search for: lanczos

Displaying 15 results from an estimated 15 matches for "lanczos".

2009 Oct 09
2
different time series in one plot
Hello, I need to put 2 or more different time series to one plot for comparison each other. The problem is that the time series are irregular, moreover the time lenghts and periods are not the same. Is there a way to manage it in R? Many thanks for any hint and advice in advance Tomas
2009 Oct 26
2
basic statistics to csv
I know that my question is like a very newbie question, but at the moment I stacked with it and I need a quick solution. I need to make an overall statistical overview of various datasets, the summary() and numSummary() functions are fully sufficient. My question is, how can I export results to a spreadsheet-like file, as a .csv. For the summary() with an "x" dataset I can use this way:
2008 Aug 06
2
Statistics on raster pictures - asking for an advice
Hello, I need to do some basic statistics on raster images (tiff or png). I need only an advice where to start, which package is the most appropriate. My search attempts were without success, yet. Many thanks Tomas
2007 Feb 06
1
Attachment_fu ImageScience FreeImage thumbnail quality
I''ve tried migrating acts_as_attachment to attachment_fu (just to see if I could replace RMagick with ImageScience+FreeImage), but the quality of the thumbnails is just horrendous, blurred beyond recognition (downscaling a 1280x1024 to a few considerably smaller thumbnails). Changing attachment_fu to use RMagick again and the thumbnails were crispy sharp again. I was wondering
2008 Jun 18
2
highest eigenvalues of a matrix
DeaR list, I happily use eigen() to compute the eigenvalues and eigenvectors of a fairly large matrix (200x200, say), but it seems over-killed as its rank is limited to typically 2 or 3. I sort of remember being taught that numerical techniques can find iteratively decreasing eigenvalues and corresponding orthogonal eigenvectors, which would provide a nice alternative (once I have the
2009 Sep 13
2
zoo plot: yearly marks on X-Axis
On Sun, 2009-07-26 at 13:17 +0200, Poersching wrote: > stvienna wiener schrieb: > > Hi all, > > > > I am plotting a financial time series, but I need a more detailed X-Axis. > > > > Example: > > x <- zoo(rnorm(1:6000), as.Date("1992-11-11")+c(1:6000)) > > plot(x) > > > > The X-Axis is labeled "1995", "2000"
2004 Apr 19
0
R analog of Matlab "eigs" function
...cription here: http://www.mathworks.com/access/helpdesk/help/techdoc/ref/eigs.html). This function differs from the standard "eigen" in that it computes a *few* eigenvectors for cases in which your matrix is very large and/or you don't need all the eigenvectors. (It uses the Arnoldi-Lanczos iterative method, as implemented in C in ARPACK). For example, this is the case for classical multidimensional scaling when you only need the first 2 eigenvectors. I feel almost certain that something like this is probably somewhere in R, possibly even as a (hidden) subroutine within a function l...
2008 Aug 08
1
problem to load the RGrace package
When I am loading the RGrace package I am getting the following errormessage: Loading required package: RGtk2 Loading required package: grid Loading required package: cairoDevice Error in figure() : could not find function "gladeXMLNew" Error : .onLoad failed in 'loadNamespace' for 'RGrace' Error: package/namespace load failed for 'RGrace' I am running R 2.7.1
2011 Nov 18
0
how to define the bound between parameters in nls() (Jinsong Zhao)
The multiple exponential problem you are attempting has a well-known and long history. Lanczos 1956 book showed that changing the 4th decimal in a data set changes the parameters hugely. Nevertheless, if you just need a "fit" and not reliable paramters, you could reparameterize to k1 and k2diff=k2-k1, so k2=k1+kdiff. Then kdiff has a lower bound of 0, though putting 0 will almost...
2000 Nov 09
1
Alternative to Numerical Recipes
Some time ago I mentioned the online version of the book "Numerical Recipes in C" http://www.ulib.org/webRoot/Books/Numerical_Recipes/ and inadvertantly stirred up a hornets' nest. I obtained from this book code to calculate the Incomplete beta function. It appears in: 6.4 Incomplete Beta Function, Student?s Distribution, F-Distribution, Cumulative Binomial Distribution, p.226, and
2009 Jul 25
1
yaxp problem for more irregular time series in one plot
Good day, I'm trying to get more time series in one plot. As there are bigger differences in values of variables I need logaritmic y axis. The code I use is the following: nvz_3_data <- read.csv('/home/tomas/R_outputs/nvz_3.csv') date <- (nvz_3_data$date) NO3 <- (nvz_3_data$NO3) NH4 <- (nvz_3_data$NH4) date_p <- as.POSIXct(date, "CET") par(mfrow=c(2,1), ylog
2008 Oct 03
1
3D scatter, groups, RdbiPgSQL...
hello, I wish to create some 3d scatter diagrams visualising different grouped data set by a given field in the database. I tried the scatterplot3d package, as well as the plot3d and scatter3d functions (both within the rgl resp. Rcmdr package). My first question is, whether is it possibe to group data in the scatterplot3d and plot3d, because I did not succeed to use the groups = ...
2009 Sep 11
1
format (?) problems with data imported from postgres
Good day, I read some data from a PostgreSQL database by a following script: library(Rdbi) library(RdbiPgSQL) # conn becomes an object which contains the DB connection: conn <- dbConnect(PgSQL(), host="localhost", dbname="BVS", user="postgres", password = "*******") query_duj_kal <- dbSendQuery(conn, "select zdroj as well, cas as date, fe2,
2012 Nov 22
1
problems with RPostgreSQL compilation
Hello, I am trying to install RPostgreSQL, but without success at the moment, getting an errormessage - see below. My OS is Fedora 17, R version 2.15.2, PostgreSQL 9.2.1 with Postgis 2.0.1 spatial extension. Thank You for any help, advice or hint in advance. Regards Tomas > install.packages("RPostgreSQL", dependencies=TRUE) trying URL
2008 Jul 08
0
Change legend in the 'hydrogeo' package
At first sorry for the possibly dumb question of a newbie. I am using the hydrogeo package to visualize approx. 300 data within the Piper-Hill diagrams. The package is using a dataframe with 6 columns, first of them is containing the row.names, next four with the data itself. The last column contains "WaterTypes" dividing data to several categories. The diagram is created by the