Displaying 20 results from an estimated 1000 matches similar to: "Combinatorial problem"
2011 Sep 29
1
plot.igraph
I am having trouble plotting one of my graphs (think graph theory graph with
edges and vertices, not scatterplots or histograms). For some pairs of
vertices, I want multiple edges to be visible in my graph. As an example of
this, in my script below, I want two edges to be visible from vertex 1 and
vertex 9 (among some others) yet when I plot it, only one edge is visible.
1999 Dec 02
1
Error in plot.aov() (PR#356)
# Your mailer is set to "none" (default on Windows),
# hence we cannot send the bug report directly from R.
# Please copy the bug report (after finishing it) to
# your favorite email program and send it to
#
# r-bugs@biostat.ku.dk
#
######################################################
The error occurs following the third Hit <Return> below:
> y_rnorm(40)
>
2005 Sep 30
4
by() processing on a dataframe
I want to calculate a statistic on a number of subgroups of a dataframe,
then put the results into a dataframe. (What SAS PROC MEANS does, I
think, though it's been years since I used it.)
This is possible using by(), but it seems cumbersome and fragile. Is
there a more straightforward way than this?
Here's a simple example showing my current strategy:
> dataset <-
2009 Jan 26
7
Wine and Guitar Pro 5.2
Ubuntu 8.10 Desktop, Wine 1.1.13 (upgraded from 1.0.1 to try to solve my problem). I have used used Guitar Pro very recently without a problem. After a PSU failure, I had to reinstall the OS and downloaded and installed software, including Wine. Guitar Pro appeared to install properly and its splash screen was normal. Immediately the full program ran, a fatal error stopped it. I have a screen
2010 Aug 21
1
lattice::xyplot() with one factor for points and another for lines
Hi:
In lattice, how does one handle separate graphical behavior for two
different factors? In the xyplot below, the objective is to use the levels
of one factor to distinguish corresponding shapes and colors, and the levels
of the other factor to perform level-wise loess smooths.
# Illustrative data:
d <- data.frame(time = rep(1:8, each = 6), val = rnorm(48),
gp1 =
2004 Apr 01
2
row selection based on median in data frame
Hi. I am having trouble thinking of an easy way to grab rows out of a
data frame. I want to select the rows with a median value when the
rows are similar.
A simple example is this table, which I could read into a data frame.
I would like to find a new data frame with only the rows with a median
value for the "c" column given a certain "a" value.
For example, the c values
2008 Oct 17
3
Guitar Pro in Wine?
My uncle recently bought a new computer and he wants me to help him install Guitar Pro.
The thing is, he doesn't have Windows, and I'm thinking of installing Ubuntu with wine on the comp.
Quiz time!
Can you use wine, with GP, and if you can, deos it perform poorly in any ways?
2006 May 26
2
combinatorial programming problem
Hola!
I am programming a class (S3) "symarray" for
storing the results of functions symmetric in its
k arguments. Intended use is for association indices
for more than two variables, for instance coresistivity
against antibiotics.
There is one programming problem I haven't solved, making an inverse
of the index function indx() --- se code below. It could for instance
return the
1999 Dec 03
0
Error in plot.aov() (PR#356) (fwd)
Confirmation from John Maindonald.
--
Brian D. Ripley, ripley@stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272860 (secr)
Oxford OX1 3TG, UK Fax: +44 1865 272595
---------- Forwarded message ----------
Date: Fri, 3
2010 Jun 24
1
[OT] Combinatorials wtih constraints
This is not an R question, but a question on some combinatorial mathematics. Apologies for the OT if it is wildy inappropriate. The traditional C(n.k) method tells me how many combinations k I can make with n objects. However, suppose I want the number of combinations where an object cannot be used more than Q times where Q is a parameter that changes?
For instance:
combn(LETTERS[1:5], 3)
shows
2003 Dec 17
1
repeated measures aov problem
Hi all,
I have a strange problem and rigth now I can't figure out a
solution.
Trying to calculate an ANOVA with one between subject factor (group)
and one within (hemisphere). My dependent variable is source
localization (data). My N = 25.
