My field of research is focused in general on multivariate data analysis, and more specifically biplots and graphical visualisation of multi-dimensional data. My research is both on theoretical developments of methods for visualisation of multi-dimensional data, R software developed to implement methods and applications leading to new extensions of current methodology.

After a 13-year stint in the corporate world, I moved to academia in July 2009 as associate professor at the University of Cape Town and in January 2017, I joined Stellenbosch University as professor in statistics. I am an elected member of the International Statistics Institute, served on the executive committees of the International Federation of Classification Societies and the International Association of Statistical Computing. I am also the chair of the Multivariate Data Analysis Special Interest Group in the South African Statistical Association.

In July 2011 we formalised our research group into the Centre for Multi-dimensional Data Visualisation (MuViSU) located in the Department of Statistics and Actuarial Science at Stellenbosch University. As director of MuViSU I am proud to say we have a network of national and international members as well as post graduate students working on a variety of collaborative research projects.


BOOKS

Warning: package 'gt' was built under R version 4.5.2
Authors Year Title Publisher
Le Roux, N.J. and Lubbe, S. 2025 An Introduction into R Applications and Programming: A Tutorial Github
Gower, J.C., Lubbe, S. and le Roux, N.J. 2011 Understanding Biplots Wiley

BOOK CHAPTERS

Authors Year Title Pages Book Editors Publisher
Nienkemper-Swanepoel, J., le Roux, N.J. and Gardner-Lubbe, S. 2021 A Simulation Study for the Identification of Missing Data Mechanisms Using Visualisation 205-214 Data Analysis and Rationality in a Complex World Chadjipadelis, T., Lausen, B., Markos, A., Lee, T.R., Montanari, A. and Nugent, R. Springer

