Displaying 20 results from an estimated 1000 matches similar to: "How to avoid a for-loop?"
2012 Feb 29
2
How are the coefficients for the ur.ers, type DF-GLS calculated?
I need some real help on this, really stuck
how are the coefficients for
ur.ers(y, type = c("DF-GLS", "P-test"), model = c("constant", "trend"),
lag.max = 0)
The max lag is set at zero, so the regression should simply be
Diff(zt) = a*z(t-1)
where a is the value i'm trying to find and z(t)'s are the detrended values.
but through performing
2004 Jun 11
1
lattice: cumsum and xyplot
I want to display cumulative summary functions with lattice.
First I tried to get cumulated data:
library(lattice)
data(barley)
d.cum <- with( barley, by( yield, INDICES=list(site=site,year=year), FUN=cumsum ) )
I got a list of vectors.
I tried to get a dataframe which I could use in xyplot.
But neither of the following functions led to the goal:
d.cum.df1 <-
2009 Jan 21
1
Multifractal detrended fluctuation analysis
Dear R-users,
Has anyone written a function for multifractal detrended
fluctuation analysis? The "fractal" package does mono-fractal DFA,
but not multifractal as far as I can tell. The MF-DFA approach is
presented in:
J. W. Kantelhardt, S. Zschiegner, E. Koscielny-Bunde, S. Havlin, A.
Bunde, and H. E. Stanley, "Multifractal Detrended Fluctuation
Analysis of
2011 Sep 01
2
R Help finding Mean
bob<-read.csv('shi.csv', header=T)
newmean<-matrix(0, test, dim(bob)[2]-6);a<-0; for (i in
c(4,8:(dim(bob)[2])))
{a<-a+1;newmean[,a]<-tapply(bob[,i], bob$Exam, mean)}
colnames(newmean)<-colnames(bob)[c(4,8:(dim(bob)[2]))]
Could anyone please help me what does the above code does ... I want to find
mean ... but would like to know what exactly is the above code doing.
2011 Jul 23
2
sum part of a vector
Dear colleagues, I have a data set that looks roughly like this;
mydat<-data.frame(state=c(rep("Alabama", 5), rep("Delaware", 5), rep("California", 5)), news=runif(15, min=0, max=8), cum.news=rep(0, 15))
For each state, I'd like to cumulatively sum the value of "news" and make that put that value in cum.news.
I'm trying as follows but I get
2007 Oct 26
5
help
hello,
please can anyone help me out. Am a new user of R
program. Am having problem
with this code below, not getting the expected
results.
1. Each m, the cumulative sum should be 1.000 but the
2nd and 3rd m returned 2.000 and 3.000
instead of 1.000.
2. to get the LCL(m) and UCL(m) for each m base on
these instructions
if out.cum > 0.025 then LCL(m)= y-1
if out.cum >0.975
2008 Apr 18
2
Correspondence and detrended correspondence analysis
Hi,
I hope someone knows the answer to this or has a real good reference about it (I am using Legendre & Legendre, Numerical Ecology, 1998).... My data is a data.frame with locations as rows and vegetation assemblages / species as columns. I've done a PCA, a correspondance analysis (CA) using ca in ca package and a detrended correspondance analysis (DCA) using decorana from vegan package.
2003 Jan 29
2
Curve Fitting Question - Newbie
Hello, I have what should be an easy question. I'm a
new r user and making the transition from menus to the
command line so as to do batch processing of tons of
data. One of my data streams needs to be detrended.
It's a vector of numbers that follows a negative
exponential decay. I need to fit a curve to it and use
the residuals as an object. The data looks something
like this:
foo.dat
2007 Oct 29
2
help please
hello,
please can anyone help me out. Am a new user of R
program. Am having problem
with this code below, not getting the expected
results.
Each m, the cumulative sum should be 1.000 but the
2nd and 3rd m returned 2.000 and 3.000
instead of 1.000.
thanks
Aruike
pp=function(x,n,M){z=1.0;a=2.3071430;b=7.266064;H=3
out.h=c()
out.y=c()
out.m=c()
out.prob=c()
2005 Nov 08
1
Can someone Help in nls() package
Hello R-Community,
we are running aprogram to fit Non-linear differential equations to Aphid
population Data and to estimate the birth and death parameters,
here is the code:
dat<-data.frame(Time=c(0:60),Cur=c(5,6.2,59,39,38,44,20.4,19.4,34.2,35.4,38.2,48.2,55.4,113.2,
97,112,115,126,136.6,140.6,147.2,151.6,157.8,170,202,210.4,221.2,224.4,248.2,266,
2011 Dec 20
2
any DCCA function in R?
