similar to: Size of subsample in ecodist mantel()

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

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

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

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

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

Dear Gavin, What is the interpretation of a simulated p-value of 1 in a mantel test and how is the p-value derived? When we run two highly negatively correlated matrices we get this result: r: -1, simulated p value: 1 I would expect the high p-value of 1 to mean not significant. Could you clarify? Thank you, Jason Jason P. Sexton Graduate Group in Ecology University of California,

Hello, I am working with two datasets with ~5,200 observations. Apparently, neither the correlog function (ncf package) nor the mantel function (ecodist package) can handle these datasets. Does anyone have any experience about the maximum number of observations these functions can handle? I am considering partitioning them into smaller subsets. This would not be an ideal

Hi I am using PXELinux to boot BartPE and some other application and it works fine. There are some other Boot application which I am using 3COM MBAUTIL PXE.mnu and floppy images. I have problem chaining from pxelinux.0 to 3com pxe.0 (pxe.mnu). Consider: BIOS->(DHCP-TFTP)->pxelinux.0 works fine. BIOS->(DHCP-TFTP)->3COM pxe.mnu works fine, the menu appears and I can choose a floppy

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

Hi, I'm trying to write a code (see below) to randomly resample measurements of one variable (say here the variable "counts" in the data frame "dat") with different resampled subsample sizes. The code works fine for a single resampled subsample size (in the code below = 10). I then tried to generalize this by writing a function with a loop, where in each loop the function

Dear R users, I am having a problem performing the mantel test (both with functions mantel {vegan} and mantel.test {ape}) due to I believe the presence of NAs on my distance matrices, which look like e.g.: NA 1 2 1 2 3 NA 4 5 6 and 1 1 2 2 3 4 5 6 7 8 Would any of you have a solution for that? Thank you for much for your help! Marcia Rocha -- View this message in

Hello, I performed a Mantel test and plotted communitiy similarities. I would like to add a least square line. I thought about using abline taking as slope the r-statistic of the Mantel test and calculating the y-intercept analytically. Is this method correct? Is there any function for this calculation? Thank you -- View this message in context:

I'm trying to perform a mantel test that ignores specific pairs in my distance matrices. The reasoning is that some geographic distances below a certain threshold suffer from spatial autocorrelation, or perhaps ecological relationships become less relevant that stochastic processes above a certain threshold. The problem is that I can't find a way to do it. If I replace values in either or

Hello! It is not really linked to R, but can somebody explain me why we sometimes make a mantel test directly for to distance matrices and sometimes we first make a gradient analysis and then a mantel test between the axis? Thank you -- View this message in context: http://www.nabble.com/Mantel-test-tp25439984p25439984.html Sent from the R help mailing list archive at Nabble.com.

Does anyone know of an R function for computing the Greenland-Robins variance for Mantel-Haenszel relative risks? Thanks Frank -- Frank E Harrell Jr Professor and Chair School of Medicine Department of Biostatistics Vanderbilt University

Hi there, I'm dealing with a pretty big dataset (~22,000 entries) with numerous entries for every day over a period of several years. I have a column "judy" (for Julian Day) with 0 beginning on Jan. 1st of every new year (I want to compare tendencies between years). However, in order to control for a leap year (2004), I simply need to subtract 1 from every judy value for the year

Hi all! I have an ordered vector of values. The distribution of these values can be modeled by a sum of Gaussians. So I'm using the package 'mclust' to get the Gaussians's parameters for this 1D distribution. It works very well, but, for input sizes above 100.000 values it starts taking really forever. Unfortunately my dataset has around 4.6M values... My question: is it

Hi all, Does anyone know if an R function for the Mantel-Haenszel chi-square for a 2x2 table exists? I’ve also seen it called the randomization Q statistic. Note that I’m not looking for the Cochran-Mantel-Haenszel…I did see that out there as cmh.test. Thanks in advance, Jeff Internal Virus Database is out-of-date. Checked by AVG Free Edition. 11:27 AM [[alternative HTML version

I would like to know how to run a partial mantel test controlling for spatial autocorrelation and correlation with other environmental variables. It seems that with function included in vegan for partial mantel test I can only test for the relationship between two variables controlling for the effect of a third one. Thanks a lot Alexandra --- Lic. Alexandra Sapoznikow Centro Nacional

Dear Sir/ Madam, I would like to ask you about mantel test in R. In ade4 package, if I want to use mantel.rtest, I get error massage "Object of class to "dist" expected". As I already have two dissimilarity matrices, shall I again compute distance measure using this function? If not, could you please let me know which function/command I can use to do? Thank you very much in