Displaying 14 results from an estimated 14 matches similar to: "prcomp: where do sdev values come from?"
2012 Apr 09
1
sdev, variance in prcomp
Hello,
It might be a trivial question but I just wanted to find out the relationship between sdev and proportion of variance generated by prcomp. I got the following result from my data set
???????????????????????????? PC1????? PC2????? PC3
Standard deviation???? 104.89454 15.40910 9.012047
Proportion of Variance?? 0.52344? 0.01130 0.003860
Cumulative Proportion??? 0.52344? 0.53474 0.538600
2011 Jun 30
2
sdev value returned by princomp function (used for PCA)
Dear all,
I have a question about the 'sdev' value returned by the princomp function (which does principal components analysis).
On the help page for princomp it says 'sdev' is 'the standard deviations of the principal components'.
However, when I calculate the principal components for the USArrests data set, I don't find this to be the case:
Here is how I
2012 Sep 02
1
why variations in accuracy between R to ARCGIS for the same point reprojection?
Hi everyone,
I wonder if anyone knows the reason why the outputs of the same
reprojection in r and arcgis are different?. The magnitude of the
change can be up to 40 km in the poles.
Basically, I have a database of points equally separated by one degree
over the globe.
In ARCGIS, I am projecting the data in GCS-WGS-1984 and then
reprojected it to Berhmann to ensure equal area
1999 Jun 30
1
qr and Moore-Penrose
> Date: Wed, 30 Jun 1999 11:12:24 +0200 (MET DST)
> From: Torsten Hothorn <hothorn at amadeus.statistik.uni-dortmund.de>
>
> yesterday I had a little shock using qr (or lm). having a matrix
>
> X <- cbind(1,diag(3))
> y <- 1:3
>
> the qr.coef returns one NA (because X is singular). So I computed the
> Moore-Penrose inverse of X (just from the
2014 Jul 29
2
Ayuda por favor
Saludos, estoy intentando usar la funciĆ³n reprojectHDF() (
http://r-gis.net/?q=ModisDownload).
####
source('ModisDownload.R')
library(raster)
library(RCurl)
path<-"~/R/MODIS/Data/Test"
input<-list.files(path,"*.hdf",all.files=T,recursive=T,full.names=T)
input
outname<-paste(substr(input[1],40,45),".tif",sep='')
outname
2004 Jul 27
4
Problems with Lapack's eigen() on 64-bit
I'm only now realizing that we have severe problems with R on our
AMD 'Opteron' and 'Athlon64' clients running Redhat Enterprise
with all 64-bit libraries (AFAICS).
The Lapack problem happens for R-patched and R-devel both on
the Opteron and the Athlon64.
Here are platform details:
o "gcc -v" and "g77 -v" both end with the line
gcc version 3.2.3
2012 Oct 24
4
Z score
Hi,
I need to find the z-score of the data present in a speardsheet. The values
needs to be calculated for each gene across the samples (refer the
example). And, it should be a simple thing, but I am unable to do it right
now !
The example re the structure of the spreadsheet is -
# Example:
MyFile <- read.csv( text=
"Names,'Sample_1','Sample_2','Sample_3'
2013 Nov 07
1
problem with interaction in lmer even after creating an "interaction variable"
Dear all,
I have a problem with interactions in lmer. I have 2 factors (garden and
gebiet) which interact, plus one other variable (home), dataframe arr. When
I put:
/
lmer (biomass ~ home + garden:gebiet + ( 1|Block), data = arr)/
it writes:
/Error in lme4::lFormula(formula = biomass ~ home + garden:gebiet + (1 | :
rank of X = 28 < ncol(X) = 30/
In the lmer help I found out that if not
2002 Mar 11
1
Spectral decomposition
Hello all,
I have the square symetric matrix A:
2 1 1
1 2 1
1 1 2
My first question is what is the easiest way to enter this matriz in R?
Second, matrix A has an eigenvalue with multiplicity 2, in this case, how
could I find the two related ortogonal eigenvectors given below by R,
without the help of R, I mean, I want to know how R calculate this
eigenvectors related to the same eigenvalue.
2008 Feb 28
2
EMM: how to make forecast using EMM methods?
Hi all,
We followed some books and sample codes and did some EMM estimation,
only to find it won't be able to generate forecast.
This is because in the stochastic volatility models we are estimating,
the volatilities are latent variables, and we want to forecast 1-step
ahead or h-step ahead volatilities.
So it is nice to have the system estimated, but we couldn't get it to
forecast at
2003 Jun 08
2
LDA: normalization of eigenvectors (see SPSS)
Hi dear R-users
I try to reproduce the steps included in a LDA. Concerning the eigenvectors there is
a difference to SPSS. In my textbook (Bortz)
it says, that the matrix with the eigenvectors
V
usually are not normalized to the length of 1, but in the way that the
following holds (SPSS does the same thing):
t(Vstar)%*%Derror%*%Vstar = I
where Vstar are the normalized eigenvectors. Derror
2012 Mar 27
1
Rgdal package - get information
>
> Hi,
>
> I used
> GDALinfo("MOD13Q1.A2001049.h13v11.005.2007002215512.250m_16_days_EVI.tif") and
> got the results:
>
> rows 10
> columns 11
> bands 1
> origin.x 150701.4
> origin.y 7744897
> res.x 250
> res.y 250
> ysign -1
> oblique.x 0
> oblique.y 0
> driver GTiff
>
2008 Jul 17
4
help with data layout
Hello list
I have been given some Excel sheets with data laid like this:
Col1 Col2
A 3
2
3
B 4
5
4
C 1
4
3
I was hoping to import this into R as a csv and then get the mean and SD for each letter in column 1.
Could someone give me some guidance on best to approach this?
Thanks
Iain
2012 Dec 29
0
thanks -- Re: syntax for identifying more than one
HI Greg,
Sorry, I misunderstand your question.
I am not sure whether it works with numSummary() from library(Rcmdr).
You could use other ways, such as:
test<-read.table(text="
?id year incidents
?100??? 1??????? 0
?101??? 1??????? 1
?102??? 1??????? 21
?100??? 1??????? 27
?101??? 1??????? 3
?102??? 1??????? 12
?100??? 2??????? 5
?101??? 2??????? 5
?102??? 2??????? 19
?100??? 2??????? 10