similar to: I: results from sammon()

Dear all, I'm trying to get a two dimensional embedding of some data using different meythods, among which princomp(), cmds(), sammon() and isoMDS(). I have a problem with sammon() because the coordinates I get are all equal to NA. What does it mean? Why the method fails in finding the coordinates? Can I do anything to get some meaningful results? Thank you very much Domenico

I'm not sure this list is the right place for this thing. I noticed some erratic behaviour in sammon(). Running sammon on two nearly identical sets of data results in very different results. Below is an example. I create an initial configuration with cmdscale() and store it into 'vec1'. I write this to file, and read it back in again to 'vec2'. According to cor() on the three

Hello, I am inputing a 17 x 17 symetric matrix to sammon. The matrix is a co-occurance matrix with no missing data. If this is at all relevant, running hclust on this matrix works. > samx <- sammon(q23axproduct) I receive the following error: Error in sammon(q23axproduct) : initial configuration must be complete In addition: Warning messages: 1: some of the first 2 eigenvalues are

Hello, I have a data set on which I run the sammon algorithm as follows: library(MASS) data = read.table('problemforr.dat') y = cmdscale(data, add=TRUE) s = sammon(data, y$points) (In case it should be relevant, I make the data available at http://idi.ntnu.no/~edsberg/problemforr.dat) With R 2.2.1 on Debian Sid I always get one of two solutions (stress 1.74288 after 10 iterations or

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 <-

Dear all, I'd like to get a linear regression of some data, and impose that the line goes through a given point P. I've tried to use the lm() method in the package "stats", but I wasn't able to specify the coordinates of the point P. Maybe I should use another method? I also have another question: How does lm() choose the point through which the output straight line goes in

When I try to run the "sammon" function of the multiv package, I always get this error message: Error in as.vector(dist(a)) : couldn't find function "dist" It happens even with example(sammon). I am running R 1.5.0 on Win98 and I have still installed R 1.4.1 but it doesn't work on the old R version with the older multiv package either. Is there a problem with the

Dear members of R-mailing list, I am using Sammon's Non-Linear Mapping in R as implemented in MASS package. I have two distance matrices (attached with the mail). For the first (/5HT_MACCS_dist.dat/) /sammon()/ works fine but for the second (/5HT_TGT_dist.dat/), I get an error message "configuration has duplicates". I checked both the matrices for duplicate values using/

The R-exts manual says about 'Suggests' field in package DESCRIPTION: "The optional `Suggests' field uses the same syntax as `Depends' and lists packages that are not necessarily needed." However, this seems to be a suggestion you cannot refuse. If you suggest packages: (a line from DESCRIPTION): Suggests: MASS, ellipse, rgl, mgcv, akima, lattice This is what happens:

Dear Mr Moderator, please let me through. I want to reply to my own thread. I once subscribed to this list, but then my subscription was not accepted. Now to the business: The final failure came from missing .install.macbinary() function. I grepped R-patched sourcesand the only instance of .install.macbinary() was the call to the function in R- patched/src/library/utils/R/packages2.R (stupid

rolf at math.unb.ca said: > If I say something like > if(x .gt. 42.d0) stop > then indeed everything stops, i.e. R falls over. I'd ***like*** to be > able to print out an informative error message (which I guess could be > done - In Fortran: subroutine foo(..., ier) integer ier ier=0 ... if (x .gt. 42.d0) then ier=1 return endif

Canberra distance is defined in function `dist' (standard library `mva') as sum(|x_i - y_i| / |x_i + y_i|) Obviously this is undefined for cases where both x_i and y_i are zeros. Since double zeros are common in many data sets, this is a nuisance. In our field (from which the distance is coming), it is customary to remove double zeros: contribution to distance is zero when both x_i

Canberra distance is defined in function `dist' (standard library `mva') as sum(|x_i - y_i| / |x_i + y_i|) Obviously this is undefined for cases where both x_i and y_i are zeros. Since double zeros are common in many data sets, this is a nuisance. In our field (from which the distance is coming), it is customary to remove double zeros: contribution to distance is zero when both x_i

I find it a bit peculiar that a package skeleton created with a utils function package.skeleton() fails subsequent R CMD check. I do understand that the function is intended to produce only a skeleton that should be edited by the package author. I think that it would be justified to say that the skeleton *should* fail the test. However, I have two arguments against intentional failure: * When you

Dear peRsons, I have a Sweave document which demonstrates the usage of step() function. With current R version 2.5.0 the step() function was changed so that the heading of trace=TRUE output for each model is printed using command message(): if (trace) message("\nStep: AIC=", format(round(bAIC, 2)), "\n",

Dear developers, I just noticed that step() function currently prints the current model using message(), but the resulting model using print(). The relevant commands within the step() body are: if (trace) message("Start: AIC=", format(round(bAIC, 2)), "\n", cut.string(deparse(as.vector(formula(fit)))), "\n") (with example() output:) Start: AIC=190.69

--==_Exmh_1801894504P Content-Type: text/plain; charset=us-ascii Dear R folks, Initially I had a plotting routine using logarithmic y-axes that failed after repeated calls if I tried to restore the graphical parameters (which I wanted to do because I used `layout' within the routine. I tried to isolate the problem and found out that the following code with logarithmic axis is sufficient for

Hi list, not really a problem to solve but a strange unwanted behavior (at least I do not like it): I'm loading library(multiv) to use sammon. Later I load library(MASS) which tells me that sammon is masked now, because there is also a MASS version of sammon. Since I believe that the MASS version is at least as good as the multiv version, I would also use the MASS version, but help(sammon)

Dear R folks, One of the fantastic new tools in R is `Sweave'. I have tested it so much that I know it works and produces fine documentation, and with (GNU) Emacs/ESS it is nice to work with, too. I started to have a look at including some Swoven (is that a strong verb?) documentation with my R package, but it seems that there is no model to copy among those packages that I have installed in

Hello all, I'm using R1.7.1 on Linux, generating sammon-optimized MDS plots from distance matrices. This is a calculation I run routinely, often on sample sets of up to 100 samples. This time, with three samples, the sammon function returned an error (shown below), which I tracked down to the cmdscale function it uses to find a starting configuration. In short, cmdscale is returning NaN