Displaying 20 results from an estimated 100 matches similar to: "metaMDS Error, Nan similar or negative values"
2010 Jan 12
1
Non-metric multidimensional scaling (NMDS) help
Hi,
I am currently working on some data and feel that NMDS would return an
excellent result. With my current data set however I have been experiencing
some problems and cannot carry out metaMDS. I have tried with a few smaller
data sets which I created for practice sake and this has worked fine.
I think it is the set up of my data set that is causing me trouble. I have
18 columns and 18 rows,
2008 May 15
1
metaMDS using Dissimilarity matrix
Hello R-user community!
I am running R 2.7.0 on a Power Book (Tiger). (I am still R and
statistics beginner)
Presently I try to run the function metaMDS (vegan) using an existing
dissimilarity-matrix.
As I would like to start with this matrix I thought I could just give
the matrix using the x= -argument
Test<-metaMDS(x=Dist.Gower)
Fehler in inherits(comm, "dist") :
2008 Dec 15
5
OT: (quasi-?) separation in a logistic GLM
Dear List,
Apologies for this off-topic post but it is R-related in the sense that
I am trying to understand what R is telling me with the data to hand.
ROC curves have recently been used to determine a dissimilarity
threshold for identifying whether two samples are from the same "type"
or not. Given the bashing that ROC curves get whenever anyone asks about
them on this list (and
2009 Jan 14
1
Howto access object of object
Dear all,
I have the following object:
> print(x)
An object of class "matrix.csr"
Slot "ra":
[1] 0.992056718 1.000000000 1.000000000 1.000000000 1.000000000 1.000000000
[7] 1.000000000 1.000000000 1.000000000 1.000000000 1.000000000 1.000000000
[13] 1.000000000 1.000000000 1.000000000 1.000000000 1.000000000 1.000000000
[19] 1.000000000 1.000000000 1.000000000
2006 Mar 27
2
Clustering question \ dist(datmat)
Hello everybody. I am trying to cluster circular data (data points which are angles), thus i can not use the "dist" function in "mclust" to generate my distance matrix, I am using the function " Dij = 0.5*( 1 - cos(theta_i - theta_j)). The thing is "hclust" will not accept this distance matrix, i tried to put it in a data frame, but again i get an error message
2006 Aug 11
1
- factanal scores correlated?
Hi,
I wonder why factor scores produced by factanal are correlated, and I'd
appreciate any hints from people that may help me to get a deeper
understanding why that's the case. By the way: I'm a psychologist used
to SPSS, so that question my sound a little silly to your ears.
Here's my minimal example:
***********************************************
v1 <-
2011 Nov 24
4
I cannot get species scores to plot with site scores in MDS when I use a distance matrix as input. Problems with NA's?
Hi, First I should note I am relatively new to R so I would appreciate answers that take this into account.
I am trying to perform an MDS ordination using the function ?metaMDS? of the ?vegan? package. I want to ordinate species according to a set of functional traits. ?Species? here refers to ?sites? in traditional vegetation analyses while ?traits? here correspond to ?species? in such
2005 Jul 23
2
cor(X) with P-Value
Friends
I am new to R (and statistics) so am struggling a bit.
Briefly...
I am interested in getting the P-Value from cor(X) where X is a matrix.
I have found cor.test.
Verbosely...
I have 4 vectors and can generate the corellation matrix...
> cor(cbind(X1, X2, X3, X4))
X1 X2 X3 X4
X1 1.00000000 -0.06190365 -0.156972795 0.182547517
X2
2011 Aug 19
1
help Dxy and C-index calculation
Dear professor,
I am currently using Design package and the cph formula for assessing
multivariable analysis.
I am tryng to get the C-index for my survival model based on Dxy
coefficient.
I am confused since there is a negative value.
Do I need to used the absolute Dxy ?
index.orig training test optimism index.corrected n
Dxy -0.341357727 -0.344002740
2005 Nov 25
1
Plotting the diff. between two curves
Dear Rs
I have two vectors A and B
where
A is
V1 d
1 0.000100000 1.123278
2 0.002186431 1.120448
3 0.004351214 1.106661
4 0.006515998 1.107713
5 0.008680781 1.107667
6 0.013010348 1.106353
7 0.019504698 1.104077
8 0.034658181 1.103202
9 0.051976447 1.103200
10 0.073624280 1.094825
11 0.093085682 1.085123
12 0.095250465 1.087325
13 0.132051782 1.086158
14 0.168853098
2005 Jan 06
5
How to avoid rounding of matrix elements?
