What is CoDA?
...parts of a whole...
Compositional Data Analysis (CoDA) refers to the analysis of compositional data (CoDa), which have been defined historically as random vectors with strictly positive components whose sum is constant (e.g., 100, one, a million). More recently, the term covers all those vectors representing parts of a whole which only carry relative information, thus including not only parts per unit or percentages, but also molar compositions.
Typical examples in different fields are: geology (geochemical elements), economy (income/expenditure distribution),
medicine (body composition: fat, bone, lean), questionnaire surveys (ipsative data), food industry (food composition: fat, sugar, etc), chemistry (chemical composition), ecology (abundance of different species), paleontology (foraminifera taxa), agriculture (nutrient balance ionomics), sociology (time-use surveys), environmental sciences (soil contamination), and genetics (genotype frequency). This type of data appears in most applications, and the interest and importance of consistent statistical methods cannot be underestimated. Although the concern of the problems related to them was kept alive mainly by researchers from the field of Geosciences, in particular by members of the International Association for Mathematical Geosciences, the awareness of coherent methods is growing in the environmental and biological sciences.
Why choose us
...forum for the exchange...
This hot topic of research has nowadays a broad impact in these fields. However, it took a long time to find a solution to the problem of how to perform a proper statistical analysis of this type of data, i.e. to solve the problem of the spurious correlation, as it was named by Karl Pearson back in 1897, or the closure problem as called by Felix Chayes in the 1960's. Because standard statistical techniques loose their applicability and classical interpretation when applied to compositional data, new techniques were needed. No theoretically sound solution was proposed until the 1980's, when John Aitchison set forth a consistent theory based on log-ratios. Later developments have shown that the mathematical foundation of a proper statistical analysis for this type of data is based on the definition of a specific geometry on the simplex (the sample space of compositional data). Based on it, is possible to rigorously develop any statistical analysis (cluster analysis, discriminant analysis, factor analysis, regression models, to mention just a few).
Practitioners interested in CoDa find in this web site a forum for the exchange of information, material and ideas.
This web site has been planned, and is currently maintained, by the members of the
Research Group on Compositional Data Analysis
at the Dept. Informàtica, Matemàtica Aplicada i Estadística
(IMAE-UdG) under the
projects COmpositional Data Analysis and RElated meThOdS (CODA-RETOS) and COmpositional and Spatial Data Analysis (COSDA).
The core of the group belongs to the University of Girona (UdG),
and includes members from the Technical University of Catalonia (UPC),
and Biomathematics & Statistics Scotland (BioSS). All the researchers whose interest goes from real case studies to the mathematical foundations of CoDA are welcomed! Join us!
Work team
...let's start working on...
Vera Pawlowsky-Glahn
PhD in Mathematics. Full Professor (UdG).
Germà Coenders
PhD in Management Sciences. Titular Professor (UdG).
Jan Graffelman
PhD in Statistics. Titular Professor (UPC).
Glòria Mateu-Figueras
PhD in Statistics. Associated Professor (UdG).
Santiago Thió-Fdz.-de-Henestrosa
PhD in Computer Science. Titular Professor (UdG).
Juan José Egozcue
PhD in Physics. Full Professor
(UPC).
Pepus Daunis-i-Estadella
PhD in Statistics. Titular Professor (UdG).
Eusebi Jarauta
PhD in Industrial Engineering. Titular Professor (UPC).
Maribel Ortego
PhD in Mathematics. Associated Professor (UPC).
Marina Vives-Mestres
PhD in Statistics. Researcher and part-time university lecturer (UdG).
Carles Barceló-Vidal
PhD in Statistics. Emeritus Professor (UdG).
Berta Ferrer-Rosell
PhD in Tourism. Visiting lecturer at University of Lleida (UdL).
Josep A. Martín-Fernández
PhD in Statistics. Titular Professor (UdG).
Javier Palarea-Albaladejo
PhD in Statistics. Senior Statistical Scientist (BioSS).
Who is Who?
...some CoDa-people...
