I want to compute a diffusion kernel, which involves taking exp(b*A) where A is a large matrix. In order to play with values of b, I'd like to diagonalize A (so that exp(A) runs quickly).
My matrix is about 25k x 25k, but is very sparse - only about 60k values are non-zero. Matlab's "eigs" function runs of out memory, as does octave's ...
How do you solve the dependencies of packages within your functions? I add require(package) into the function, but I wonder if there's a preferred way of accomplishing this task.
...
I've got a data frame with far too many rows to be able to do a spatial correlogram. Instead, I want to grab 40 rows for each species and run my correlogram on that subset.
I wrote a function to subset a data frame as follows:
samp <- function(dataf)
{
dataf[sample(1:dim(dataf)[1], size=40, replace=FALSE),]
}
Now I want to ap...
stock.ba is a ts object of monthly stock returns and I would like to fit an eGARCH model, but I keep getting this error using a new download of rgarch in R 2.10.1:
> stock.ba.egarch <- ugarchfit(stock.ba, spec)
Error in UseMethod("ugarchfit") :
no applicable method for 'ugarchfit' applied to an object of class "ts"
Here's the (rele...
Hi,
Assuming in R, I have a data.frame with the first column representing the time (as POSIXct). The rest of the columns (e.g., columns 2) are numeric data.
I would like to group time into 3-minute intervals. Each interval will the the average of values that falls into that particular interval.
Right now, I have a for-loop that iterat...
Sometimes R stops displaying output. I type the number 1, followed by the return key, and nothing appears.
This situation occurred after I pressed the "STOP" icon in the window, which is for stopping long calculations. I'm using R 2.11.0 on a Mac.
Does pressing "STOP" cause R to stop displaying output? How do I get R to display output ...
ESS allows us to indent a line and an expression. Is there a key binding for indenting a buffer? If not, can we create it?
...
Background
I have climate data (temperature, precipitation, snow depth) for all of Canada between 1900 and 2009. I have written a basic website and the simplest page allows users to choose category and city. They then get back a very simple report (without the parameters and calculations section):
The primary purpose of the web appli...
Sorry for this novice question: if I fit a lm() model or loess() model, and save the model somewhere in a file or in database, for later using by third party with predict() method, do I have to save the entire model object? Since returned model object contains orginal raw data, this returned object can be huge.
...
for working with financial time series, like daily stock prices or intraday data, which time series packages are preferred? xts, plain zoo, or timeSeries or something else?
I use both xts and zoo, but sometimes not sure to use xts exclusively or sometimes zoo have advantage of lighter overhead; also, I remembered a review paper on all th...
I am having difficulty with:
Listing the R packages and functions available to PostgreSQL.
Installing a package (such as Kendall) for use with PL/R
Calling an R function within PostgreSQL
Listing Available R Packages
Q.1. How do you find out what R modules have been loaded?
SELECT * FROM r_typenames();
That shows the types that a...
I've been using var.test and bartlett.test to check basic ANOVA assumptions, among others, homoscedascity (homogeniety, equality of variances). Procedure is quite simple for One-Way ANOVA:
bartlett.test(x ~ g) # where x is numeric, and g is a factor
var.test(x ~ g)
But, for 2x2 tables, i.e. Two-Way ANOVA's, I want to do something lik...
I'm trying to use recode in R (from the car package) and it is not working. I read in data from a .csv file into a data frame called results. Then, I replace the values in the column Built_year, according to the following logic.
recode(results$Built_year, "2 ='1950s';3='1960s';4='1970s';5='1980s';6='1990s';7='2000 or later'")
When I c...
Hi, I have large amounts of data (a few terabytes) and accumulating... They are contained in many tab-delimited flat text files (each about 30MB). Most of the task involves reading the data and aggregating (summing/averaging + additional transformations) over observations/rows based on a series of predicate statements, and then saving th...
I'm using GNU/Linux distro (Arch, if that's relevant), Emacs v23.2.1, ESS v5.9 and AucTeX v11.86.
I want to setup AucTeX to recognize .Rnw files, so I can run LaTeX on .Rnw files with C-c C-c and get .dvi file automatically. I reckon it's quite manageable by editing .emacs file, but I still haven't got a firm grasp on Elisp.
Yet anoth...
In R, if we set the help_type argument of help() function to 'html' and call it, it will automatically open the html help in a browser. However, this is not the case for help_type = 'pdf'. Only the pdf is generated. How can I make it automatically after the help file is generated? I believe that pdf help are preferred by some as it can d...
Is it possible to pass just a variable name in a function call and have it utilised as such within the function??
pseudocode:
q<-function(A){
b<-(w%in%A.2|w%in%A.7)
factor(b,levels=c(F,T),labels=c("non-"A,A))}
w<-c(0:10)
e.2<-c(1,2)
e.7<-c(6,7)
what I´d like to do is
q(e)
and have returned
non-e,e,e,non-e,non-e,e,e,...
I'm trying to understand how to have more than one series on a plot, using the following data.
Year <- c('1950', '1960', '1970', '1980')
Bus <- c(10,20,30,40)
Bus.sd <- c(1.1, 2.2, 3.3, 4.4)
Car <- c(20, 20, 40, 40)
Car.sd <- c(1.1, 2.2, 3.3, 4.4)
sample_data = data.frame(Year, Bus, Bus.sd, Car, Car.sd)
qplot(Year, Bus, data=sample_da...
I'm trying to make a graph of a table and graph it in log space.
First of all, plot(dat) gives me the grid of graphs
Second of all, plot(dat, log="xy") gives me the correct plots of data in log space
However, plot(dat, log="xy") ruins the main diagonal's labels of names(dat)
R version 2.11.0
Sample Data:
cold cold_contro...
Hi,
I have a vector of strings. Check out my vector, it's awesome:
> awesome
[1] "a" "b" "c" "d" "d" "e" "f" "f"
I'd like to make a new vector that is the same length as awesome but where, if necessary, the strings have been uniqueified. For example, a valid output of my desired function would be
> awesome.uniqueified
[1] "a" "b" "c...