrix with two (or even more) column/row names? Thank you very much. Have a nice day. -- ??? Hesen Peng http://hesen.peng.googlepages.com/
2008 Sep 11
1
Convex optimization in R?
Hi my R buddies, I'm trying to solve a specific group of convex optimization in R. The admissible region is the inside and surface of a multi-dimensional eclipse area and the goal function is the sum of absolution values of the variables. Could any one please tell me whether there's a package in R to do this? Thank you very much, Best wishes, -- ??? Hesen Peng
2008 Oct 03
1
When to set small values to 0?
My dear R buddies, I've run into a problem when doing numerical computation recently. In a program that I've been working on, I usually get a vector of real values which are theoretically (and it's correct) supposed to decrease until reaching zero after a given value. However, most of the value just wander at 10^-8 scale and never shrink exactly to zero. So I guess I should manually
2008 May 18
2
*apply function for arrays?
Hi all, I've recently been writing functions which may deal with very large arrays. And I hope to use *apply functions in the program so that the code may look nicer and the performance may be better in the following two situations. The first situation is: I'm having an array A with dim(A)==c(m,n,p). And I want to apply a function F to a group of elements in A like: 1) F is applied to
2008 Nov 24
2
More than doubling performance with snow
Hey my R buddies, I installed the "snow" and "rpvm" package on my Lenovo Thinkpad T400 today. The experiment below gave me a surprise. The time consumed by serial processing was several times larger than that taken by parallel processing. I'm very curious how this happened. Thank you very much. > library(snow) > > cc <- makePVMcluster(2) > > temp <-
2008 Oct 08
5
ParallelR
Anyone using or has access to ParallelR? I was looking at the page and found nothing really useful! http://www.revolution-computing.com/sitegenius/topic.php?id=195 I want to see if I can run R on a cluster of workstation, and use batch systems like Grid Engine or Xgrid: http://gridengine.sunsource.net/ http://ww.apple.com/acg/xgrid/ --Chi
2008 Jul 01
1
extracting elements from a list in vectorized form
Hi; It seems to me that has probably been asked in the past. But I cannot find the track. I usually need to extract elements from a list and contruct vector from them; e.g., to create a table. Perhaps there is a way to directly extract them without looping? Simple example: > S.lst $sublist.1 $sublist.1$age [1] 24.58719 $sublist.1$weight [1] 60.82861 $sublist.2 $sublist.2$age [1] 32.39551
2009 Aug 06
5
Is there a 'vi' mode in R?
Hi, I'm wondering if R provide a vi mode in the command line just like other shells such as bash do. Can somebody let me know? Regards, Peng
2010 Sep 22
2
efficient list indexing
Hello everyone, I need some help with lists inside lists (a good way to emulate a struct)\ Assume that there is a small list called fred: fred <- list(happy = 1:10, name = "squash") and a big list called bigfred that includes fred list 5 times bigfred <- rep(fred,5) Is it possible somehow to index all these sublists(fred) inside bigfred with a more direct way like this:
2007 Feb 22
3
List filtration
Hello R-ologists, Imagine you have a list "list" like so: >list [[1]] [1] "IPI00776145.1" "IPI00776187.1" [[2]] [1] "Something" "IPI00807764.1" "IPI00807887.1" [[3]] [1] "IPI00807764.1" [[4]] [1] "Somethingelse" What I need to achieve is a filtered list "list2" like so: >list2 [[1]] [1]
2008 Nov 04
2
strange list structure question
my problem is more complex than below but I think below can suffice. i have a list and the name of it at the top level is GGG. so, if i do an lapply and operate on lower components in the sublist, then I can do as shown in EXAMPLE 1 and what will come back will be named GGG at the top level. but, suppose that , the function inside the lapply function was more complex and i wanted to
2011 Aug 04
2
How to extract sublist from a list?
Hi everyone, Suppose I have a list named "lst", see below: > lst $sub1 ... $sub1$x ... $sub1$y .... $sub2 ... $sub2$x ... $sub2$y ? $sub3 ... ... ... Now, I want to extract the sub-sublist $y from every sublist(sub1, sub2...) and then storage them to a new list. I know how to extract them by subscript or list name one by one, but I wonder if there exist some tricks to finish this
2009 Jun 16
1
Constrained Optimization, a full example
After a few days of work, I think I nearly have it. Unfortunately, theta is unchanged after I run this (as a script from a file). I thought that theta would contain the fitted parameters. The goal here is to find the least squares fit according to the function defined as "rss" subject to the constraints defined as ui and ci. I defined ui and ci to (hopefully) force par2 and par3
2012 Dec 22
1
plotting and saving diagrams automatically
[if the format of my email is changed or is difficult to understand, a text file is attached for easy understanding]Dear useRs, i was wondering that if its possible in R to automatically generate plots and get it saved at the desired location? i have data of cancer patients, from about 1000 cities around the world. i have converted that data into a list (called tcp) and that list has 1000
2010 Jan 05
1
variable three dimensional array
I am using R for my bioinformatics research. I am dealing with a graph in which I need to find all possible path. I was looking for some package that solve my purpose but all in vain. There are available algorithms but most of them find shortest path that ignore other paths So I decided to write my own from scratch. I need to create a two dimensional matrix of size nXn. The element of each entry
2006 Jul 02
4
:order in partial
Hi, i was looking through the docs and couldn''t find a good clean solution for ordering a partial with an :order clause. say i was iterating over categories and thier corresponding sub-categories (regular belongs to) and wanted to order the subcategories according to a certain column; <% for category in @categories %> <% render: partial => ''sublist'',
2011 Oct 14
3
Split a list
I have a list of dataframes i.e. each list element is a dataframe with three columns and differing number of rows. The third column takes on only two values. I wish to split the list into two sublists based on the value of the third column of the list element.  Second issue with lists as well. I would like to reduce each of the sublist based on the range of the second column, i.e. if the range of