Name:Albanese, Stefano Albanese
Email: stefano.albanese@unina.itAddress: VIA MEZZOCANNONE 8Institution: Univesità di Napoli FEDERICO II
Position: Professor
Name:Albayrak, Serkan Albayrak
Email: rfsrkn@gmail.comAddress: IzmirInstitution: Yasar University
Position: Assistant Professor
Name:Asis, Constancio
Email: asis.tony@gmail.comAddress: 2 Calder Court, Malak, NT AustraliaInstitution: Department of Primary Industry and Fisheries Northern Terriotory Government Australia
Position: Senior Research Agronomist
Name:Barceló-Vidal, Carles
Email: carles.barcelo@udg.eduAddress: Dept. IMAE, Edifici P4, Campus Montilivi, E-17071 Girona (Spain)Institution: Universitat de Girona
Position: Emeritus Titular Professor
Name:Cardoso, Margarida
Email: margarida.cardoso@iscte.ptInstitution: ISCTE-IUL
Position: Professor
Name:carpita, stefano
Email: carpitastefano@gmail.com
Name:Christie, Mario
Email: christie.mario@yahoo.comAddress: 275 7 West Greater Portmore POInstitution: University of the West Indies, Mona
Position: Student
Name:Comas-Cufí, Marc
Email: mcomas@imae.udg.eduAddress: Dept. IMAE, Edifici P4, Campus Montilivi, E-17071 Girona (Spain)Institution: Universitat de Girona
Name:Darabi-Golestan, Farshad
Email: pcdar2000@yahoo.comInstitution: Amirkabir University of technology
Position: Ph.D. candidate
Name:Daunis-i-Estadella, Pepus
Email: pepus@imae.udg.eduAddress: Dept. IMAE, Edifici P4, Campus Montilivi, Carrer Univ. de Girona, 6 E-17003 Girona (Spain)Institution: Universitat de Girona
Name:dr, Nidhi Gupta
Email: NGU@nrcwe.dkAddress: Lerso Parkelle 105Institution: nrcwe
Position: researcher
Name:Edjabou, Vincent
Email: vine@env.dtu.dkInstitution: DTU
Position: Student
Name:Egozcue, Juan José
Email: juan.jose.egozcue@upc.eduAddress: Enginyeria Civil i Ambiental, EDIFICI C2, PLANTA 3, C. JORDI GIRONA, 1-3, 08034 BARCELONA (Spain)Institution: Universitat Politècnica de Catalunya
Position: Full Professor
Name:Evans, Jedy
Email: jedyevans@gmail.comAddress: NAInstitution: African Institute for Mathematical Sciences
Position: Student
Name:Fisch, Greg
Email: Gfisch9862@aol.com
Name:Flood, Rory
Email: rflood02@qub.ac.uk
Name:Franquet, Álvaro
Email: alvarofranq@gmail.comInstitution: Universitat de Girona
Name:Fry, Tim
Email: tim.fry@rmit.edu.auAddress: School of Economics, Finance and Marketing, RMIT University, GPO Box 2476, Melbourne VIC 3001 AustraliaInstitution: RMIT University
Position: Full Professor
Name:Gong, Peng
Email: 360464454@qq.com
Name:Hood, Shawn Hood
Email: Shawn.Hood@utas.edu.auAddress: 1 Ascot AveInstitution: University of Tasmania
Position: PhD Research
Name:Jama, Saed
Email: siciid522@hotmail.comAddress: TurkeyInstitution: Anadolu university
Position: Student
Name:James, John
Email: johnandlucyjames@mac.comAddress: 6464 South Downing Street Centennial, CO 80121 USAInstitution: Neisseria Research, LLC
Position: Microbiologist
Name:kenett, ron
Email: ron@kpa-group.comInstitution: KPA and UNITO
Position: Research Professor
Name:Kuzik, Nicholas
Email: nkuzik@ualberta.caInstitution: University of Alberta
Position: Graduate Student
Name:Lo, Ernest
Email: ernest.lo@inspq.qc.caInstitution: McGill University, Institut National de Santé Publique du Québec (INSPQ)
Name:Manhães, Marco
Email: marcomanhaes@bol.com.br
Name:MARCILLO, JUAN
Email: caperuzo23@gmail.comAddress: BarcelonaInstitution: UPC
Position: student
Name:Martín-Fernández, Josep-Antoni
Email: josepantoni.martin@udg.esAddress: Dept. IMAE, Edifici P4, Campus Montilivi, E-17071 Girona (Spain)Institution: University of Girona
Position: Titular Professor
Name:MENDES, AURIO
Email: auriomende00s@gmail.comInstitution: UEM
Name:Monti, Gianna
Email: gianna.monti@unimib.itAddress: Dep. of Economics, Management and Statistics (DEMS), Via Bicocca degli, Arcimboldi 8, 20126 Milano, ItalyInstitution: University of Milano-Bicocca
Position: Assistant Professor
Name:Núñez, Héctor
Email: hector.mantilla@geopinar.gms.minem.cuAddress: Ave 57 # 14003 apto 5 e/ 140 y 142 Marianao, La Habana, CubaInstitution: GeomineraPinar
Position: Geólogo
Name:Ordonez-Calderon, Juan Carlos
Email: ordonez.jc@gmail.comAddress: Suite 800-25 York Street, ToroInstitution: Hudbay
Position: Exploration Geochemist
Name:Ortego-Martínez, Maribel
Email: ma.isabel.ortego@upc.eduAddress: Dep. Enginyeria Civil i Ambiental, EDIFICI C2, PLANTA 3, C. JORDI GIRONA, 1-3, 08034 BARCELONA (SPAIN)Institution: Universitat Politècnica de Catalunya
Name:Palarea Albaladejo, Javier
Email: javier@bioss.ac.ukInstitution: Biomathematics and Statistics Scotland
Name:panda, santanu
Email: santanu20@gmail.comAddress: IndiaInstitution: GSI
Position: Geologist
Name:Pawlowsky-Glahn, Vera
Email: vera.pawlowsky@udg.eduAddress: Dept. IMAE, Edifici P4, Campus Montilivi, E-17071 Girona (Spain)Institution: University of Girona
Position: Full Professor
Name:Plata Rincón, Catalina
Email: catalinaplatar@gmail.comInstitution: Universidad Santo Tomás
Name:Sajdak, Marcin
Email: msajdak@ichpw.zabrze.plInstitution: Institute for Chemical Processing of Coal (ICPC )
Position: Eng.&Tech. specialist
Name:SUAREZ, CARLOS
Email: carlos.suarez1973@yahoo.esAddress: EL CONDEInstitution: PARTICULAR
Position: INVESTIGADOR
Name:THIOMBANE, MATAR
Email: thiombane.matar@unina.itAddress: Via mezzocanone, 16 4th floor NaplesInstitution: University Federico II Naples-Italy
Position: PhD Student
Name:Tsagris, Michael
Email: pmxmt1@nottingham.ac.ukInstitution: Unisersity of Nottingham
Position: PhD student
Name:Vezzoli, Giovanni
Email: giovanni.vezzoli@unimib.itAddress: Dipartimento di Scienze dell Ambiente e del Territorio e di Scienze della Terra, Piazza della Scienza, 4 20126 Milano (Italy)Institution: University of Milano-Bicocca
Position: Geologist Researcher