Displaying 20 results from an estimated 29 matches for "legendre".

2008 Sep 27

3

Double integration - Gauss Quadrature

...tegrate(function(y) {
sapply(y, function(y) {
integrate(function(x) x*y, 0, 1)$value
})
}, 0, 1)
but I would like to use Gauss Quadrature to do it.
I have written the following code (using R's statmod package) which
works fine for one integral but it doesn't work for a double one:
# Gauss-Legendre abscissas
nodes <- gauss.quad.prob(25,dist="uniform",l=-1,u=1)$nodes
# and weights
weights <- gauss.quad.prob(25,dist="uniform",l=-1,u=1)$weights
weights <- weights*2
# Approximate integral of f from a to b using Gauss-Legendre
gauss_legendre<-function(f,a,b,nodes,...

2012 Jun 06

2

pregunta sobre libro de Legendre

Hola a todos,
Por casualidad alguno que tenga el libro de Legendre de Numerical Ecology
with R sabe dónde o cómo bajar los data sets que se mencionan para seguir
los ejemplos?
Muchas gracias por su ayuda!
----
*Angela Andrea Camargo Sanabria*
Estudiante Doctorado en Ciencias Biológicas
Laboratorio de Ecología de poblaciones y comunidades tropicales
Centro de Inve...

2010 Sep 21

1

partial dbRDA or CCA with two distance objects in Vegan.

...lyse
genetic distance data ( provided as a dist object calculated using
dist.genpop in package adegenet) with geographic distance partialled out
( provided as a distance object using dist function in veganthis method
is attempting to follow the method used by Geffen et al 2004 as
suggested by Legendre and . FORTIN (2010).
I cannot see how to introduce the Conditioning ( partialled) second dist
matrix. as you can see from the code snippet below, the two dist
objects are of the same dimensions. - I get an error using capscale:
Error in qr.fitted(Q, Xbar) :
'qr'...

2007 Mar 21

2

Gaussian Adaptive Quadrature

Hi all,
Does anybody know any function that performs gaussian adapative quadrature integration of univariate functions?
Thanks in advance,
Regards,
Caio
__________________________________________________
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2015 May 27

4

[Bug 2302] with DH-GEX, ssh (and sshd) should not fall back to unconfigured DH groups or at least document this behaviour and use a stronger group

...know if there's a reason other than blind-spec-compliance. Pointers?
>
> Regards,
>
> --dkg
One reason the generator of the full (Z/pZ)* is avoided is because
knowledge of g^a and g^b (both known to Mallory) leaks information about
the shared secret g^(ab) via their legendre symbols. This is
particularly troublesome in the context of El Gamal.
I don't have a reference to recommend off-hand but you might want to
google for "decisional diffie hellman assumption".
--mancha
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2004 Jun 23

0

chronological clustering

Does anybody know of any R functions to perform chronological clustering
as explained in:
Legendre, P., S. Dallot & L. Legendre. 1985. Succession of species
within a community: chronological clustering, with applications to
marine and freshwater zooplankton. American Naturalist 125: 257-288.
http://www.fas.umontreal.ca/BIOL/legendre/reprints/succession_of_species.p...

2005 Aug 08

2

INDVAL and mvpart

Hi,
I'd like to perform Dufrene-Legendre Indicator Species Analysis for
a multivariate regression tree. However I have problems with arguments
of duleg(veg,class,numitr=1000)function. How to obtain a vector of
numeric class memberships for samples, or a classification object
returned from mvpart?
thanks in advance
--
Best regards,
Agn...

2013 Aug 22

1

varpart

Dear R-users
I applied vegan's varpart function to partition the effects of
explanatory matrices. Adj. R square for the unique fraction [a] is
0.25. Does anyone know why the decomposition by hand using rda gives
me a different result for [a] (constrained proportion is 0.32)? I used
cbind() for the conditional fractions, but it should be similar to
condition()?
Thanks very much

2007 Feb 27

2

RDA and trend surface regression

Dear all,
I'm performing RDA on plant presence/absence data, constrained by
geographical locations. I'd like to constrain the RDA by the "extended
matrix of geographical coordinates" -ie the matrix of geographical
coordinates completed by adding all terms of a cubic trend surface
regression- .
This is the command I use (package vegan):
>rda(Helling ~

2001 Apr 10

5

Similarity matrix

I frequently use hclust on a similarity matrix. In R only a
distance matrix is allowed. Is there a simple reliable
transformation of a similarity matrix that will result
in a distance matrix making hclust work the same as
S-Plus with a similarity matrix? Venables & Ripley 3rd
edition implies that a simple reversal of values
will suffice. Thanks -Frank
--
Frank E Harrell Jr

2008 Feb 28

1

intermediate linkage clustering

Does anybody know how to do a intermediate linkage clustering in R?
Is there a command allready developed? Which package do I have to load?
Thanks in advance
yvo
--
View this message in context: http://www.nabble.com/intermediate-linkage-clustering-tp15736379p15736379.html
Sent from the R help mailing list archive at Nabble.com.

