Displaying 20 results from an estimated 300 matches similar to: "isoMDS and 0 distances"
2009 Feb 08
2
Strange behavior of C compiled program
Hi the list,
I need to include some C code in R, but the behavior of the C code is
strange : Here is my code :
--- 8< ---
Rprintf("\n XXXX mTraj=%f
mClus=%f",mTraj[i+nbId*c],mClustersCenter[j+nbClusters*c]);
Rprintf("\nDistA=%d Tmp=%d",dist,tmp);
tmp = mTraj[i+nbId* c] - mClustersCenter [j+nbClusters* c];
Rprintf("\nDistB=%d
2013 Feb 27
1
best ordination method for binary variables
Dear all,
I'm analyzing a dataset (A) of 400 cases with 11 binary variables.
Unfortunately, several (actually a lot) of cases are identical. NA are also
present.
I want to to plot distances between cases.
For this, I obtained a distance matrix by dist(A, method="binary"). I then
analyzed the obtained distance via Principal coordinate analysis with
cmdscale(). Results are fine.
2008 Apr 01
1
lrm -interaction without main effect-error message
Dear all,
this might be not only an R-question but also a statistical.
When I do a logistic regression analysis (species distribution modeling)
with function lrm (Design package) I get the follwoing error message:
> tadl1<-lrm(triad~fd+dista+fd2+dista2+fd:dista+dista:geo2, x=T, y=T)
Error in if (!length(fname) || !any(fname == zname)) { :
missing value where TRUE/FALSE needed
The
2010 May 27
2
clustering in R
i have a matrix with the following dimensions
136 3
and it looks something like
[,1] [,2] [,3]
[1,] 402 675 1.802758
[2,] 402 696 1.938902
[3,] 402 699 1.994253
[4,] 402 945 1.898619
[5,] 424 470 1.812857
[6,] 424 905 1.816345
[7,] 470 905 1.871252
[8,] 504 780 1.958191
[9,] 504 848 1.997111...............
2002 Jan 25
1
Fw: Summary for Distance matrix by cosine?
Dear all,
below you find enclosed my message from January 9th and my program
(attention: beginner).
Thanks for both answers! a. However, as far as I know the cosine is not the
same as the Pearson correlation (only in special cases).
b. Reid Huntsinger's hint was very useful, however I had to transpose the
matrix first, for I want to calculate the distance of the _rows_.
Regards,
Petra
2004 Sep 08
8
isoMDS
Dear List:
I have a question regarding an MDS procedure that I am accustomed to
using. I have searched around the archives a bit and the help doc and
still need a little assistance. The package isoMDS is what I need to
perform the non-metric scaling, but I am working with similarity
matrices, not dissimilarities. The question may end up being resolved
simply.
Here is a bit of substantive
2007 Feb 13
4
isoMDS vs. other non-metric non-R routines
Dear useRs,
last week I asked you about a problem related to isoMDS. It turned
out that in my case isoMDS was trapped. Nonetheless, I still have
some problems with other data sets. Therefore I would like to know if
anyone here has experience with how well isoMDS performs in
comparison to other non-metric MDS routines, like Minissa.
I have the feeling that for large data sets with a high
2008 Feb 20
1
Stress with MDS
Hi,
I am looking for the best multidimensional configuration for my data (47*47
distance matrix).
I ve tried classical metric (cmdscale) and non metric MDS (isoMDS, nmds)
but it is now difficult to choose the best solution because of the
uncertainties in the definitions of the "stress" function.
So, same problem, several questions :
1. Statistical consideration : With
2008 Sep 04
2
isoMDS and dist
I am starting with a matrix in which rows are vegetation plots and
columns are various characteristics including ID# and elevation. I
removed elevation and ID columns to avoid having those characteristics
influence the distances between points which I calculated using the
"dist" command. The resulting distance file was then used in isoMDS.
What I want to know is whether I can
2004 Apr 12
1
question on isoMDS
Hello everyone,
I have a question on isoMDS.
My data set (of vegetation) with 210 samples is in this way:
Rotfoehrenau Lavendelweidenau Silberweidenau ....
067_Breg.7 0 2 0 ....
071_Dona.4 0 2 6 ....
...
I want to do an isoMDS-analysis with the dissimilarity index
2016 Apr 25
1
how to create initial configuraton for isoMDS
Hi,
I'm trying to use isoMDS to project a directed graph to 2-dim vectors, but I got an error.
