similar to: Inverting matrix...

Displaying 20 results from an estimated 4000 matches similar to: "Inverting matrix..."

2000 Jan 14
2
Matrix output from drawing functions
Dear all, I'm a bit confused about the output from functions that generates random values, e.g. rpois. I'm using 0.65.1 on Digital UNIX alphaev6. If I say > rpois(10,5) output is not unexpectedly: [1] 4 6 5 7 6 5 2 2 5 3 but I figured that if I go: > rpois(10,1:10) I would get a 10x10 matrix as output, with random values for each of the vector elements in the row vectors, but
2001 Nov 16
1
$name vs. [["name"]]
Dear all, I have been away for a month, but some time ago, I noted something that was very surprising to me. I think this example illustrates it well: > test <- data.frame(col1 = c(1,2), col2=c(3, 4)) > test col1 col2 1 1 3 2 2 4 > apply(test, 1, function(x) browser()) Called from: FUN(newX[, i], ...) Browse[1]> x$col1 NULL Browse[1]> x[["col1"]] [1] 1
2001 Aug 02
1
Package GSS for interpolation in more than 2D?
Dear all, There has been some time since I asked about interpolation in higher (>2) dimensions, and I must admit I failed to write a function to do this myself the last time, but eventually ended up doing it in MATLAB. I tried to translate the MATLAB code, but MATLAB code is so much more opaque than R (S) code, so I failed that too, mainly because I could only get one MATLAB session, I would
2000 Jun 24
1
Garbage Collecting
Dear all, Me and the Garbage Collector doesn't understand each other... I'm on R-1.0.1 (I have requested an upgrade to the right local people), an osf1 system with an alphaev6 CPU. I have fair amounts of memory to use, but it seems to be used up pretty fast nevertheless. I'm now trying to see what the garbage collector does, I have inserted a gc(v=T) call at a spot in my code. I
2001 Jun 04
1
2D convolution
Dear all, I have an image that I need to filter, and so I'm looking for a method to convolve it with a matrix. If I understood the docs for convolve correctly, it only works in 1D (and I have tried to convolve, it didn't look good). So, I wondered if anybody have implemented 2D convolution in R, or have any good advices to share (beyond having a look at mvfft), before I go hacking?
2000 Feb 13
1
Underflow warnings?
Dear all, I'm a bit concerned about underflow problems. Such problems typically occur when two almost equal numbers are subtracted. I was wondering if R has any mechanisms for warning users about potential problems, or if any policy has been developed? To check, I just did: > 1.0000000000000001 - 1 [1] 0 > 1.000000000000001 - 1 [1] 1.110223e-15 > 1.00000000000001 - 1 [1]
2001 Apr 30
1
Some loglog density plot
Dear all, A looong time ago, Witold Eryk Wolski asked here why there wasn't a log="xy" parameter to the hist() function <URL:http://www.R-project.org/nocvs/mail/r-help/2001/0267.html>, and Prof. Ripley responded that a loglog histogram does not make much sense, and that one should use a better density estimate if one seeks to plot log density. I understand the point and I
2001 Aug 08
1
Strategy for creating a palette...?
