Displaying 20 results from an estimated 400 matches similar to: "from table to matrix"
2011 Dec 03
1
partial mantel tests in ecodist with intential NA values.
I would like to perform partial mantel tests on only within group values, with "between group" values assigned to NA.
This is possible in package ncf partial.mantel.test, however this sues a different permutation to that used in ecodist.ecodist will not accept data with NA values, returning a "matrix is not square error.
is it possible to perform this test in ecodist?
many thanks
2011 Feb 20
8
Generating uniformly distributed correlated data.
I wish to generate a vector of uniformly distributed data with a
defined correlation to another vector
The only function I have been able to find doing something similar is
corgen from the library ecodist.
The following code generates data with the desired correlation to the
vector x but the resulting vector y is normal and not uniform
distributed
library(ecodist)
x <- runif(10^5)
y
2008 Apr 14
1
Vegan R^2 and tau values for metaMDS
I am using the function metaMDS with jaccard distances to ordinate a
set of constituent by site matrix. I can post this data if it would
be helpful, but it is large to include in an email. I can also
provide reproducable code if necessary. I would like to get an R^2
value for the axes of the ordination configuration that I get with
metaMDS in the vegan package is there a way to do this- is it
2011 Oct 16
2
How to plot CI's (llim ulim) on ecodist mgram
I would like to put confidence intervals on a mantel corellogram
they are already calculated in the pmgram object but I am unsure how I
get the x value in order to plot them?
package(ecodist)
X<-1:100
Y<-rnorm(1:100)
Z<-rnorm(1:100)
XY<-dist(data.frame(X,Y))
YX<-dist(data.frame(Y,X))
my.mgram<-mgram(XY,XZ)
plot(my.mgram)
print(my.mgram)
> print(my.mgram)
$mgram
2007 Oct 17
1
correlated data
Hi!!
I am trying to generate data with specific correlation using corgen method from the ecodist package. It does not seem to generate the data properly. I am listing the code below. Secondly, when I put the code given below all in one file and source it, it is unable to complete the task. But when I execute it one at a time it is able to complete it. Can someone point out any mistake that I may
2011 Jan 20
1
Problems with ecodist
Dear Dr.Goslee and anyone may intrested in matrix manipulate,
I am using your ecodist to do mantel and partial mantel test, I have
locality data and shape variation data, and the two distance matrixs are
given as belowings. When I run the analysis, it is always report that the
matrix is not square, but I didn't know what's wrong with my data. Would you
please help me on this. I am quite
2007 Nov 16
4
Permutation of a distance matrix
Hi there,
I would like to find a more efficient way of permuting the rows and columns of a symmetrical matrix that represents ecological or actual distances between objects in space. The permutation is of the type used in a Mantel test.
Specifically, the permutation has to accomplish something like this:
Original matrix addresses:
a11 a12 a13
a21 a22 a23
a31 a32 a33
Example
2012 Jun 28
2
Size of subsample in ecodist mantel()
What is the size of the boostrapped subsample in ecodist mantel()
thanks
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2012 Feb 27
1
How to incorporate interaction terms in MRM function of ecodist library?
Hi,
I'm interested in incorporating some interaction terms between my
explanatory variables (distance matrices in this case) when I'm using the
function MRM of the package ecodist. The function is doing a multiple
regression on distance matrices. I can get the function to work perfectly on
my explanatory matrices by adding a (+) sign as known. However, when I try
to use the (*) sign or
2009 May 08
2
partial mantel tests "Ecodist"
Hi all,
I'm searching for a little clarification on partial mantel tests
(ecodist package)
I've a distance matrix (x,y), and several others containing
environmental/chemical variables.
Based on the help file, and the package instructions I've managed to
implement the tests as;
var1 ~ env1 + space
to partial out the effect of space and test the relationship between
the
2011 Oct 04
2
Adonis and nmds help and questions for a novice.
Hi,
forgive me if someone has already posted about this but I have had a look and cannot find the answer, also I am very new to R and been getting the grips with this.