#here is the code to create the graph using igraph package and run isoMDS on it.
library(igraph)
library(MASS)
g<-make_graph(c(1,2, 2,3, 2,4, 3,4, 4,5, 5,6, 3,6, 1,6, 2,5),directed=TRUE)
dist<-distances(g, mode="out")
loc<-isoMDS(dist)
# below is content of the dist matrix
2007 Jun 01
1
Beginners Question
Dear all,
I'm completely new to R and at first I must say that it is a great program!
But I have a problem with the function isoMDS from the MASS package. I
have this code which I load with source() from a file:
x <- c(163.59514923926784, 150.01448475257115, ...... {here are some
more values})
x.sort <- sort(x)
x.dist <- dist(x.sort)
library(MASS)
x.mds <- isoMDS(x.dist)
2014 Nov 06
1
limit of cmdscale function
Hi
We have a few questions regarding the use of the "isoMDS" function.
When we run "isoMDS" function using 60,000 x 60,000 data matrix,
we get the following error message:
------------------------------------
cmdscale(d, k) : invalid value of 'n'
Calls: isoMDS -> cmdscale
------------------------------------
We checked the source code of "cmdscale" and
2006 Jun 15
3
MDS with missing data?
Hello
I will be applying MDS (actually Isomap) to make a
psychological
"concept map" of the similarities between N concepts.
I would like to scale to a large number of concepts,
however, the
resulting N*(N-1) pairwise similarities is prohibitive
for a user survey.
I'm thinking of giving people random subsets of the
pairwise
similarities.
Does anyone have recommendations for this
2009 Feb 10
2
Problem installing MASS-Package
Dear R-Help-Team,
I tried to use isoMDS-Function of the MASS-Package:
Message:
Fehler: konnte Funktion "isoMDS" nicht finden
(error: could not find function "isoMDS")
so I tried to install the package MASS:
> utils:::menuInstallPkgs()
versuche URL 'http://cran.rakanu.com/bin/windows/contrib/2.8/VR_7.2-45.zip'
Content type 'application/zip' length 1598763
2001 Oct 12
1
MASS: isoMDS and sammon
If tbl is an object of class 'dist', you can do this:
a <- sammon(tbl, k=3)
But you can't do this:
b <- isoMDS(tbl, k=3)
Wouldn't it be sensible to have identical interfaces to sammon()
and isoMDS() ?
I think all that would be needed is to change this:
isoMDS <- function(d, y=cmdscale(d, 2), maxit=50, trace=TRUE)
{
...into this:
isoMDS <-
2009 Aug 30
1
about isoMDS method
Hi,
For example:
I built a half matrix "w" using a daisy(x, metric = c("euclidean"))
http://www.nabble.com/file/p25211016/1.jpg
And next I transformed this matrix "w" using isoMDS function, for example
isoMDS(w, k=2) and as result I got:
http://www.nabble.com/file/p25211016/2.jpg
And now I have two questions:
1. If number in matrix w[2, 1] (= 0.41538462) match
2008 Sep 01
1
why isoMDS not found?
When I type "isoMDS()" in the R environment, a error shows up: no such
function "isoMDS". Why? And what should I do to use isoMDS? Additionally, I
cannot install add-on packages. Typing "Rcmd.exe INSTALL e:/VR_7.2-44.zip"
results in "'perl' is neither command nor executable file...". Why this
happens?Thanks.
The setup file I downloaded is
2007 Apr 25
1
dist label names
Hello,
I am trying to do a multi-dimensional scaling of the World Bank's quality
of governance indicators for the Balkan region. I am having trouble
labelling my plot. Could some kind person help me out. How do I set the
attribute Label by a variable (say, "Code")? At present I get this:
>qog.dist<-dist(Balkans.data, method = "euclidean", diag = FALSE, upper =
2001 Dec 18
2
isoMDS: core dump (PR#1221)
I'm not sure this belong here...
Package: MASS
Version: 6.2-8
I get a core dump when I call isoMDS with an incorrect argument
for y. With d as an object of class "dist":
> isoMDS(d,2)
Program received signal SIGSEGV, Segmentation fault.
0x40229e43 in VR_mds_init_data () at MASS.c:157
--please do not edit the information below--
Version:
platform = i586-pc-linux-gnu