MorphoJ handles missing landmarks, but I don't think it has a function to 
estimate them. SO without an estimation of your landmark position, your options 
are either to drop the sample from the analysis (if you want to retain full set 
of landmarks) or to remove the landmark from your analysis (to keep full set of 
individuals). 

You can also experiment with trying to estimate them based on reflection (if it 
is a symmetrical structure) or based on bunch of reference samples. Both Morpho 
and gemorph in R have functions for estimating missing landmarks. See if they 
give you reliable estimates, and then you can proceed with your analysis. 

Otherwise your options are limited to those two.
M


-----Original Message-----
From: Rosa Perez [mailto:rmper...@ncsu.edu] 
Sent: Saturday, November 12, 2016 9:53 PM
To: MORPHMET <morphmet@morphometrics.org>
Subject: [MORPHMET] Re: Problem with missing data using MorphoJ

On Thursday, August 11, 2016 at 4:06:01 PM UTC-4, Jade Racine wrote:
> Dear all,
> 
> 
>  
> I digitized 108 craniofacial landmarks on human skulls from an 
> archaeological context using a MicroScribe G2X. I have a lot of random 
> missing values due to postmortem damage. I am currently trying to 
> analyze my data using MorphoJ. I followed the instructions from the 
> user’s guide, entering "-9999" in the data files for missing values. I 
> then combined the dorsal and ventral views using FileConverter. The files I 
> get can be read in MorphoJ.
> However, nothing else works. I can’t visualize the landmarks or 
> perform any kind of analysis. If I try to find outliers, I get the 
> message "Finding outliers is not possible because only a single 
> observation or none at all is available". I get this message 
> regardless of whether I upload one file with all individuals in it or 
> multiple files with one individual each. The problem seems to be with 
> the "-9999" code because if I remove the missing landmarks from my 
> data files, MorphoJ runs correctly. I tried to substitute "-9999" for 
> "9999" or "-999". MorphoJ runs fine with those but generates odd 
> results that do not look like the shape of a skull. I really want to 
> be able to analyze my dataset with missing values, otherwise I lose 
> too much landmarks and I can’t afford to remove individuals since my 
> sample is already small. Does anyone know what I am doing wrong or how I can 
> fix the problem? I attached an example of my data files.
> 
> 
>  
> 
> 
> Any help would be greatly appreciated.
> 
> 
> Thank you,
> 
> 
>  
> 
> 
> Jade Racine
> 
> 
> Master’s student
> 
> 
> Department of Anthropology
> 
> 
> University of Montreal, Canada

Hi Jade,

I am also a masters student attempting to use MorphoJ and am having a difficult 
time with the missing data. I collected 3D landmarks for a cranial asymmetry 
project and cannot get MorphoJ to run. It keeps giving me an error message. Did 
you happen to figure out what the issue was? I would truly appreciate any 
advice you might be able to share.

Thank you,

Rosa Perez
Masters Student
NCSU
Dept of Anthropology

--
MORPHMET may be accessed via its webpage at http://www.morphometrics.org
---
You received this message because you are subscribed to the Google Groups 
"MORPHMET" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to morphmet+unsubscr...@morphometrics.org.

-- 
MORPHMET may be accessed via its webpage at http://www.morphometrics.org
--- 
You received this message because you are subscribed to the Google Groups 
"MORPHMET" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to morphmet+unsubscr...@morphometrics.org.

Reply via email to