Displaying 20 results from an estimated 1950 matches for "stressful".
2011 Mar 10
1
3 dimensional MDS plots
Hi,
I am trying to create 3 mds plots: one with axis 1 vs axis 2, one with axis 2 vs axis 3, and one with axis 1 vs axis 3. When inputting my code, I only end up with one diagram and when inputting
mdsg.mds$dims, the program returns 2 for 2 dimensions. How can I create the other two plots?
Any help would be greatly appreciated,
Calla Carbone
The table I use is number of each taxa on each
2019 May 24
2
Representations of IR in the output of opt
Hi LLVM,
I'm currently setting up some tools to investigate the influence of the
order of optimization passes on the performance of compiled programs
-nothing exceptional here.
I noticed something inconvenient with opt, namely that splitting a call
does not always give the same output:
% llvm-stress > stress.ll
% opt -dse -verify -dce stress.ll -o stress-1.bc
% opt -dse stress.ll |
2006 Dec 11
2
How to write a two-way interaction as a random effect in a lmer model?
Dear All,
I am working with linear mixed-effects models using the lme4 package in
R. I created a model with the lmer function including some main effects,
a two-way interaction and a random effect. Now I am searching how I
could incorporate an interaction between the random effect and one of
the fixed effects.
I tried to express the interaction in:
2019 May 27
2
Representations of IR in the output of opt
Hi Eli,
Unfortunately the differences remain, I do not observe a significant
change in the output besides the fact that it's random.
I noticed that running opt without options on the random file changes
the order of references in the predecessors of basic blocks (sample
below). Further invocations of opt are idempotent.
I don't know of this information is stored in the bytecode file
2001 Nov 01
1
Erratic behaviour of sammon()
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
2010 Sep 17
1
How to find STRESS criteria in MDS when there are negative eigenvalues....
Hi,
I want to know whether there is any function in R to find STRESS after using cmdscale and estimating the coordinates, I have written these functions to find stress (for p =1,2,3,4,5)
stress<-rep(0,5)
for(p in 1:5)
{
datahat<-cmdscale(d,p)
deltahat<-as.matrix(dist(datahat))
a<-0
b<-0
for(i in 1:n)
{
for(j in 1:n)
{
a<-d[i,j]^2+a
b<-(d[i,j]-deltahat[i,j])^2+b
}
}
2003 Apr 20
1
survreg penalized likelihood?
What objective function is maximized by survreg with the default
Weibull model? I'm getting finite parameters in a case that has the
likelihood maximzed at Infinite, so it can't be a simple maximum
likelihood.
Consider the following:
#############################
> set.seed(3)
> Stress <- rep(1:3, each=3)
> ch.life <- exp(9-3*Stress)
> simLife <- rexp(9,
2005 Jan 23
4
survreg: fitting different location parameters
Hi R-Help!
My question: I have lifetime/failure data of machines with different
stress levels and i think an weibull/extreme value distribution would
fit this data. So I did:
model1 <- survreg(Surv(lfailure)~stress,data=steel,dist="extreme")
(where lfailure=log(failure))
Now I would like to do a likelihood ratio test to test the hypothesis
H0: location parameters of the
2019 May 27
2
Representations of IR in the output of opt
Hi Mehdi,
Thank you for mentioning this tool, I was looking for something like
this. By default the analyzer produces identical output on both files,
but a complete -dump shows that the storage order of the symbol table is
different.
This would explain why text files are not affected: the symbols are used
directly in text form so there is no need for this table.
I suppose that settles the
2006 Dec 07
1
domU''s crashing Dom0 (Xen + iSCS = timebomb)
I''m experimenting with xen + iscsi, and I founded that under heavy stress
domU''s can crash entire system, I''ve reproduced this many many times.
My system is like this
Software:
- iSCSI Enterprise Target v0.4.13
- RedHat AS4 update 4 64bit + Xen 3.0.3-0 Kernel 2.6.16.29 + Open iSCSI
v2.0.730 (Initiator)
- Bonnie++ v1.03a
VM:
- Debian 3.1r3 + Open iSCSI v2.0.730
2005 Nov 04
1
Stress in multidimensional scaling
Hello,
We are trying to find a function to compute "stress" in our
multidimensional scaling analysis of a dissimilarity matrix. We've used
"dist()" to create the matrix and "cmdscale()" for the scaling. In order
to determine the number of dimensions we would like to plot stress vs.
dimensions. However, we cannot find a pre-made command. It seems that
other
2003 Apr 14
1
isoMDS and stress
Hi all,
I try to calculate the stress of a configuration using the formula in
the isoMDS help, but I don't have the same result than the stress
returned by isoMDS :
> library(mva)
> library(MASS)
> data(swiss)
> swiss.x <- as.matrix(swiss[,-1])
> swiss.dist <- dist(swiss.x)
> swiss.mds <- isoMDS(swiss.dist)
initial value 2.979731
iter 5 value 2.431486
iter 10
2010 Jul 22
1
interpretation of stress in NMDS
Among those users of Primer, stress values greater than 0.3 are
interpreted as "questionable". Using both isoMDS and metaMDS (vegan
package), the stress values returned are much higher using my own data
and using examples provided in R Help. For example Rstress = 8.3, and
the stressplot r2 = 0.99 indicating (to me) that the ordination is OK.
I am guessing that the "stress"
2006 Jan 30
1
Varying results of sammon(), for the same data set
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
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
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
2007 Nov 13
3
Stress-Testing Asterisk
Hi All,
I was wondering, what tools are readily available out
there in Asteriskland for me to use in stress/load
testing asterisk box I have in the lab. I want to
observe how my box holds out under heavy/light/medium
load.
Thanks,
Jeng
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2012 Mar 19
2
by output into data frame
I could do this in various hacky ways, but what's the right way?
I have a nice application of the by function, which does what I want. The output looks like this:
> auc_stress
lab.samples.stress$subid: 2
cortisol amylase
1 919.05 6834.8
---------------------------------------------------------------------------------------------------------------------------
2007 Jan 23
2
stress-test realtime voicemail with sipp
We are in the process of implementing realtime voicemail. I was wanting
to "stress-test" the system to see if or when it would fall over.
Is it possible to use sipp to create say 250 calls, each of which leaves
a message in the voicemail ?
My dialplan is currently
[default]
exten => stress,1,Answer()
exten => stress,2(vm),Voicemail(7777|su)
exten => stress,3,Hangup()
2009 Feb 17
2
Stress Testing IVR
Hi,
How can I stress test an asterisk IVR? I am looking for some kind of
sip phone which can be "programmed" to send out digits after specified
time to simulate users pressing menu items. If it can originate large
number of calls simultaneously then it's great!
Does any one have any recommendations ? Any other method to stress
test an IVR call flow?
with regards,
raj