Displaying 20 results from an estimated 200 matches similar to: "2D Convolution Function"
2010 Sep 14
2
How to uncompress a gz file in R
Dear Fellows,
I would like to know how to uncompress a gz file at the R console. I could
not find out any help from the R-help archive.
Thanks for your great help.
Best Regards,
Wonsang You
-----
--
Wonsang You
Special Lab Non-Invasive Brain Imaging
Leibniz Institute for Neurobiology
http://www.ifn-magdeburg.de
--
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2010 Sep 16
2
How to combine matrix and vector
Dear fellows,
I am a novice in R. I would like to combine a matrix and a vector. Assume
that we have the matrix a and the vector b with same length of column.
a<-matrix(seq(1:10),nrow=2,ncol=5,byrow=TRUE)
a=
1 2 3 4 5
6 7 8 9 10
b<-t(c(11,12,13,14,15))
b=
11 12 13 14 15
Then, I want to combine a and b as follows.
c=
1 2 3 4 5
6 7 8 9
2010 Nov 22
3
Fast Two-Dimensional Optimization
Dear R Helpers,
I have attempted "optim" function to solve a two-dimensional optimization
problem. It took around 25 second to complete the procedure.
However, I want to reduce the computation time: less than 7 second. Is there
any optimization function in R which is very rapid?
Best Regards,
Wonsang
-----
Wonsang You
Leibniz Institute for Neurobiology
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2010 Oct 13
2
How to fix error in the package 'rgenoud'
Dear R user fellows,
I would like to ask you about the package 'rgenoud' which is a genetic
optimization tool.
I ran the function 'genoud' with two variables to be minimized by the
following command.
result<-genoud(fn,nvars=2,starting.values=c(0.5,0),
pop.size=1000, max.generations=10, wait.generations=3)
Then, I had the following error message.
Error in
2010 Aug 31
4
How to Adaptively Set Up the Coordinate Range of Multiple Graphs in One Figure
Hi, R-Helpers,
I would like to ask about multiple graphs in one figure. I tried to execute
the following codes.
xlim <- c(1,100)
ylim <- c(1,4)
plot(NA, xlim=xlim, ylim=ylim)
> x <- c(1:100)
for(j in seq(1,10,by=1)) {
y <- j*x^2+log(j)
lines(x, y)
}
In the above codes, I had to arbitrarily set up the coordinate range of the
figure in advance before
2011 Feb 08
1
Simulation of Multivariate Fractional Gaussian Noise and Fractional Brownian Motion
Dear R Helpers,
I have searched for any R package or code for simulating multivariate
fractional Brownian motion (mFBM) or multivariate fractional Gaussian noise
(mFGN) when a covariance matrix are given. Unfortunately, I could not find
such a package or code.
Can you suggest any solution for multivariate FBM and FGN simulation? Thank
you for your help.
Best Regards,
Ryan
-----
Wonsang You
2011 Feb 02
1
Error of 'memory not mapped' in ff Package with VirtualBox
Dear R Helpers,
I would like to report on an error in the ff package here.
The ff package is an R package which enables us to store large data on disk
systematically and have fast access to the database.
I used the package in Linux as a guest OS of VirtualBox, and executed the
following commands.
library(ff)
2009 Mar 31
3
installing RMySQL (PR#13633)
Full_Name: Ankhee Dutta
Version: 2.3
OS: LINUX
Submission from: (NULL) (202.141.12.97)
I have a linux system of Mandriva-2007 with R version 2.3.0 and MySQL with
5.0.0. I have also got DBI-R database interface version-0.1-11 installed on
my Linux system.While installing RMySQL package version 0.5-11 i am facing
problem .
while installation the error report which is coming is as follows:
2005 Feb 15
1
convolution of functions
Dear sir,
we would like to know if there exist any R package containing the
computational performance of the n-fold Stieljes' convolution of functions.
We look forward to hearing from you.
Thank you in advance.
____________________________________
M.Luz G?miz P?rez
Dpt. Estad?stica e Investigaci?n Operativa
Facultad de Ciencias
Universidad de Granada
Telf.: 958-243156
e-mail:
2011 May 18
1
Convolution confusion:
Hi,
I'm new to R, and I'm a bit confused with the "convolve()" function.