SCIENTIFIC JOURNALS

Authors Year Title Journal
Ganey, R. and Gardner-Lubbe, S. 2026 A Canonical Variate Analysis Biplot based on the Generalised Singular Value Decomposition Statistical Methods and Application, 23-Jan
Chambers, N., Heunis, T., Gardner-Lubbe, S., Capal, J.K., Bissell, S., Byars, A.W., Cukier, S., Davis, P.E., Flinn, J., Gipson, T.T., Kingswood, J.C., Kumm, A.J., Schoeters, E., Smith, C., Srivastava, S., Takei, M., Vanclooster, S., van Eeghen, A.M., Waltereit, R., Krueger, D.A. 2025 Validation of the self-report quantified Tuberous Sclerosis Complex-Associated Neuropsychiatric Disorders Checklist (TAND-SQ). Orphanet Journal of Rare Diseases, 20, 304
Claassen-Weitz, S., Xia, Y., Hannan, L., Gardner-Lubbe, S., Mwaikono, K.S., Mounaud, S.H., Nierman, W.C., Workman, L., Dube, F.S., Africa, S., Patel, F., Allen, V., Ah Tow Edries, L., Zar, H.J., Nicol, M.P. 2025 Nasopharyngeal microbiota in South African infants with lower respiratory tract infection: a nested case-control study of the Drakenstein Child Health Study Clinical Infectious Diseases, p.ciaf184
le Roux, N.J. and Gardner-Lubbe, S. 2025 A two-group canonical variate analysis biplot for an optimal display of both means and cases Advances in Data Analysis and Classification, 19, 721 - 748
Claassen-Weitz, S., du Toit, E., Gardner-Lubbe, S., Kullin, B., Bellairs, G., Hilton, H., Chicken, A., Welp, K., Livingstone, H., Brink, A. 2024 Knowledge and perceptions of South African blood donors towards biobanking and stool donation Southern African Journal of Infectious Diseases, 39, a645
Gardner-Lubbe, S. 2024 Bootstrapping Cluster Analysis Solutions with the R Package ClusBoot Austrian Journal of Statistics, 53, 19-Jan
Nienkemper-Swanepoel, J., le Roux, N.J. and Gardner-Lubbe, S. 2024 On subset multiple correspondence analysis for incomplete multivariate categorical data Communications in Statistics-Simulation and Computation, 53, 5229 - 5241
van der Westhuizen, S., Heuvelink, G.B., Gardner-Lubbe, S. and Clarke, C.E. 2024 Biplots for understanding machine learning predictions in digital soil mapping Ecological Informatics, 84, 102892
Abotsi, R.E., Dube, F.S., Rehman, A.M., Claassen-Weitz, S., Xia, Y., Simms, V., Mwaikono, K.S., Gardner-Lubbe, S., McHugh, G., Ngwira, L.G., Kwambana-Adams, B., Heyderman, R.S., Odland, J.O., Ferrand, R.A. and Nicol, M.P. 2023 Sputum bacterial load and bacterial composition correlate with lung function and are altered by long term azithromycin treatment in children with HIV-associated chronic lung disease Microbiome, 11, 29
Cornelissen, R.J., le Roux, N.J., Gardner-Lubbe, S., Aleixandre Tudo, J.L., Nieuwoudt, H.H 2023 Detection and Quantification of Grapevine Bunch Rot Using Functional Data Analysis and Canonical Variate Analysis Biplots of Infrared Spectral Data South African Journal of Enology and Viticulture, 44, 144 - 155
Heunis, T., Chambers, N., Vanclooster, S., Bissell, S., Byars, A.W., Capal, J.K., Cukier, S., Davis, P., de Vries, M.C., De Waele, L., Flinn, J., Gardner-Lubbe, S., Gipson, T., Kingswood, J.C., Krueger, D.A., Kumm, A.J., Sahin, M., Schoeters, E., Smith, C., Srivastava, S., Takei, M., van Eeghen, A.M., Waltereit, R., Jansen, A.C. and de Vries, P.J. 2023 Development and Feasibility of the Self-Report Quantified Tuberous Sclerosis Complex-Associated Neuropsychiatric Disorders Checklist (TAND-SQ) Pediatric Neurology, 147, 101-123
Nienkemper-Swanepoel, J., le Roux, N.J. and Gardner-Lubbe, S. 2023 GPAbin: unifying visualizations of multiple imputations for missing values Communications in Statistics - Simulation and Computation, 52, 2666 - 2685
Gower, J.C., le Roux, N.J. and Gardner-Lubbe, S. 2022 Properties of individual differences scaling and its interpretation Statistical Papers, 63, 1221 - 1245
Heunis, T., Bissell, S., Byars, A.W., Capal, J.K., Chambers, N., Cukier, S., Davis, P., De Waele, L., Flinn, J., Gardner-Lubbe, S., Gipson, T., Kingswood, J.C., Krueger, D.A., Kumm, A.J., Sahin, M., Schoeters, E., Smith, C., Srivastava, S., Takei, M., Vanclooster, S., van Eeghen, A.M., Waltereit, R., Jansen, A.C. and de Vries, P.J. 2022 Empowering Families Through Technology: A Mobile-Health Project to Reduce the TAND Identification and Treatment Gap (TANDem) Frontiers in Psychiatry, 13, 834628
