Displaying 20 results from an estimated 10000 matches similar to: "na.omit option in prcomp: formula interface only"
2012 Feb 09
0
na.omit option in prcomp: formula interface only
This is a wishlist/request for discussion about the behaviour of the
na.action option in prcomp, specifically the fact that it only applies
to the formula interface.
I had a question from a friend (who is smart and careful and
generally R's TFM, although like all of us he misses things sometimes)
asking why the na.action= argument didn't seem to be doing anything in
prcomp (i.e. one
2002 Oct 29
0
patch to mva:prcomp to use La.svd instead of svd (PR#2227)
Per the discussion about the problems with prcomp() when n << p, which
boils down to a problem with svd() when n << p,
here is a patch to prcomp() which substitutes La.svd() instead of svd().
-Greg
(This is really a feature enhancement, but submitted to R-bugs to make sure
it doesn't get lost. )
*** R-1.6.0/src/library/mva/R/prcomp.R Mon Aug 13 17:41:50 2001
---
2006 Mar 25
1
Suggest patch for princomp.formula and prcomp.formula
Dear all,
perhaps I am using princomp.formula and prcomp.formula in a way that
is not documented to work, but then the documentation just says:
formula: a formula with no response variable.
Thus, to avoid a lot of typing, it would be nice if one could use '.'
and '-' in the formula, e.g.
> library(DAAG)
> res <- prcomp(~ . - case - site - Pop - sex, possum)
1998 Aug 26
0
prcomp & princomp - revised
My previous post about prcomp and princomp was done in some haste as I had long
ago indicated to Kurt that I would try to have this ready for the June release,
and it appeared that I would miss yet another release. I also need to get it out
before it becomes hopelessly buried by other work.
Brian Ripley kindly pointed out some errors, and also pointed out that I was
suggesting replacing some
2009 Nov 25
1
which to trust...princomp() or prcomp() or neither?
According to R help:
princomp() uses eigenvalues of covariance data.
prcomp() uses the SVD method.
yet when I run the (eg., USArrests) data example and compare with my own
"hand-written" versions of PCA I get what looks like the opposite.
Example:
comparing the variances I see:
Using prcomp(USArrests)
-------------------------------------
Standard deviations:
[1] 83.732400 14.212402
2006 May 17
2
prcomp: problem with zeros? (PR#8870)
Full_Name: Juha Heljoranta
Version: R 2.1.1 (2005-06-20)
OS: Gentoo Linux
Submission from: (NULL) (88.112.29.250)
prcomp has a bug which causes following error
Error in svd(x, nu = 0) : infinite or missing values in 'x'
on a valid data set (no Infs, no missing values). The error is most likely
caused by the zeros in data.
My code and temporary workaround:
m = matrix(...
...
2004 Jan 15
2
prcomp scale error (PR#6433)
Full_Name: Ryszard Czerminski
Version: 1.8.1
OS: GNU/Linux
Submission from: (NULL) (205.181.102.120)
prcomp(..., scale = TRUE) does not work correctly:
$ uname -a
Linux 2.4.20-28.9bigmem #1 SMP Thu Dec 18 13:27:33 EST 2003 i686 i686 i386
GNU/Linux
$ gcc --version
gcc (GCC) 3.2.2 20030222 (Red Hat Linux 3.2.2-5)
> a <- matrix(rnorm(6), nrow = 3)
> sum((scale(a %*% svd(cov(a))$u, scale
2016 Mar 24
0
summary( prcomp(*, tol = .) ) -- and 'rank.'
Martin, I fully agree. This becomes an issue when you have big matrices.
(Note that there are awesome methods for actually only computing a small
number of PCs (unlike your code which uses svn which gets all of them);
these are available in various CRAN packages).
