A new statistical method for the comparison of biplots with the same objects and variables

Ordinations are compared most commonly by Procrustes methods applicable to points belonging to the same domain, either the objects or the variables describing them. However, no published approach applies to biplots which visualize principal component ordinations of objects and variables simultaneous...

Full description

Bibliographic Details
Main Authors: Attila István Engloner, János Podani
Format: Article
Language:English
Published: Elsevier 2023-10-01
Series:Ecological Indicators
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S1470160X23009445
_version_ 1797683103164006400
author Attila István Engloner
János Podani
author_facet Attila István Engloner
János Podani
author_sort Attila István Engloner
collection DOAJ
description Ordinations are compared most commonly by Procrustes methods applicable to points belonging to the same domain, either the objects or the variables describing them. However, no published approach applies to biplots which visualize principal component ordinations of objects and variables simultaneously.To fill this gap, this paper provides a new procedure based on two fundamental, scale-invariant properties of biplots: the cosine of the angle between the vectors pointing to every pair of objects and variables and the mean of the relative length of the two vectors. The method applies to situations in which the number of objects is the same in all ordinations, the number of variables is also the same and, additionally, there is one-to-one correspondence between the points in the different ordinations. The new method is illustrated with two artificial examples and is also applied to the comparison of biplots obtained from real field data representing samples repeated in the same locations over time.It is demonstrated that the new method reveals the similarities and differences between alternative biplots obtained for a given set of objects and variables.We expect that, thanks to the widespread use of principal component analysis in science, the method will receive applications in any studies in which interest lies in the comparison of simultaneous ordinations of objects and variables.
first_indexed 2024-03-12T00:10:37Z
format Article
id doaj.art-e5fc9e0dceb745c8a831957f6baa8e1a
institution Directory Open Access Journal
issn 1470-160X
language English
last_indexed 2024-03-12T00:10:37Z
publishDate 2023-10-01
publisher Elsevier
record_format Article
series Ecological Indicators
spelling doaj.art-e5fc9e0dceb745c8a831957f6baa8e1a2023-09-16T05:30:00ZengElsevierEcological Indicators1470-160X2023-10-01154110802A new statistical method for the comparison of biplots with the same objects and variablesAttila István Engloner0János Podani1Institute of Aquatic Ecology, Centre for Ecological Research, Karolina út 29, Budapest H-1113, Hungary; Corresponding author.Department of Plant Systematics, Ecology and Theoretical Biology, Institute of Biology, Eötvös University, Pázmány P. s. 1/c, H-1117 Budapest, Hungary; Institute of Evolution, Centre for Ecological Research, Budapest, HungaryOrdinations are compared most commonly by Procrustes methods applicable to points belonging to the same domain, either the objects or the variables describing them. However, no published approach applies to biplots which visualize principal component ordinations of objects and variables simultaneously.To fill this gap, this paper provides a new procedure based on two fundamental, scale-invariant properties of biplots: the cosine of the angle between the vectors pointing to every pair of objects and variables and the mean of the relative length of the two vectors. The method applies to situations in which the number of objects is the same in all ordinations, the number of variables is also the same and, additionally, there is one-to-one correspondence between the points in the different ordinations. The new method is illustrated with two artificial examples and is also applied to the comparison of biplots obtained from real field data representing samples repeated in the same locations over time.It is demonstrated that the new method reveals the similarities and differences between alternative biplots obtained for a given set of objects and variables.We expect that, thanks to the widespread use of principal component analysis in science, the method will receive applications in any studies in which interest lies in the comparison of simultaneous ordinations of objects and variables.http://www.sciencedirect.com/science/article/pii/S1470160X23009445Euclidean distanceOrdinationPrincipal components
spellingShingle Attila István Engloner
János Podani
A new statistical method for the comparison of biplots with the same objects and variables
Ecological Indicators
Euclidean distance
Ordination
Principal components
title A new statistical method for the comparison of biplots with the same objects and variables
title_full A new statistical method for the comparison of biplots with the same objects and variables
title_fullStr A new statistical method for the comparison of biplots with the same objects and variables
title_full_unstemmed A new statistical method for the comparison of biplots with the same objects and variables
title_short A new statistical method for the comparison of biplots with the same objects and variables
title_sort new statistical method for the comparison of biplots with the same objects and variables
topic Euclidean distance
Ordination
Principal components
url http://www.sciencedirect.com/science/article/pii/S1470160X23009445
work_keys_str_mv AT attilaistvanengloner anewstatisticalmethodforthecomparisonofbiplotswiththesameobjectsandvariables
AT janospodani anewstatisticalmethodforthecomparisonofbiplotswiththesameobjectsandvariables
AT attilaistvanengloner newstatisticalmethodforthecomparisonofbiplotswiththesameobjectsandvariables
AT janospodani newstatisticalmethodforthecomparisonofbiplotswiththesameobjectsandvariables