2011 Jan 25

0

Multivariate polynomials Howto

Good Evening,
I would like to work with multivariate polynomials (x and y variables).
I know that there is a package called multipol but I am not sure that supports my needs.
I use a function (in reality legendre.polynomials) which creates me the polynomials I want.
For example the following returns
> legendre.polynomials(2)[[2]]
x (first order polynomial)
I would like to calculate the polynomials with variable x with the polynomials with variable y. I do not know how I can do that in R as my function...

2013 Apr 30

1

vegan -varpart is bigger than 100% in total?

I am trying to find the percentage of the parameters explaining the bacterial community composition. I have one data matrix with relative abundance of OTUs and one with environmental parameters. I used varpart in vegan package but the values in the venn diagram is bigger than 100% in total.How is it possible? What might be the reason? Thank you
library(vegan)
gotud <-

2015 Jun 12

2

[Bug 2302] with DH-GEX, ssh (and sshd) should not fall back to unconfigured DH groups or at least document this behaviour and use a stronger group

On Fri 2015-06-12 01:52:54 -0400, Mark D. Baushke wrote:
> I have communicated with Allen Roginsky on this topic and I have been given permission to post his response.
>
> In this message below, the 'vendor' was Darren Tucker's generated prime
> that used a generator value of 5.
>
> -- Mark
>
> From: "Roginsky, Allen" <allen.roginsky at

2005 Jun 30

1

nfs install : kernel panic

...installs, but it tells me
"ftp://192.168.0.6//mnt/centos/(...)/net2(...).sys don't exist"
(remark the two // after the ip address, both in ftp & http installs. i
tried to do mnt/centos but the installer
told me "no!").
thanks,
legendre renald

2008 Aug 01

1

3 opportunities open for Full Time positions in Toronto, Canada

...k, company paid beverages (POP, Juice, Coffee,
Tea). Good work environment. Position 1 may include occasional travel to
European and Caribbean locations.
We are looking to fill these positions as soon as possible. Please forward your resume if you believe you have the skill set required.
Colin Legendre CCNP, MCP
Manager, Infrastructure Management Services
Net Present Services Ltd.
e: clegendre@netpresentservices.com <mailto:clegendre@netpresentservices.com>

2013 Oct 11

3

Gaussian Quadrature for arbitrary PDF

Hi all,
We know that Hermite polynomial is for
Gaussian, Laguerre polynomial for Exponential
distribution, Legendre polynomial for uniform
distribution, Jacobi polynomial for Beta distribution. Does anyone know
which kind of polynomial deals with the log-normal, Student抯 t, Inverse
gamma and Fisher抯 F distribution?
Thank you in advance!
David
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2011 Mar 28

1

ordination in vegan

Hi all,
I have site data with plant species cover and am looking for trends. I'm
kind of new to this, but have done lots of reading and can't find an answer.
I tried decorana (I know it's been replaced by ca.) and see a trend, but I'm
not sure what it means. Is there a way to get the loadings/eigenvectors of
the axes (like in PCA)? Is there a way to do this with rda() too?

2013 May 02

2

rda variance partioning in vegan problems

This is not a request for coding help so there is no reproducible code,
rather I am trying to figure out if anyone had had a similar experience.
My question is related to partitioning the variance in rda (vegan) results
for multiple groups of variables. I have a high dimensional dataset with
79 explanatory variables and 9 response variables. Within those 79
explanatory variables there are ~8

2013 Dec 17

1

What is the formula of Pseudo-F statistic in capscale in vegan?

...DifView
1.4892
1.7299
VolAuton
2.2923
2.2925
(2) pseudo-F formula
We know that PRIMER uses the following formula to calculate the pseudo-F for
a sequential test of significance (equation 4.3, Anderson, Gorley, and
Clarke 2008, Chapter 4. Pg. 129, and based on pseudo-F equation in Legendre
and Anderson (1999), Ecological Monographs vol. 69):
F= (SSFull - SSReduced)/(qFull-qReduced)
(SSTotal-SSFull)/(N - qFull - 1)
(3) R code
## creating Bray-Curtis of Biodiversity data
H.BC <- vegdist(H.Full [,14:211], "bray")
## Distance based redundancy ana...