Best,
Kasper
On Thu, Mar 24, 2016 at 1:09 PM, Martin Maechler <maechler at stat.math.ethz.ch
> wrote:
> Following from
2004 Mar 04
1
prcomp: error code 1 from Lapack routine dgesdd
Dear all
I have a big matrix of standardized values (dimensions 285x5829) and R
fails to calculate
the principal components using prcomp() with the following error message:
pc <- prcomp(my.matrix)
Error in La.svd(x, nu, nv, method) : error code 1 from Lapack routine
dgesdd
Is the matrix too big? I'm using R-1.8.1 under Unix (Solaris8) and
Linux(Suse 8.2). I tried to
perform a principal
2006 Jun 16
2
bug in prcomp (PR#8994)
The following seems to be an bug in prcomp():
> test <- ts( matrix( c(NA, 2:5, NA, 7:10), 5, 2))
> test
Time Series:
Start = 1
End = 5
Frequency = 1
Series 1 Series 2
1 NA NA
2 2 7
3 3 8
4 4 9
5 5 10
> prcomp(test, scale.=TRUE, na.action=na.omit)
Erro en svd(x, nu = 0) : infinite or missing values in 'x'
2016 Mar 22
3
Memory usage in prcomp
Hi All:
I am running prcomp on a very large array, roughly [500000, 3650]. The array itself is 16GB. I am running on a Unix machine and am running ?top? at the same time and am quite surprised to see that the application memory usage is 76GB. I have the ?tol? set very high (.8) so that it should only pull out a few components. I am surprised at this memory usage because prcomp uses the SVD
2016 Mar 22
3
Memory usage in prcomp
Hi All:
I am running prcomp on a very large array, roughly [500000, 3650]. The array itself is 16GB. I am running on a Unix machine and am running ?top? at the same time and am quite surprised to see that the application memory usage is 76GB. I have the ?tol? set very high (.8) so that it should only pull out a few components. I am surprised at this memory usage because prcomp uses the SVD
2016 Mar 25
0
summary( prcomp(*, tol = .) ) -- and 'rank.'
As I see it, the display showing the first p << n PCs adding up to 100% of the variance is plainly wrong.
I suspect it comes about via a mental short-circuit: If we try to control p using a tolerance, then that amounts to saying that the remaining PCs are effectively zero-variance, but that is (usually) not the intention at all.
The common case is that the remainder terms have a roughly
2012 Jun 20
1
prcomp: where do sdev values come from?
In the manual page for prcomp(), it says that sdev is "the standard
deviations of the principal components (i.e., the square roots of the
eigenvalues of the covariance/correlation matrix, though the
calculation is actually done with the singular values of the data
matrix)." ?However, this is not what I'm finding. ?The values appear
to be the standard deviations of a reprojection of
2016 Mar 25
0
summary( prcomp(*, tol = .) ) -- and 'rank.'
> On 25 Mar 2016, at 10:08 , Jari Oksanen <jari.oksanen at oulu.fi> wrote:
>
>>
>> On 25 Mar 2016, at 10:41 am, peter dalgaard <pdalgd at gmail.com> wrote:
>>
>> As I see it, the display showing the first p << n PCs adding up to 100% of the variance is plainly wrong.
>>
>> I suspect it comes about via a mental short-circuit: If we
2011 Aug 17
1
prcomp
Hello
I am trying to run a PCA on the attached file, but I get this error message:
pc<-prcomp(data[,-(1:2)],scale=T)$x
Error in svd(x, nu = 0) : infinite or missing values in 'x'
Thanks in advance
/R
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2004 Apr 14
1
prcomp - error code 18
I am attempting to perform a pca on a data frame of dimension 5000x19, but
when I execute
pcapres<-prcomp(pres,center=TRUE)
the following error message is returned:
Error in La.svd(x, nu, nv, method) : error code 18 from Lapack routine
dgesdd
Where am I going wrong? I am running R-1.8.0 on Debian.
Regards,
Laura
2016 Mar 24
3
summary( prcomp(*, tol = .) ) -- and 'rank.'
Following from the R-help thread of March 22 on "Memory usage in prcomp",
I've started looking into adding an optional 'rank.' argument
to prcomp allowing to more efficiently get only a few PCs
instead of the full p PCs, say when p = 1000 and you know you
only want 5 PCs.
(https://stat.ethz.ch/pipermail/r-help/2016-March/437228.html
As it was mentioned, we already
2009 Dec 23
1
prcomp : plotting only explanatory axis arrows
Dear all,
I have a very large dataset (1712351 , 20) and would like
to plot only the arrows that represent the
contribution of each variables.
On the sample below I woild like to plot
only the explanatory variables (Murder, Assault..)
and not the sites.
prcomp(USArrests) # inappropriate
prcomp(USArrests, scale = TRUE)
prcomp(~ Murder + Assault + Rape, data = USArrests, scale = TRUE)
2004 Mar 17
0
mva :: prcomp
Dear R-list users,
I'm new to principal components and factor analysis.
I thought this method can be very useful for me to find relationships
between several variables (which I know there is, only don't know which
variables exactly and what kind of relation), so as a structure
detection method.
Now, I'm experimenting with the function prcomp from the mva package.
In my source code