Displaying 20 results from an estimated 1015 matches for "cov".
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2012 Mar 12
3
how to calculate a variance and covariance matrix for a vector
Hello,
I have a vector {a, b1, b2, b3, b4}. How can I calculate the following
matrix:
var(a) cov(a, b1) cov(a, b2) cov(a, b3) cov(a, b4)
cov(a, b1) var(b1) cov(a, b2) cov(a, b3) cov(a, b4)
...
...
cov(a, b1) cov(a, b2) cov(a, b3) cov(a, b4) var(b4)
I would very appreciate your inputs. Thank you very much.
Sincerely,
Jialin Huang
[[alternative HTML version deleted]]
2014 Feb 21
6
[LLVMdev] make check issue with llvm-cov
...umllvm/build/test$ make
Making LLVM 'lit.site.cfg' file...
Making LLVM unittest 'lit.site.cfg' file...
( ulimit -t 600 ; ulimit -d 512000 ; ulimit -m 512000 ; ulimit -s 8192 ; \
/usr/bin/python /home/rkotler/workspace/llvm/utils/lit/lit.py -s
-v . )
XPASS: LLVM :: tools/llvm-cov/llvm-cov.test (8916 of 9784)
******************** TEST 'LLVM :: tools/llvm-cov/llvm-cov.test' FAILED
********************
Script:
--
rm -rf
/home/rkotler/caviumllvm/build/test/tools/llvm-cov/Output/llvm-cov.test.tmp
mkdir
/home/rkotler/caviumllvm/build/test/tools/llvm-cov/Output/llvm-cov...
2005 Jun 24
1
Mahalanobis distances
...a long break and have been amazed at
how much it has grown, and how active the list is! Thank you so much to all
those who contribute to this amazing project.
My question:
I am trying to calculate Mahalanobis distances for a matrix called "fgmatrix"
>dim(fgmatrix)
[1] 76 15
>fg.cov <- cov.wt(fgmatrix)
>mahalanobis(fgmatrix, center = fg.cov$center, cov = fg.cov$cov)
Then I get an error message "Covariance matrix is apparently singular"
What does this mean? I can't see anything strange about the covariance matrix,
and am not getting anywhere with the help...
2012 Jun 16
2
How to specify "newdata" in a Cox-Modell with a time dependent interaction term?
Dear Mr. Therneau, Mr. Fox, or to whoever, who has some time...
I don't find a solution to use the "survfit" function (package:
survival) for a defined pattern of covariates with a Cox-Model
including a time dependent interaction term. Somehow the definition of
my "newdata" argument seems to be erroneous.
I already googled the problem, found many persons having the same or a
similar problem, but still no solution.
I want to stress that my time-depen...
2010 Dec 20
2
For-loop
Hi,
I have the following problem:
I have a data.frame with 36 sample sites (colums) for which I have covariates in 3 categories: Area, Month and River. Each Area consists of 3 rivers, which were sampled over 3 month. Now I want to fuse River 1-3 for one area in one month. To get a data.frame with 12 colums.
I am trying to do a "for loop" (which may be a complicated solution, but I don't...
2004 Nov 17
1
Re: variations on the theme of survSplit
...rvival-splitting business, as I do, this 'survcut' function below
> might be helpful.
> It is not an elegant nor efficient function but it works, at least for
> some examples below.
>
Ditto the following, for the case where there are multiple time-varying
(irreversible) binary covariates, here slicing as coarsely as possible.
#
# Create dataset for survival analysis with time-dependent covariate
# Gill-Anderson model
#
x <- data.frame(onset=c(46, 32, 53, 76, 64, 43),
case=c(1,1,1,0,0,0),
ooph=c(NA, 30, 38, 50, NA, NA),
ocp=...
2010 Oct 11
2
Trouble accessing cov function from stats library
Dear all
I am trying to use the cov function in the stats library. I have no problem using this function from the console. However, in my R script I received a "function not found" message. Then I called stats::cov(...) and received an error message that the function was not exported. Then I tried stats:::cov (three colons)...
2010 Jun 14
2
error: subscript out of bounds?
Hi all,
I want to get results for cox proportional hazards on SNP data. I'm trying
to get HRs, CI's, & p-values for each individual SNP - this is represented
by cov[,i]. When I run my code, I get the following error: subscript out of
bounds. I don't know why I am getting this error.
I have looked through the R logs, but nothing that has been previously
suggested has helped so far. What am I doing wrong?
DS3 = time variable, S3 = censor/event variable, co...
2010 Sep 05
0
cov.unscaled in NLS - how to define cov.scaled to make comparable to SAS proc NLIN output - and theoretically WHY are they different
...IN.
proc nlin data=apples outest=a;
parms b=4 d=.04 t=180;
model Y = b/(1+exp(-d*(X-t)));
output out=b p=yhat r=yresid ;
run;
proc print data=a;
run;
A summary of the outputs:
- Same coefficients (this is a good thing)
- Same standard errors of the coefficients (also good)
- Different covariance matrices (WHY?)
I convert the cov.unscaled from R's NLS to a correlation and compare it to
SAS's correlation. They are identical;
e.g., cov2cor(summary.nls.L$cov.unscaled)
I have even written a function to convert an NLS object into a "cov.scaled"
element that is equival...
2010 Jul 19
1
Calculation of Covariance Matrix Calculation
Hi,
Excuse me for asking this silly question. But I really couldn't understand
why cov() and ccov() don't work for my calculation of covariance matrix.
a <- matrix(1:8, 2, 4)
a
[,1] [,2] [,3] [,4]
[1,] 1 3 5 7
[2,] 2 4 6 8
> ccov(a)
Error in solve.default(cov, ...) :
Lapack routine dgesv: system is exactly singular
I also tried colume bind, b...
