Re: [R] Mantel test

2015-05-06 Thread David L Carlson
object does not contain a diagonal so your comment suggests that you did not convert the matrix to a dist object. David C From: Nick Jeffery [mailto:nick.w.jeffe...@gmail.com] Sent: Wednesday, May 6, 2015 9:34 AM To: David L Carlson Subject: Re: [R] Mantel test Hi, Thanks for the help. I get

Re: [R] Mantel test

2015-05-04 Thread David L Carlson
partment of Anthropology Texas A&M University College Station, TX 77840-4352 -Original Message- From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Nick Jeffery Sent: Monday, May 4, 2015 10:49 AM To: r-help@r-project.org Subject: [R] Mantel test Dear R users, I'm havin

[R] Mantel test

2015-05-04 Thread Nick Jeffery
Dear R users, I'm having trouble getting my data into R in the correct format to run a Mantel test. I'm testing genome size differences by genetic distances of the 28S gene for ~30 species. I'm able to get my genome size data (as a single column of data) into matrix and dist formats in R but the

Re: [R] Mantel test for comparing two matrices

2013-03-19 Thread Sarah Goslee
Hi, A Mantel test doesn't test significant differences between matrices. It tests for significant correlations between dissimilarities. If your hypothesis is best expressed in terms of distances, then using the Mantel test is appropriate. As for size, 2000 by 2000 is not unmanageable, even if tho

[R] Mantel test for comparing two matrices

2013-03-18 Thread Houcemeddine Othman
Hi everyone, I have two matrices of 2000x2000 size. They consist of a measurement of RMSD deviations of a protein structure. The basic question i want to answer is the following: are there a significant differences between the two matrices? I aim to use the Mantel test. I don't really know if this

Re: [R] mantel test and NAs

2009-12-18 Thread Sarah Goslee
You will most likely need to drop the samples that are causing the NA values from both of your datasets. The function won't work with NA values. Sarah On Thu, Dec 17, 2009 at 12:33 PM, marciarocha wrote: > > Dear R users, > > I am having a problem performing the mantel test (both with functions

Re: [R] mantel test and NAs

2009-12-18 Thread Tal Galili
Could you please supply with a reproducible self sufficient script ? Contact Details:--- Contact me: tal.gal...@gmail.com | 972-52-7275845 Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | www.r-statistics

[R] mantel test and NAs

2009-12-17 Thread marciarocha
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 12 12 3 NA 4 5 6 and 1 1 2 2 3 4 5 6 7 8 Would any of you

Re: [R] Mantel test

2009-09-15 Thread Gavin Simpson
On Mon, 2009-09-14 at 23:46 -0700, swertie wrote: > oh yes of course. It is quite simple. I have two presence/absence matrices > (one for plants, one for butterflies) and I would like to test if the > butterfly community similarities is correlated with the plant community > similarities. The think

Re: [R] Mantel test

2009-09-15 Thread swertie
oh yes of course. It is quite simple. I have two presence/absence matrices (one for plants, one for butterflies) and I would like to test if the butterfly community similarities is correlated with the plant community similarities. The think is also that I don't really see the purpose of doing a PC

Re: [R] Mantel test

2009-09-14 Thread Tal Galili
Hi swertie , Could you please add more details ? What field are you at, some links maybe ? Thanks, Tal On Mon, Sep 14, 2009 at 8:30 PM, swertie wrote: > > 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

[R] Mantel test

2009-09-14 Thread swertie
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-

Re: [R] Mantel test least square line

2009-09-11 Thread swertie
Thank you it is what I was looking for. -- View this message in context: http://www.nabble.com/Mantel-test-least-square-line-tp25235402p25401329.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https:

Re: [R] Mantel test least square line

2009-09-08 Thread Jari Oksanen
swertie voila.fr> writes: > > 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?

[R] Mantel test least square line

2009-09-01 Thread swertie
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 calcu

Re: [R] Mantel test!

2009-03-03 Thread Sarah Goslee
I'm not Gavin, but since you posted this to the R-help list I assume you are open to other respondents. Since you are asking Gavin, I assume you are using mantel() from the vegan package (it's a good idea to specify, as there are other possibilities). The help for that function explains the permu

[R] Mantel test!

2009-03-03 Thread Jason Sexton
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