Displaying 20 results from an estimated 1000 matches similar to: "problem with data for metaMDS analysis please help"
2008 Apr 23
0
Problem with Species x Site matrix please help
I am at my wit's end. I am not sure what is wrong with this data matrix.
It is sparse because it is a matrix of species, but I have looked at the row
totals and column totals and they are positive.
metaMDS(x.d)
Error in if (autotransform && xam > 50) { :
missing value where TRUE/FALSE needed
What is wrong? And in the future how in God's name do I easily diagnose
whatever
2011 Aug 20
2
a Question regarding glm for linear regression
Hello All,
I have a question about glm in R. I would like to fit a model with glm function, I have a vector y (size n) which is my response variable and I have matrix X which is by size (n*f) where f is the number of features or columns. I have about 80 features, and when I fit a model using the following formula,?
glmfit = glm(y ~ x1 + x2 + x3 + x4 + x5 + x6 + x7 + x8 + x9 + x10 + x11 + x12 + x13
2018 Mar 14
2
truncation/rounding bug with write.csv
I don't see the issue here. It would be helpful if people would report
their sessionInfo() when reporting whether or not they see this issue.
Mine is
> sessionInfo()
R version 3.4.3 (2017-11-30)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Arch Linux
Matrix products: default
BLAS/LAPACK: /usr/lib/libopenblas_haswellp-r0.2.20.so
locale:
[1] LC_CTYPE=en_US.UTF-8
2018 Mar 14
2
truncation/rounding bug with write.csv
Hello, I have looked on https://www.r-project.org/bugs.html , but it seems
that this is the only way to do it.
The issue is that the precision used by write.csv is on consistant for big
files. See the following code:
First I create a large dataframe filled with random uniform values. Then I
write it to .csv and print out the first and last lines.
df = data.frame(replicate(100, runif(1000000,
2018 Mar 14
2
truncation/rounding bug with write.csv
To my surprise, I can confirm on Windows 10 using R 3.4.3 . As tail is not
recognized by Windows cmd, I replaced with:
system('powershell -nologo "& "Get-Content -Path temp.csv -Tail 1')
The last line shows only 7 digits after the decimal, whereas the first have
15 digits after the decimal. I agree with Dirk though, 1.6Gb csv files are
not the best way to work with
2008 Dec 30
1
why stress value remains so high after invoking of metaMDS
Hello everyone!
metaMDS(cm, distance = "euclidean", k = 2, trymax = 50, autotransform
=TRUE, trace = 1, plot = T)
(cm is a similarity matrix, in which values are positive integers or 0)
I use this command to run NMDS on my matrix "cm". But the stress is very
high after analysis. About 14.
Actually, there is no improvment comparing with using isoMDS.
2007 Aug 24
1
Adding new points to a metaMDS ordination ("vegan" pkg)
Hi, I've been using R for a while now but I've got a problem with
metaMDS (in the vegan package) that I can't quite figure out.
I have a set of proportion data (from 0-1, rows sum to 1) that I apply
metaMDS to using the command:
nMDS.set=metaMDS(sqrt(test.set),distance="euclidean",k=3,zerodist="add",autotransform=FALSE)
I am using a squared-chord distance
2013 May 27
1
metaMDS with large dataset produces 'insufficient data' warning
Greetings everyone,
I am running MDS on a very large dataset (12 x 25071 - 12 model runs with 25071 output values each), and also on a very much reduced version of the dataset (randomly select 1000 of the 25071 output values). I would like to look at similarities/dissimilarities between the 12 model runs. When I use metaMDS on the full dataset, I get a warning message:
Warning message:
In
2004 May 11
1
calling data frames
Dear List,
I've around 1000 *.txt files, I've generate with other software.
I've now done the following code (below).
My question is how can I automate this (with do.call () ?), so it could be
done for all the *.txt files.
Thanks in advance,
Rog??rio
names<- list.files()
file <- "BLU_Var_%04d.txt"
for(i in 1:1000){
2010 May 11
1
Help with Names
Hi - a newbie question, if someone can please help....