2002 Feb 22
1
Avoiding the mean
Dear list,
what is the fastest way to compute a multivariate mean and cov-matrix? I
presume that the mean is computed in cov, so it may be a waste of time to
compute the mean first and then a second time inside of cov. Is it faster
to use cov.wt, which gives cov-matrix and center?
And: If mean and cov should be computed on a part of the data, is it faster
to use cov.wt...
2007 Oct 10
11
please help me
dear list
I am student M.S. statistics in department statistics . I am working in the function "nls" in the [R 2.3.1] with 246 data and want to fit the "exp" model to vectors( v and u ) but I have
a problem to use it
u
5.000000e-13 2.179057e+03 6.537171e+03 1.089529e+04 1.525340e+04
1.961151e+04 2.396963e+04 2.832774e+04 3.268586e+04 3.704397e+04
4.140209e+04
2006 Mar 10
1
what's wrong with my "cov"?
Hi all,
Why cov(y, y) only gives one value, and cov(t(y), t(y)) gives 3x3 NA matrix?
Here my y is listed below and it is a 3x1 matrix.
I am expecting that if I have a random vector y=[y1 y2 y3]', here " ' "
denotes a transposition so that
y is a column vector, where y1, y2, y3 are independent...
2016 Sep 21
2
-sanitizer-coverage-prune-blocks=true and LibFuzzer
...ed=2 the problem is gone.
> Looks like one of the binaries got simply unlucky with a particular seed.
> You can observe it like this:
> for S in 1 2 3 4 5 6; do ./target-asan-8bit-prune-build/fuzzer -seed=$S -runs=10000000 2>&1 | grep DONE & done
> #10000000 DONE cov: 60 bits: 91 indir: 1 units: 59 exec/s: 625000
> #10000000 DONE cov: 60 bits: 91 indir: 1 units: 57 exec/s: 588235
> #10000000 DONE cov: 253 bits: 901 indir: 12 units: 467 exec/s: 526315
> #10000000 DONE cov: 63 bits: 95 indir: 1 units: 64 exec/s: 476190
> #10000...
1998 Nov 19
1
list assignment
There appears to be a problem with name matching in list assignment:
Version 0.63.0 (November 14, 1998)
...
> r <- list()
> r$forecast.cov.trend <- 1:12
> r$forecast.cov.zero <- 1:12
> r$forecast.cov <- 1:2
> length(r$forecast.cov)
[1] 0 #should be 2
>
But note that this works correctly:
> r <- list()
> r$forecast.cov.trend <- 1:12
> r$forecast.cov <- 1:2
>...
2019 Jan 22
2
How to add new arch for llvm-cov show?
Hi all,
I'm trying to support llvm-cov for a new architecture and I have successfully built compiler-rt for my arch. Following steps shown in https://clang.llvm.org/docs/SourceBasedCodeCoverage.html , I encountered an error for the last step(step of llvm-cov show).
The command line was (supposed my arch is XXXX)
"llvm-cov show -a...
2005 Jan 13
1
how to use solve.QP
.... Or does anyone have a good example they
can send me?
Thanks so much for any hints and suggestions, Roger.
library(quadprog, lib.loc="C:\\Program Files\\R\\tools")
library(MASS, lib.loc="C:\\Program Files\\R\\tools")
n<-100
m<-200
rho<-0.7
sigma<-0.2
mu<-0.1
Cov <- matrix(rho*sigma*sigma, ncol=n, nrow=n)
diag(Cov) <- rep(sigma*sigma, n)
S <- 1+matrix(mvrnorm(m, rep(mu, n), Sigma=Cov), ncol=n)
#The problem is formulated as minimize t(b) Cov b
#subject to cLo <= A <= cUp
#and bLo=0 <= w <= 1=bUp
Cov <- var(S)
mu <- apply(S, 2, me...
2024 Oct 04
3
apply
OK. Thanks to all. Suppose I have two vectors, x and y. Is there a way
to do the covariance matrix with ?apply?. The matrix I need really
contains the deviation products divided by the degrees of freedom (n-1).
That is, the elements
(1,1), (1,2),...,(1,n)
(2,1), (2,2),...., (2,n)
....
(n,1),(n,2),...,(n,n).
> Hello,
>
> This doesn't make sense, if you have only...
2019 Jan 23
3
答复: How to add new arch for llvm-cov show?
Hi vedant,
The program didn't pass the checking "OF->getArch() != Triple(Arch).getArch()" loadBinaryFormat in CoverageMappingReader.cpp and returned an error. It's because "OF->getArch()" returned null and "Triple(Arch).getArch()" returned XXXX(name of my arch).
The returned value of " OF->getArch()" is decided by " EF.getHeader()->e_machine" but I found...
2008 Sep 05
2
typo in cov()? var() fails on NA in R 2.7.2 but not R 2.6.1
...plete.obs")
Error in var(rep(NA, 3), na.rm = T, use = "complete.obs") :
no complete element pairs
Is this change intentional? Also, what is causing it? Looking, I see
no changes in var() at all, so the new behavior must be due to a
change in what this call does:
.Internal(cov(x, y, na.method, FALSE))
The R 2.7.2 cov() also has this weird line:
else if (na.method != 3L) {
Note the "L" in the "3L". A typo? The older 2.6.1 cov() just has "3"
on that line, no "L".
Interactively redefining cov() to remove the "L" mak...