Dear members,
I am performing multivariate analysis on marine benthic populations
using R. At first glance I found ca and VEGANO packages to be the
suitable for the task, but neither has incorporated Detrended Canonical
Correspondence Analysis (DCCA), which is just the method I want to apply
on my data. I've looked for alternative packages containing the method,
but my suspicion is that
2008 Nov 24
3
count the cumulative for each subject
I have a data set like the following:
subject visit x1
1 1 0.5
1 2 1.2
1 3 0.7
2 1 0.4
2 2 0.6
2 3 1.0
.....
where x1 is the interval between the two visits. Now I want to calculate the
cumulative intervals since the beinging, for example
subject visit x1 cum
1 1 0.5 0.5
1 2 1.2 0.5+1.2
1 3 0.7 0.5+1.2+0.7
2 1 0.4 0.4
2 2 0.6 0.4+0.6
2 3 1.0 0.4+0.6+1.0
.....
is there an easy to generate the
2010 Dec 03
2
difference between linear model & scatterplot matrix
Dear R-users,
I'm studing a DB, structured like this (just a little part of my dataset):
_____________________________________________________________________________________________________________
Site
Latitude
Longitude
Year
Tot-Prod
Total_Density
dmp
Dendoudi-1
15.441964
-13.540179
2005
3271.16
1007
16993.25
Dendoudi-2
15.397321
-13.611607
2013 Nov 28
1
Relative Cumulative Frequency of Event Occurence
Hi,
My objective is to calculate "Relative (Cumulative) Frequency of Event
Occurrence" - something as follows:
Sample.Number 1st.Fly 2nd.Fly Did.E.occur? Relative.Cum.Frequency.of.E
1 G B No 0.000
2 B B Yes 0.500
3 B G No 0.333
4 G B No 0.250
5 G G Yes 0.400
6 G B No 0.333
7 B B Yes 0.429
8 G G Yes 0.500
9 G B No 0.444
10 B B Yes 0.500
Please refer to the code below:
2010 Aug 06
2
Pausing script to allow user input from keyboard.
Hi all,
I have written a simple R script to help me analyze a large data set.
I would like to have the script pause to allow the user to input a
character string that is subsequently used as a filename when saving
tables. I have tried to use the "readline" command - this seems to
work fine when entering commands one by one, but when I copy and paste
the entire script into R,
2011 Mar 07
1
species projected in a ordiplot
Dear all,
I'm performing a detrended correspondence analysis on vascular plant
community data (296 species), and I have a question on the species scores
projected in the ordination diagram. When I run a ordiplot all species are
projected in the output graph, but I'd like to restrict the number of
species plotted in the final graph. Some species are so rare in the data,
that no relevant
2015 May 17
1
The function cummax() seems to have a bug.
Hi,
The function cummax() seems to have a bug.
> x <- c(NA, 0)
> storage.mode(x) <- "integer"
> cummax(x)
[1] NA 0
The correct result of this case should be NA NA. The mistake in [
https://github.com/wch/r-source/blob/trunk/src/main/cum.c#L130-L136] may be
the reason.
Best Regards,
Dongcan
--
Dongcan Jiang
Team of Search Engine & Web Mining
School of Electronic
2010 Feb 07
1
Out-of-sample prediction with VAR
Good day,
I'm using a VAR model to forecast sales with some extra variables (google
trends data). I have divided my dataset into a trainingset (weekly sales +
vars in 2006 and 2007) and a holdout set (2008).
It is unclear to me how I should predict the out-of-sample data, because
using the predict() function in the vars package seems to estimate my
google trends vars as well. However, I want
2008 Jan 05
2
Cumulative sum of vector
Hi,
Maybe I have not been looking in the right spot, but, I have not been
able to fine a command to automatically calculate the running
cumulative sum of a vector. Is there such a command?
Example of current code:
> eig$values
[1] 678.365651 6.769697 2.853783
> prop<-eig$values/sum(eig$values)
> prop
[1] 0.986012163 0.009839832 0.004148005
>
2012 Aug 24
1
help with a special variant of balloonplot
Hi,
I am interested in implementing a special variant of
balloonplot. Let me
explain with an example dataset from the reference manual :
library(gplots)
data(Titanic)
dframe<-as.data.frame(Titanic)
survived<-dframe[dframe$Survived=="Yes",]
attach(survived)
balloonplot(x=Class,y=list(Age,Sex),z=Freq,sort=TRUE,show.zeros=TRUE,cum.margins=FALSE,
main="BalloonPlot :