I have been trying to use Adonis to find out if there are significant difference between groups on data that I have analyses with NMDS, and have been struggling with getting this to work and understanding what is going on. I am
2007 Jun 12
4
Generating artificial datasets with a specific correlation coefficient.
I need to create artificial datasets with specific correlation
coefficients (i.e. a dataset that returns r = 0.30, etc.) as examples
for a lab I am teaching this summer. Is there a way to do that in R?
Thanks.
Jim Milks
Graduate Student
Environmental Sciences Ph.D. Program
136 Biological Sciences
Wright State University
3640 Colonel Glenn Hwy
Dayton, OH 45435
[[alternative HTML version
2018 May 08
2
Bilateral matrix
I have data on current and previous location of individuals. I would like
to have a matrix with bilateral movement between locations. I would like
the final output to look like the second table below.
I have tried using crosstab() from the ecodist but I do not have another
variable to measure the flow. Ultimately I would like to compute the
probability of movement between cities (movement to
2012 Aug 02
1
sapply and matrix command
HI,
You can also try this:
d<-1:25
A<-sample(combn(20:30,2))
B<-sample(combn(20:30,2))
lapply(d,function(x) matrix(c(1,A[x],B[x],1),2,2))
[[1]]
[,1] [,2]
[1,] 1 23
[2,] 27 1
[[2]]
[,1] [,2]
[1,] 1 21
[2,] 21 1
[[3]]
[,1] [,2]
[1,] 1 29
[2,] 23 1
[[4]]
[,1] [,2]
[1,] 1 25
[2,] 20 1
[[5]]
[,1] [,2]
[1,] 1 23
[2,]
2003 Sep 12
2
partial mantel
Dear all,
Has anyone written R code for partial Mantel Tests- as described for
instance in Legtendre & Legendre (1998) ?
In other words, in a community ecology analysis, I would like to calculate
the correlation between two dissimilarity matrices, controlling for a third
distance matrix representing geographical distances between sites.
Thanks!
Christophe Bouget
Biodiversité et gestion des
2010 Nov 04
3
avoid a loop
Let's suppose I have userids and associated attributes... columns a and b
a <- c(1,1,1,2,2,3,3,3,3)
b <- c("a","b","c","a","d","a", "b", "e", "f")
so a unique list of a would be
id <- unique(a)
I want a matrix like this...
[,1] [,2] [,3]
[1,] 3 1 2
[2,] 1 2 1
[3,]
2012 Mar 22
1
How do you distinguish between characters on a pco plot?
I have a presence/absence matrix for which I create a distance matrix and
then perform pco analysis on.
/library(ecodist)
table <- read.table("matrix.pa")
dist <- dist(table, method = "euclidean", diag = FALSE, upper = FALSE)
dist.pco <- pco(dist)/
When I plot the pco analysis of the distance matrix I want to be able to
distinguish between certain characters, for
2018 May 08
3
Bilateral matrix
or in base R : ?xtabs ??
as in:
xtabs(~previous_location + current_location,data=x)
(You can convert the 0s to NA's if you like)
Cheers,
Bert
Bert Gunter
"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
On Tue, May 8, 2018 at 9:21 AM, Huzefa
2018 May 16
0
Bilateral matrix
Dear Bert and Huzefa,
Apologies for the late reply, my account got hacked and I have just managed
to recover it.
Thank you very much for your replies and the solutions. Both work well.
I was wondering if there was any way to ensure (force) that all possible
combinations show up in the output. The full dataset has 25 cities but of
course people have not moved from Boston to all the other 24
2018 May 08
0
Bilateral matrix
Dear Miluji,
If I understand correctly, this should get you what you need.
temp1 <-
structure(list(id = 101:115, current_location = structure(c(2L,
8L, 8L, 3L, 6L, 5L, 1L, 2L, 7L, 4L, 2L, 8L, 8L, 3L, 6L), .Label =
c("Austin",
"Boston", "Cambridge", "Durham", "Houston", "Lynn", "New Orleans",
"New York"), class =