Displaying 7 results from an estimated 7 matches similar to: "how to compute uncentered (pearson correlation) correlation efficiently"
2007 May 21
1
PLS in R and SAS
Dear all:
I am comparing the PLS outputs of R and SAS for the following data set:
Y x1 x2 x3
3 6 2 2
3 1 5 5
4 7 4 1
5 6 5 6
2 4 3 2
8 5 0 9
where Y is the dependent variable and x1, x2, x3 are the independent variables. I found several PLS algorithms in R (NIPALS,SIMPLS,KERNEL PLS). SAS has SIMPLS and NIPALS.
The following are the NIPALS calculations of
2010 Dec 22
3
Estimate "between-axes" vs "within-axes heterogeneity of multivariate matrices
Hi!
My question(s) in the end might be silly but I am no expert on this, so here
it goes:
Noy-Meir (1973), Pielou (1984) and a few others have pointed to non-centered
PCA being in some cases useful. They clearly explain that "it is the case"
when multi-dimensional data display distinct clusters (which have zero, or
near-zero, projections in some subset of the axes) and the task is
2010 Nov 10
2
prcomp function
Hello,
I have a short question about the prcomp function. First I cite the
associated help page (help(prcomp)):
"Value:
...
SDEV 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).
ROTATION the matrix of variable loadings
2014 Jul 28
1
Split PVClust plot
Dear All
I'm using PVClust to perform hierarchical clustering, for the output plot I can control most of the graphical I need, however the plot is large and I would like to split it vertically into two panels one above the other. Is there a way to plot only part of a PVClust plot, I tried to convert it to a dendrogram with
result2 = as.dendrogram(result)
however I get the error message
2006 Jan 10
2
Obtaining the adjusted r-square given the regression coefficients
Hi people,
I want to obtain the adjusted r-square given a set of coefficients (without the intercept), and I don't know if there is a function that does it. Exist????????????????
I know that if you make a linear regression, you enter the dataset and have in "summary" the adjusted r-square. But this is calculated using the coefficients that R obtained,and I want other coefficients
2008 Aug 04
1
simulate data based on partial correlation matrix
Given four known and fixed vectors, x1,x2,x3,x4, I am trying to
generate a fifth vector,z, with specified known and fixed partial
correlations.
How can I do this?
In the past I have used the following (thanks to Greg Snow) to
generate a fifth vector based on zero order correlations---however I'd
like to modify it so that it can generate a fifth vector with specific
partial
2007 Sep 26
2
generate fourth vector based on known correlations
I am trying to generate a fourth vector,z, given three known and fixed
vectors, x1,x2,x3 with corresponding known and fixed correlations with
themeselves and with z. That is, all correlations are known and
prespecified. How can I do this?
Thank you,
ben