Hi all R-users,
If I have a matrix with numeric elements as follows, the values are
rounded when I try to refer to a specifici element using [], the value
is rounded.
The same thing happens if the matrix is read from a file, the values are
stored to the correct precision but then when I try to refer to a
specific element (such as using [], it is rounded.
How do I avoid this rounding?
2009 Jul 15
1
negative Somers D from Design package
Dear R help
My problem is very similar to the analysis detailed here.
If we use the mayo dataset provided with the survivalROC package the estimate for Somer's Dxy is very negative -0.56.
The Nagelkerke R2 is positive though 0.32.
I know there is a difference between explained variation and predictive ability but I am surprised there is usch a difference given that even a non predictive model
2006 Mar 23
1
nlme for groupedData with inner and outer factors
Hello,
I am having trouble specifying a suitable nlme model.
My data structure is described by
gd <- groupedData(ppath ~ lcut | exp, outer = ~ bait, inner = ~ weight, data
= d)
i.e. the response (ppath) of several subjects (sub) was measured at levels
of a continuous variable (lcut). Subjects were given either of one level of
a factor (bait), and all subjects were measured at two levels
2005 Nov 23
1
1st derivative {mgcv} gam smooth
Dear R-hep,
I'm trying to get the first derivative of a smooth from a gam
model like:
model<-gam(y~s(x,bs="cr", k=5)+z) and need the derivative: ds(x)/dx. Since
coef(model) give me all the parameters, including the parameters of the
basis, I just need the 1st derivative of the basis s(x).1, s(x).2, s(x).3,
s(x).4. If the basis were generated with the function
2010 Jul 08
2
hi... problems about adjacency matrix
Dear all,
Hi, I have the problems about converting the matrix to adjacency matrix.Here's my example,
a b c d e fa 1.0000000 0.4048823682 0.1228531 0.49046991 0.4945158868 0.307443317b 0.4048824 1.0000000000 0.4367475 0.96949219 0.0007378596 0.560747765c 0.1228531 0.4367474719 1.0000000 0.40037341 0.3157538204
2007 Aug 28
4
Nodes & edges with similarity matrix
Hello,
I apologise if someone has already answered this but I searched and
googled but didn't find anything.
I have a matrix which gives me the similarity of each item to each
other. I would like to turn this matrix into something like what they
have in the graph package with the nodes and edges.
http://cran.r-project.org/doc/packages/graph.pdf . However I cannot find
a method to
2012 Feb 24
1
help filtering points from a scatterplot
Dear useRs,
I'm having trouble with what is likely a very simple issue with a simple graph. I have data in the format pasted below - total from which this is a subset is > 3 million rows. I'm plotting "Window" on the x axis, and either of the other two columns on the y axis. In both the second and third columns, the values are in a range from 0 to 1. I want to be able to plot
2012 Oct 29
3
multiple puppetmasters, single ca
HI all,
I am currently setting up a HA devops configuration using puppet. I want to
be able to run a single puppet master as the CA and the rest act as peering
puppet masters. I have each puppet master running on passenger and I am
proxying the SSL requests to the CA server following:
http://docs.puppetlabs.com/guides/scaling_multiple_masters.html#option-2-redirect-certificate-traffic
2011 Apr 13
1
Decimals in R/SQL
Hello,
When I am writing in sqldf or RSQLite I lose the decimals in my matrix.
The only way I can get decimals is by multiplying by 1.00000, etc. I
have tried manipulating the options, but it is only effective once I
multiply by 1.0000.
I appreciate any suggestions!
Thanks!
Example:
z <- sqldf ("select ST,
SUM(AGEP*PWGTP)*1.000000000/SUM(PWGTP)*1.00000000000000 as wgtage from
ss09
1999 Apr 09
1
eigen
Eigen seems to be giving different results in 0.64 :
eigen(matrix(
c(0.00000000, 0.0000000, 0.00000000, 1.000000000,
0.01262442, -0.1141633, 0.04989433, 0.006112607,
0.04781087, 0.4177869, -0.15569656, 0.074242237,
0.20167331, 0.2531109, -0.04973573, 0.034046467) ,4,4))$values
R:
[1] 0.35519256 -0.29294606 -0.26637369 -0.03168619
S:
[1] 0.4689288205 -0.4246063863 -0.2810596564