My data.frame looks like this:
> ML.dist.stack
subj group hemisphere data
1 1 tin left 0.7460840
2 2 tin left
2003 Feb 04
5
SORTING Arrays by index value
Hello, I'm somewhat new to R. I've searched the archive for the last year
and tried to consult the manual pages for the following problem, but did
not find an answer.
I want to sort an array by the index values. Here is the array
>acc.gp.bl.wtmn
Gp17 Gp4
1 0.5703125 0.6406250
10 0.7812500 0.7109375
11 0.8046875 0.7343750
12 0.8359375 0.7890625
13 0.8515625 0.7109375
2011 Jan 24
2
Help with expression
I have a problem with expressions. I am trying to create a title where
the parameter of interest is displayed as a Greek character. Which
parameter is being considered is stored in a character variable.
As an example, if I have
param <- "alpha"
and then do
plot(0, 0, main = bquote(Parameter==.(param)))
then in the title I get "Parameter = alpha",
whereas I want the
2010 Aug 22
0
lattice::xyplot() with one factor for points and another for lines - solution
Hi:
Yesterday, I posted a question regarding how to handle different graphical
behavior between two factors in xyplot() [package lattice]. After a public
and private reply from Deepayan Sarkar, the problem has been resolved
nicely, including the addition of a stacked legend for the two factors in
question. The latter requires package latticeExtra.
library(lattice)
library(latticeExtra)
# Test
2010 Sep 09
6
Reproducible research
I am investigating some approaches to reproducible research. I need in
the end to produce .html or .doc or .docx. I have used hwriter in the
past but have had some problems with verbatim output from R. Tables are
also not particularly convenient.
I am interested in R2HTML and R2wd in particular, and possibly odfWeave.
Does anyone have sample documents using any of these approaches which
2013 Nov 16
1
[LLVMdev] Publication: Combinatorial Preallocation Scheduling
Preallocation Instruction Scheduling with Register Pressure Minimization Using a Combinatorial Optimization Approach
G. Shobaki, M. Shawabkeh and N. Abu-Rmaileh
ACM Transactions on Architecture and Code Optimization (TACO). vol. 10, issue 3, Article 14 (Sept. 2013)
http://dx.doi.org/10.1145/2512432
Regards
Ghassan Shobaki, PH.D
Assistant Professor
Department of Computer Science
Princess Sumaya
2009 Aug 11
1
Help on a combinatorial task (lists?)
Hello!
I have the following combinatorial problem.
Consider the cumulative sums of all permutations of a given weight vector
'w'. I need to know how often weight in a certain position brings the
cumulative sums equal or above the given threshold 'q'. In other words,
how often each weight is decisive in raising the cumulative sum above 'q'?
Here is what I do:
w <-
2012 Jul 17
1
Need Help in a Combinatorial Optimzation Problem
Dear Community,
I have a problem I am trying to code in R.
Suppose there are 7 products and each have a ROI value attached to it.
There are 400 representatives who calls 150,000 customers with these
product detailing and achieve sales through the calls.
There is a cost per call and revenue earned from the call.
Constraint is revenue should be greater than the cost.
Now there can be at most 7
2011 Dec 16
1
optim with simulated annealing SANN for combinatorial optimization
Hi all
I am trying to solve a combinatorial optimization problem. Basically, I can
reduce my problem into the next problem:
1.- Given a NxN grid of points, with some values in each cell
2.- Find the combination of K points on the grid such that, the maximum
mean value is obtained
I took the Travel SalesMan problem example in ?optim documentation. I am
not sure if I have understood correctly
2010 Apr 29
1
randomness in stepclass (klaR) or lda (MASS) ?
Hi,
a colleague ran a stepwise discriminant analysis
twice in a row and got different results, suggesting
some "sochasticity" in the algorithms involved.
I looked at her data and found that there was a lot
of collinearity, so that I reckoned that maybe "stepclass"
(klaR) cannot find a clear winner when trying to include a
new variable and makes a random choice. Is that true?