Displaying 20 results from an estimated 300 matches similar to: "biplots for PCA"
2011 Feb 10
2
Prediction accuracy from Bagging with continuous data
I am using bagging to perform Bagged Regression Trees on count data (bird abundance in Britain and Ireland, in relation to climate and land cover variables). Predictions from the final model are visually believable but I would really like a diagnostic equivalent to classification success that can be used to decide if a model is adequate. Whereas with classification data an error rate is returned,
2008 Jan 17
4
things that are difficult/impossible to do in SAS or SPSSbut simple in R
Good morning,
I use SAS and R/S-Plus as my primary tools so I have a lot of experience with these programs. By far and away, SAS is superior for handling the "messy" datasets, but also the very large ones. I work at times with datasets in the hundreds of thousands (and on occasion, millions) of records. SAS, and especially PROC SQL, are invaluable for this. But once I get to
2007 Oct 09
2
Help with gamm errors
Dear All
Hopefully someone out there can point out what I am missing! I have a
(large, several hundred) dataset of gardens in which over two years the
presence/absence of a particular bird species is noted each week. I have
good reason to believe there is a difference between the two years in the
weekly proportion of gardens and would like to assess this, before going on
to look in more detail at
2008 Jan 14
6
Ceiling to the nearest ten?
R-users,
Is there a function for ceiling to the nearest ten?
a <- 1:10*4
a
[1] 4 8 12 16 20 24 28 32 36 40
The resulting vector should look like this ("ceiling to the nearest ten")
[1] 10 10 20 20 20 30 30 40 40 40
Thanks in advance
Lauri
2007 Nov 21
2
Reconstruct array dataset
Hi there
I have an interesting problem:
My csv file is of array dimensions [12,50], but it was saved the wrong way: there should be only 11 colums. What happens now if I read it into R is that the whole data set is shifted ( in the first row, the last column contains already the first value of the supposed second row and so on...)
how can I tell R to switch after 11 read values to the next row,
2011 Feb 18
0
Weights in bagged regression trees
Has anyone any experience of applying observational weights in bagging? I am performing regression trees (continuous data on bird abundance) and need to account for sampling intensity. In a single tree, i.e. a call of rpart, I can specify weights either by having a separate vector called weights, or by a variable called weights in the dataframe under analysis. Both produce sensible (and identical)
2009 Feb 04
2
data editor in R- could it be improved?
Hi all,
I've used R for basic programming and data management for a few years now. One of the things that I think could be improved is the data editor.
Its a great feature and I use it alot by calling edit(data.frame); very useful to see if what you tried to do actually worked.
However, one of the annoying things about it is that when you scroll down the window it doesnt show you all the
2009 Feb 19
4
type III effect from glm()
Hi all,
This could be naivety/stupidity on my part rather than a problem with model output, but here goes....
I have fitted a fairly simple model
m1<-glm(count~siteall+yrs+yrs:district,family=quasipoisson,weights=weight,data=m[x[[i]],])
I want to know if yrs (a continuous variable) has a significant unique effect in the model, so I fit a simplified model with the main effect ommitted...
2009 May 29
1
data manipulation involving aggregate
hi all,
I often have a data frame like this example
data.frame(sq=c(1,1,1,2,2,3,3,3,3),area=c(1,2,3,1,2,3,1,2,3),habitat=c("garden","garden","pond","field","garden","river","garden","field","field"))
for each "sq" I have multiple "habitat"s each with an associated "area".
I
2009 Jan 22
1
help using zeroinfl()
Hi all,
I have been trying to use zeroinfl() with the pscl package with R version 2.1.1. and with the newest versions of the contrib packages compatible with R 2.1.1.
I have read the examples, the vignette and all the posts relating to zeroinfl() but I am still confused as to how to structure the model.
Here is a small example; the error message is the same for big data sets
2009 Jun 18
1
win.metafile() and family
Hi all,
I recently discovered how great win.metafile is for getting high resolution graphics into word.
Having problems with specifying families though...
#pdf works fine
pdf("test.pdf",width=14,height=9)
par(family="Helvetica")
plot(1:10)
text(4,4,"trial")
dev.off()
windows
2
#metafile doesnt like helvetica family
2006 Dec 24
2
db name change
Hi all,
Is it possible to do a db name change during the course of the
project and then propagate the effect all across the project?
E.g. I started of doing a sample program with db name as
"tests". As the project evolved I decided to change its name to "biodatas".
" create_table "tests", :force => true do |t|
t.column
2009 Mar 10
1
help structuring mixed model using lmer()
Hi all,
This is partly a statistical question as well as a question about R, but I am stumped!
I have count data from various sites across years. (Not all of the sites in the study appear in all years). Each site has its own habitat score "habitat" that remains constant across all years.
I want to know if counts declined faster on sites with high "habitat" scores.
I can
2009 Apr 09
1
reading an image and adding a legend
Hi all,
I would like to
1. Read in an arcmap image into R (I can export pretty much any type of image jpeg, bitmap etc from arcmap)
2. Use R to create a nice colour legend in the plot
First of all, Is this possible?
So far I'm stuck on point 1. I have tried read.pnm() from pixmap and read.jpeg() from rgl.
the pnm example provided works fine
x <-
2005 May 30
4
Script to convert mboxes to maildirs?
Does anybody know of a script of a simple method of
converting mbox mail stores to maildirs? I'm moving
from an old pop3 system to imap and after installing
about half our office with mboxes have found that mbox
does not support subfolders which some people like to
use.
Is there any simple way of converting? I can go to
each individual account and "manually" convert swaping
data
2002 Jan 29
0
Biplots for non-normal data
Hello,
we have a large data set of water quality data and want to identify
influence variables or *why* different groups of data are different (in
an explorative sense).
We consider to use biplots, however there are only the common
PCA-Biplots available in R (biplot.princomp).
We consider to use transformations (log-type, x^a, Box-Cox), but are
seeking for alternatives.
Are there
2005 Apr 28
0
Linear Discriminant Analysis Biplots
Dear R
I'm trying to plot the lda means onto a 2 D plot of discriminant scores.
Preferably I'd like these to be in a larger font compared to the
discriminant scores.
I tried
skull.mean.pred <- predict(skulls.lda, as.data.frame(skulls.lda$means),
dimen=2)
from which I got
skull.mean.pred
$class
[1] 1 2 3 4 5
Levels: 1 2 3 4 5
$posterior
1 2 3 4
2003 Mar 10
2
Biplots
I want to plot biplots. I have seen the function biplot, but there are
some extra features I would like, that I do not know how to achieve.
1. My observations, and my variables, fall into groups. Is there a way to,
say, plot the observations in several different colours, according to
which group the observation falls into? Similarly with the variables? I am
used to the lattice idiom, in which one
2007 Sep 21
1
problem with 'integrate'
Hello -
I am having a problem with the function 'integrate'. I am running R
on OSX (R 2.5.1).
I am trying to suppress the error message when 'integrate' attempts
to integrate across a parameter set giving a non-finite function
value. I'm using it in a MCMC / simulated annealing algorithm, and
it is entirely possible that some parameter sets will give non-