Displaying 20 results from an estimated 700 matches similar to: "ordiellipse"
2011 Oct 17
1
plotting issues with PCA
Hi Listers,
This has a simple answer but it has been eluding me nonetheless.
I have been building a PCA plot from scratch with the ability to plot
predefined groups in different colors. This has worked fine but when I try
to get a polygon drawn around each of the groups it is not recognising my
colour file correctly and is only printing the first colour in the
file....code is below
2013 May 17
1
Problem with ordiellipse coloured factor in Vegan
Hello R experts,
I am trying to plot ordiellipse for my data but the col according to
factors.
Metabolites_raw= read.csv(file.choose(), head = TRUE) #file
21Metabolites.csv
Metabolites_t=t(Metabolites_raw[,2:82])
ord <- metaMDS(Metabolites_t, distance="bray")
symbol=as.numeric(Metab_metadata$LandType)
col.list <-
2011 Aug 10
1
Plotting Ellipses and Points of Matching Colors in an Ordination
Hello, R-Help -
I am trying to plot the results of an ordination from package vegan. The
tricky part for me right now is getting the colors of the ellipses denoting
the 95% confidence intervals of the group centroids to match the colors of
the points for those same groups.
>From and earlier post, I saw the code to make a plot of the ordination using
different colors for my different groups.
2006 Dec 20
2
RuleFit & quantreg: partial dependence plots; showing an effect
Dear List,
I would greatly appreciate help on the following matter:
The RuleFit program of Professor Friedman uses partial dependence plots
to explore the effect of an explanatory variable on the response
variable, after accounting for the average effects of the other
variables. The plot method [plot(summary(rq(y ~ x1 + x2,
t=seq(.1,.9,.05))))] of Professor Koenker's quantreg program
2011 Aug 04
2
Graphical option to update.packages in development version (build of the 2011-07-31 r56569) for Windows not working properly
Dear R-core/development-team,
The problem noted in the subject-line has been a problem in the last three
development versions of R for Windows that I have downloaded and tested, the
most recent of them being a version I downloaded this morning.
Update.packages() using the graphical option, i.e. called as
update.packages(ask='graphics', checkBuilt=TRUE)
does not work as it should, but
2007 Jan 09
1
contingency table analysis; generalized linear model
Dear List,
I would appreciate help on the following matter:
I am aware that higher dimensional contingency tables can be analysed using either log-linear models or as a poisson regression using a generalized linear model:
log-linear:
loglm(~Age+Site, data=xtabs(~Age+Site, data=SSites.Rev, drop.unused.levels=T))
GLM:
glm.table <- as.data.frame(xtabs(~Age+Site, data=SSites.Rev,
How to use PC1 of PCA and dim1 of MCA as a predictor in logistic regression model for data reduction
2011 Aug 17
4
How to use PC1 of PCA and dim1 of MCA as a predictor in logistic regression model for data reduction
Hi all,
I'm trying to do model reduction for logistic regression. I have 13
predictor (4 continuous variables and 9 binary variables). Using subject
matter knowledge, I selected 4 important variables. Regarding the rest 9
variables, I tried to perform data reduction by principal component
analysis (PCA). However, 8 of 9 variables were binary and only one
continuous. I transformed the data by
2011 Dec 10
3
PCA on high dimentional data
Hi:
I have a large dataset mydata, of 1000 rows and 1000 columns. The rows
have gene names and columns have condition names (cond1, cond2, cond3,
etc).
mydata<- read.table(file="c:/file1.mtx", header=TRUE, sep="")
I applied PCA as follows:
data_after_pca<- prcomp(mydata, retx=TRUE, center=TRUE, scale.=TRUE);
Now i get 1000 PCs and i choose first three PCs and make a
2011 Aug 10
3
plot 3d info in 2d
Hi Listers,
Is it possible to produce an ordination plot in 2d, where bubbles represent
the location of sites (this part is easy enough) and the size of the bubbles
is proportional to the sites location in 3d space (I am stuck on this
option). So sites that are very near the 2d plane of the xy axes would be
larger while sites that are actually further away in 3 d space would be
proportionally
2010 Oct 12
2
repeating an analysis
Hi All,
I have to say upfront that I am a complete neophyte when it comes to
programming. Nevertheless I enjoy the challenge of using R because of its
incredible statistical resources.