Dear all, I'm generally not a big fan of GUIs, but I have just discovered one thing where a GUI would be a nice thing: creating color palettes. I'm creating an "image", for transparencies for a lecture I'm giving, so this is going to look great... :-) What I'm out for, is to make green tones and red tones, and a relatively sharp break between them. This break will
2000 Nov 08
1
Re: [R] Strange means of numbers drawn from rpois (PR#730)
On 8 Nov 2000, Peter Dalgaard BSA wrote: >Done... Great! >(This kind of behaviour has been observed on various platforms and >various compilers, sometimes getting stuck around 15.15 and sometimes >around 14.5. Others report no problems. Very strange. I've seen one >case where it apparently shifted from one regime to the other.) Yes, it does that here too.... The following is
2001 Feb 15
2
Reading single precision floats from binary file
Dear all, I have a few files with binary data written by a C program a friend wrote. I allready have program to read these files, Thomas Lumley and Prof Brian D Ripley was kind enough to respond to a question to this list earlier with some code that works perfectly, so this is really no problem, it is more out curiousity. Most of my files consists of 40000 single precision floats, and I figured
2000 Nov 08
3
Strange means of numbers drawn from rpois
Dear all, I think I must be going crazy.... If I do > mean(rpois(1000000, 14)) I get: [1] 13.50420 and again: > mean(rpois(1000000, 14)) [1] 13.49896 > mean(rpois(1000000, 14)) [1] 13.50161 > mean(rpois(1000000, 15)) [1] 14.49250 > mean(rpois(1000000, 15)) [1] 14.49897 > mean(rpois(1000000, 14.5)) [1] 13.99689 > mean(rpois(1000000, 14.5)) [1] 13.9963 This was on a platform
2000 Jul 27
1
Interpolation using a piecewise linear function in higher dimensions
Dear all, I am just wondering if anybody has implemented a function that can give a piecewise linear interpolation in more than 2 dimensions? I have looked at the akima package, but I would rather like a piecewise linear interpolation rather than a spline and while it did the job quite satisfactory for 2 dimensions, I need to interpolate in at least three dimensions. If anybody has implemented
2000 Apr 26
1
Writing lgrindefs
Dear all, I'm writing a lgrind definition for R. Lgrind is a program to produce pretty program listings for inclusion in LaTeX documents. Does anybody here have any experience with lgrindefs? My definition now looks like this: R:\ :pb=^\d?\p\d<-\dfunction\(\a\):\ :bb={:be=}:cb=\d#:ce=$sb=":se=\e":lb=':le=\e':id=.:\ :zb=@:ze=@:tb=%%:te=%%:mb=%\$:me=\$%:vb=%\|:ve=\|%:\
2000 Apr 26
1
Writing lgrindefs
Dear all, I'm writing a lgrind definition for R. Lgrind is a program to produce pretty program listings for inclusion in LaTeX documents. Does anybody here have any experience with lgrindefs? My definition now looks like this: R:\ :pb=^\d?\p\d<-\dfunction\(\a\):\ :bb={:be=}:cb=\d#:ce=$sb=":se=\e":lb=':le=\e':id=.:\ :zb=@:ze=@:tb=%%:te=%%:mb=%\$:me=\$%:vb=%\|:ve=\|%:\
2000 May 12
1
Geometric Distribution at prob=c(0,1)
Dear all, I''m working with the geometric distribution for the time being, and I''m confused. This may have more to do with statistics than R itself, but since I''m getting results from R I find counterintuitive (well, yeah, my statistical intuition has not been properly sharpened), I feel like asking. The point first: If I do > rgeom(1,prob=1) I get: [1] NaN Warning
2000 May 25
4
Needed: Understading runif() output :-)
Dear all, I have been trying to understand what runif() is telling me. I am generating lots of numbers (billions and billions (wow, I''ve dreamed about saying that for many years... :-) ), for a distribution that has the following quantile function: 1 / (2 * sqrt(1 - p)) (that is, the distribution has a lower cutoff) As you can imagine, this has rather heavy upper tail. I was
2000 Feb 29
2
Reading data from file made by C fwrite
Hello! First, I must also congratulate the R core team with their accomplishment! I have gotten to like R a lot, and I have recommended it for inclusion in an "Astronomy for Linux"-distribution which is in use by many professional astronomers and observatories. I'm currently working on importing data from files created by a C program (that I have not written myself, I have the
2000 Jul 09
1
Modified Histogram functions
Dear all, I have done further modifications on the histogram functions that I reported earlier this year, and I hope this can be of use and perhaps included in the distribution. I have been using this stuff a couple of months myself, and while it is nothing sophisticated, it has it's applications. :-) I did a few small modifications today to make it a bit more compact. I have modified the
2000 Mar 23
1
Some "new" stuff for hist.R
This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. Send mail to mime@docserver.cac.washington.edu for more info. --0-201145637-953833073=:7710 Content-Type: TEXT/PLAIN; charset=US-ASCII Dear all, I've been hacking on histograms the past couple of days. I wanted to do two things, add
1999 Dec 01
0
Applying a function of several variables to data
Dear all, After looking at several packages I decided I would use R for my thesis work (we've even got a site license for S-plus), so I'm learning. I have run into a problem, and nobody on the house has a solution, so I'm wondering if anybody out there can help. I've got two functions of four variables, one outputs a scalar, the other an array, and I want to be able to give an