If I do:
x<-c(1, 2, 3)
convolve(x, rev(x), TRUE, "open")
= 9 12 10 4 1
But I expected: 3 8 14 8 3 (like in Octave/MATLAB - conv(x, reverse(x)) )
3 2 1 x 1 2 3
= 3 2 1
0 6 4 2
0 0 9 6 3
= 3 8 14 8 3
The thing is, that "convolve(x, x, TRUE, "open")" works.
For me
2010 Jun 04
2
Convolution vector to be derived
I want to generate the following outcome using convolution of two sequences.
x <- c(1,2,3,4,5)
y <- c(6,7,8,9)
The resulting convolution vector is
6
19
40
70
100
94
76
45
When using convolve(), it is hard to produce the result above.
Would you help me out to get that?
Best regards
Moohwan Kim
2005 Sep 29
2
solution of convolution equation
Hello,
May be somebody can help me...
I am trying to find a solution of a convolution equation using fft (and
unfortunately I do not have a good background for this).
So I am just trying to figure out how it can be implemented in R. I have
two multidimensional independent variables X and Z
and I know their densities fx and fz, which are multidimensional arrays.
So I have to find the density of
2005 Dec 23
2
convolution of the double exponential distribution
Is there any R function that computes the convolution of the double
exponential distribution?
If not, is there a good way to integrate ((q+x)^n)*exp(-2x) over x from
0 to Inf for any value of q and for any positive integer n? I need to
perform the integration within a function with q and n as arguments. The
function integrate() is giving me this message:
"evaluation of function gave a
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?
2005 Jun 15
1
Chi square convolution?
Hi,
I want to determine the confidence interval on the sum of two sigma's.
Is there an easy way to do this in R? I guess I have to use some sort of
chisquare convolution algorithm???
Thanx,
Roy
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The information contained in this communication and any atta...{{dropped}}
2013 Mar 14
2
Modifying a data frame based on a vector that contains column numbers
Hello!
# I have a data frame:
mydf<-data.frame(c1=rep(NA,5),c2=rep(NA,5),c3=rep(NA,5))
# I have an index whose length is always the same as nrow(mydf):
myindex<-c(1,2,3,2,1)
# I need c1 to have 1s in rows 1 and 5 (based on the information in myindex)
# I need c2 to have 1s in rows 2 and 4 (also based on myindex)
# I need c3 to have 1 in row 3
# In other words, I am trying to achieve this
2011 Apr 23
1
Arguments to order()
Hi,
The rows of a data frame can be sorted lexicographically as shown in
this example,
my.df <- data.frame(x=c(1,1,1,2,2), y=c(1,2,3,2,1))
my.df[order(my.df$x,my.df$y, decreasing=TRUE), ]
however, I'm wondering if it's possible to pass a variable in as the
first argument to order() so that the actual set of columns used in
the sort can be easily varied?
FWIW, the first argument to
2000 Jan 28
0
convolution bug (PR#408)
Full_Name: Bill Simpson
Version: 65.1 , 0.90.1
OS: Linux
Submission from: (NULL) (193.62.250.209)
I reported this on r-help, but here is official bug report.
The present convolve() does not do convolution by default. Its default behaviour
is
correlation. This is a bug.
The default argument conj should be set to FALSE.
The zero-padding should be on the right for linear convolution (don't
2008 Apr 05
1
bug? nlme 3.1-88 compilation under linx
>From http://bugs.r-project.org/cgi-bin/R:
If you are not sure whether you have observed a bug or not, it is a good
idea to ask on the mailing list R-Help by sending an e-mail to
r-help at stat.math.ethz.ch rather than submitting a bug report.
I'm wondering whether to submit a bug report on this:
==============================================================
>
2019 May 29
3
Making a package CITATION file from BibTeX
Dear Colleagues,
I would like to provide a CITATION file for my package nat.nblast [1].
I have the correct citation in BibTeX format [2]. How can I convert this
BibTeX to the format needed by R for a package CITATION file (I have a
lot of other packages needing citations ...).
I think what I need is the opposite of RefManageR::toBiblatex [3]. This
seems like it should be a common need, so I