My problem is this .........I am running a regression tree analysis using
"rpart" and I need to run the calculation repeatedly (say n=50 times) to
obtain a distribution of results from which I will pick
2010 Nov 12
1
goodness-of-fit test
Hi All,
I have a dataset consisting of abundance counts of a fish and I want to test
if my data are poisson in distribution or normal.
My first question is whether it is more appropriate to model my data
according to a poisson distribution (if my test says it conforms) or use
transformed data to normalise the data distribution?
I have been using the vcd package
gf<-goodfit(Y,type=
2006 May 17
1
Fix for augPred/gsummary problem (nlme library)
Dear R-users,
I am a newbie to this site and a relative new-comer to S/R, so please tread lightly, for you tread...
There have been several posting relating to problems with augPred() from the nlme library. Here is a "fix" for one of these problems which may lie at the root of others.
In my case the problem with augPred() lay in gsummary(), which augPred() uses, causing it to fail.
2010 Apr 27
1
cca standard error species
Dear all,
I realised a correspondence analysis with function cca() of vegan library.
Just like in Okansen (2010) in the example of R help:
library(vegan)
data(varespec)
data(varechem)
vare.cca<-cca(varespec~ Al + P + K, varechem)
With plot.cca() function I represented the species matrix in the next way:
plot(vare.cca,display="species")
Being similar to:
plot((c(-2,2)),(c(-2,2)),
2011 Aug 09
2
reflecting a PCA biplot
Hi Listers,
I am trying to reflect a PCA biplot in the x-axis (i.e. PC1) but am not
having much success. In theory I believe all I need to do is multiply the
site and species scores for the PC1 by -1, which would effectively flip the
biplot.
I am creating a blank plot using the plot command and accessing the results
from a call to rda. I then use the calls to scores to obtain separate site
and
2012 Jan 21
2
4th corner analysis ade4 - what do the colors mean
I have used the fourthcorner function as suggest by dray and legendre
(model 2 and 4 then combine). I plot the combined value with
plot(four.comb, type="G"). What do the colors mean? I have both grey
and black bars.
many thanks,
Stephen
--
Stephen Sefick
**************************************************
Auburn University
Biological Sciences
331 Funchess Hall
Auburn, Alabama
2011 Jul 24
1
GLM different results with the same factors
I've read something about this problem, but I don't know how can i avoid this
problem.
Why the order of the factors give different results? I suppose it's because
the order of the factors, i've just changed "lcc" from the first position to
the last in the model, and the significance change completely
>
2011 Jul 13
2
Package rrcov, functions PcaCov, PcaHubert, PcaGrid
Hello,
I'm using the R-2.13.1 version in Windows and I'm trying to do a robust Pca
with the following:
x<-matrix(0.5,30,30)
library("rrcov")
y<-PcaCov(x)
The following error occurs:
Error: diff(sv)<0 ist not all TRUE
The same error occurs with the other functions. What does this mean and how
can I perform the robust PCA with these functions by using a quadratic
2011 Aug 27
3
Ordered probit model -marginal effects and relative importance of each predictor-
Hi, I have a problem with the ordered probit model -polr function
(library MASS). My independent variables are countinuos.
I am not able to understand two main points:
a) how to calculate marginal effects
b) how to calculate the relative importance of each independent variables
If required i will attach my model output.
Thanks
Franco
2012 Feb 23
1
error in fitdistr
Hi dear,
I want to estimate d.f for Chi-squared distribution:
est.chi[i,]<-c(
fitdistr(as.numeric(data2[,i]),"chi-squared",start=list(df=1))$estimate)Warning
message:In optim(x = c(7.86755, 7.50852, 7.86342, 7.70589, 7.70153,
7.58272, :
one-diml optimization by Nelder-Mead is unreliable:
use "Brent" or optimize() directly
Who can help me to solve this problem?
Best
2012 Jun 28
1
custom graphing of box and whisker plots
Hi,
I'm trying to graph some data in a boxplot-like style, but I want to set
the box and whisker limits myself (rather than having R calculate them for
me). I'd like the boxes to be shaded and the whiskers to be dotted lines.
My data are set up is something like this:
min.whisker max.whisker min.box max.box species
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