I want to change X1, X2,,.....to X.1 X.2 etc in the names below. I am using
the Principal Component Regression function (pcr) and it seems to want it
this way
> datap3.pcr <- pcr(water ~ X, 10, data = datap3, Validation ="cv")
Error in model.frame.default(formula = water ~ X, data = datap3) :
invalid type (list) for
2008 Dec 29
0
stress value remains so high(metaMDS)
metaMDS(cm, distance = "euclidean", k = 2, trymax = 50, autotransform =TRUE,
trace = 1, plot = T)
(cm is a similarity matrix, in which values are positive integers or 0)
I use this command to run NMDS on my matrix "cm". But the stress is very
high after analysis. About 14.
Actually, there is no improvment comparing with using isoMDS.
2013 Apr 05
1
Accessing examplars in apcluster (apcluster package)
Hi,
I was wondering how it was possible to access the actual cluster exemplars
from the APResult class. Currently it only spits it out onto the terminal
if you type the object but there is no other way to see which one is the
examplar.
Would appreciate any help.
Thanks,
Sachin
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2011 Jun 01
1
as.character limits length of result for formula
If you want a character representation of a long formula (or
a formula with long names), you can use:
as.character(my.formula)
However restriction on length of an as.character result
returns only the beginning of a long formula, and without comment.
In most cases, the following expression provides the complete
result:
paste(my.formula[[2]], " ~ ",
2013 Apr 12
2
model frame and formula mismatch in model.matrix()
Hello everyone,
I am trying to fit the following model
All X. variables are continuous, while the conditions are categoricals.
model <- lm(X2
2011 May 10
3
metaMDS and envfit: Help reading output
Hello R experts,
I've used metaMDS to run NMDS on some fish abundance data, and am also working on correlating environmental data to the NMDS coordinates. I'm fairly new to metaMDS and NMDS in general, so I have what are probably some very basic questions. My fish abundance data consists of 66 sites for which up to 20 species of fish were identified and counted. I ran metaMDS on this data
2012 Aug 08
1
basehaz() in package 'Survival' and warnings() with coxph
Hello,
I have a couple of questions with regards to fitting a coxph model to a data
set in R:
I have a very large dataset and wanted to get the baseline hazard using the
basehaz() function in the package : 'survival'.
If I use all the covariates then the output from basehaz(fit), where fit is
a model fit using coxph(), gives 507 unique values for the time and the
corresponding cumulative
2009 Jun 24
2
change the height or scale of the y axis
Hallo, All,
I have a question about changing the height or scale of the y axis. When I
use following two R codes, I can get two plots. Please look at the y axes,
the number of indices (x1, x2, ?) on the y axis in the first plot is smaller
than that in the second plot, and hence the space between any two indices in
the first plot is wider than that in the second plot. As the number of
indices
2012 Aug 09
1
basehaz() in package survival and warnings with coxph
I've never seen this, and have no idea how to reproduce it.
For resloution you are going to have to give me a working example of the
failure.
Also, per the posting guide, what is your sessionInfo()?
Terry Therneau
On 08/09/2012 04:11 AM, r-help-request at r-project.org wrote:
> I have a couple of questions with regards to fitting a coxph model to a data
> set in R:
>
> I have a
2012 May 25
2
Query about creating time sequences
Hi All,
I have a query about time based sequences. I know such questions have been
asked a lot on forums, but I couldnt find the exact thing that I was
looking for.
I want to create a time-based sequence which will mimic the trading window
AND would span multiple days. Something like below:
"2011-01-03 09:15:00 IST"
"2011-01-03 09:15:01 IST"
....
....
....
"2011-01-03
2009 Oct 06
1
previous.best in metaMDS
Dear R-community, dear Jari Oksanen!
I use metaMDS (package vegan) to calculate NMDS.
In a lot of papers I read that it is recommended to use previous best solutions as a new starting configuration to get better results and to avoid local minima.
On the help page I found that a previous.best-command is already implemented in metaMDS:
metaMDS(comm, distance = "bray", ...,plot = FALSE,