Displaying 5 results from an estimated 5 matches for "ev2".
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2007 Jul 27
2
Matrix Multiplication, Floating-Point, etc.
Hi.
I recently tried the following in R 2.5.1 on Windows XP:
>ev2<-c(0.8,-0.6)
>ev1<-c(0.6,0.8)
>ev1%*%ev2
[,1]
[1,] -2.664427e-17
>sum(ev1*ev2)
[1] 0
>
(I got the same result with R 2.4.1 on a different Windows XP machine.)
I expect this issue is very familiar and probably has been discussed in this
forum before. Can someone p...
2013 Jun 18
1
eigen(symmetric=TRUE) for complex matrices
...; eigen(A,T)$vectors -> e
> crossprod(e)[1:4,1:4]
also:
> crossprod(A,solve(A))
[and the associated commands with A+0i in place of A], give errors of
order 1e-14 or less.
I think the eigenvectors are misbehaving too:
> eigen(A,T)$vectors -> ev1
> eigen(A+0i,T)$vectors -> ev2
> range(Re((A %*% ev1[,100])/ev1[,100]))
[1] 2.497662e-10 2.566555e-10 # min=max mathematically;
differences due to numerics
> range(Re((A %*% ev2[,100])/ev2[,100]))
[1] -19.407290 4.412938 # off the scale errors
[note the difference in sign]
>
F...
2008 Jan 16
1
Error in plot.new() : figure margins too large
Hi
I am getting error :
Error in plot.new() : figure margins too large
Can you please help
-----code is ------------------------------------------------------------
temp <- seq(5500000/2, 22000000, 5500000/2)
sV2 <- c(1, 1+temp[-length(temp)])
eV2 <- temp
i=1
bitmap(paste("c:/vidhu/poster/poster_56half_2", LETTERS[i], ".png", sep =
""), "png256", width = 55.5, height = 8.875, res = 300)
par(mfrow = c(28,1), mar = c(0.5,3,0.5,0.5), mgp = c(2,0.65,0))
for(i in 1:length(sV2)) {
cat("i =...
2015 Nov 05
1
[PATCH 1/2] test-data: phony-guests: Don't use *.tmp.* temporary files.
---
test-data/phony-guests/Makefile.am | 3 +--
test-data/phony-guests/make-archlinux-img.sh | 4 ++--
test-data/phony-guests/make-coreos-img.sh | 10 ++++----
test-data/phony-guests/make-debian-img.sh | 10 ++++----
test-data/phony-guests/make-fedora-img.pl | 34 ++++++++++++++--------------
test-data/phony-guests/make-ubuntu-img.sh | 14 ++++++------
2012 Jul 03
8
[PATCH 0/7 v2] Fix and workaround for qcow2 issues in qemu causing data corruption.
https://bugzilla.redhat.com/show_bug.cgi?id=836710
https://bugzilla.redhat.com/show_bug.cgi?id=836913
There are at least two related bugs going on:
(1) Linux sync(2) system call doesn't send a write barrier to the
disk, so in effect it doesn't force the hard disk to flush its cache.
libguestfs used sync(2) to force changes to disk. We didn't expect
that qemu was caching anything