Vanclooster, S., Bissell, S., van Eeghen, A.M., Chambers, N., De Waele, L., Byars, A.W., Capal, J.K., Cukier, S., Davis, P., Flinn, J., Gardner-Lubbe, S., Gipson, T., Heunis, T., Hook, D., Kingswood, J.C., Krueger, D.A., Kumm, A.J., Sahin, M., Schoeters, E., Smith, C., Srivastava, S., Takei, M., Waltereit, R., Jansen, A.C. and de Vries, P.J. 2022 The research landscape of tuberous sclerosis complex-associated neuropsychiatric disorders (TAND) - a comprehensive scoping review Journal of Neurodevelopmental Disorders, 14, 13
Gardner-Lubbe, S. Filzmoser, P. and Templ, M. 2021 Comparison of zero replacement strategies for compositional data with large numbers of zeros Chemometrics and Intelligent Laboratory Systems, 210, 104248
Rodwell, D.T., van der Merwe, C.J. and Gardner-Lubbe, S. 2021 Categorical CVA biplots Computational Statistics and Data Analysis, 163, 107299
de Vries, P.J, Leclezio, L., Gardner-Lubbe, S., Krueger, D., Sahin, M., Sparagana, S., De Waele, L. and Jansen, A. 2021 Multivariate data analysis identifies natural clusters of Tuberous Sclerosis Complex Associated Neuropsychiatric Disorders (TAND) Orphanet Journal of Rare Diseases, 16, 447
Claassen-Weitz, S., Gardner-Lubbe, S., Mwaikono, K.S. du Toit, E., Zar, H.J. and Nicol, M.P. 2020 Optimizing 16S rRNA gene profile analysis from low biomass nasopharyngeal and induced sputum specimens BMC Microbiology, 20, 26-Jan
Gardner-Lubbe, S 2020 Linear discriminant analysis for multiple functional data analysis Journal of Applied Statistics, 48, 1917-1933
Naude, P.J.W., Claassen-Weitz, S., Gardner-Lubbe, S., Botha, G. Kaba, M., Zar, H.J., Nicol, M.P. and Stein, D.J. 2020 Association of maternal prenatal psychological stressors and distress with maternal and early infant faecal bacterial profile Acta Neuropsychiatrica, 32, 32-42
Abdulgader, S.M., Robberts, L., Ramjith, J., Nduru, P.M., Dube, F., Gardner-Lubbe, S., Zar, H.J. and Nicol, M.P. 2019 Longitudinal Population Dynamics of Staphylococcus aureus in the Nasopharynx During the First Year of Life Frontiers in Genetics, 10, 198
Ojo-Okunola, A., Claassen-Weitz, S., Mwaikono, K.S., Gardner-Lubbe, S., Stein, D.J, Zar, H.J., Nicol, M.P. and du Toit E. 2019 Influence of Socio-Economic and Psychosocial Profiles on the Human Breast Milk Bacteriome of South African Women Nutrients, 11, 1390
Ojo-Okunola, A., Claassen-Weitz, S., Mwaikono, K.S., Gardner-Lubbe, S., Zar, H.J., Nicol, M.P. and du Toit, E. 2019 The Influence of DNA Extraction and Lipid Removal on Human Milk Bacterial Profiles Methods and Protocols, 3, 39
Brown, J.C., Gardner-Lubbe, S., Lambert, M.I., van Mechelen, W. and Verhagen, E. 2018 Coach-directed education is associated with injury-prevention behaviour in players: an ecological cross-sectional study British Journal of Sports Medicine, 15, 989-993
Claassen-Weitz, S., Gardner-Lubbe, S., Nicol, P., Botha, G., Mounaud, S., Shankar, J., Nierman, W.C., Mulder, N., Budree, S., Zar, H.J., Nicol, M.P and Kaba, M. 2018 HIV-exposure, early life feeding practices and delivery mode impacts on faecal bacterial profiles in a South African birth cohort Scientific reports, 8, 5078
Dube, F.S., Ramjith, J. Gardner-Lubbe, S., Nduru, P., Robberts, F.J.L., Wolter, N., Zar, H.J. and Nicol, M.P. 2018 Longitudinal characterization of nasopharyngeal colonization with Streptococcus pneumoniae in a South African birth cohort post 13-valent pneumococcal conjugate vaccine implementation Scientific reports, 8, 12497
Gower, J.C., Gardner-Lubbe, S. and le Roux, N.J. 2018 Interaction: Fisher’s Optimal Scores Revisited Journal of Agricultural, Biological, and Environmental Statistics, 23, 92-112
Leclezio, L., Gardner-Lubbe, S. and de Vries, P.J. 2018 Is It Feasible to Identify Natural Clusters of TSC-Associated Neuropsychiatric Disorders (TAND)? Pediatric Neurology, 81, 38-44
Nienkemper-Swanepoel, J., le Roux, N.J. and Gardner-Lubbe, S. 2018 Visualising Incomplete Data with Subset Multiple Correspondence Analysis Archives of Data Science, Series A, 5, 33
Gower, J.C.,Gardner-Lubbe, S. and le Roux, N.J. 2017 Data analysis: Good but … Statistica Applicata - Italian Journal of Applied Statistics, 29, 293-304
Williams, D. and Gardner-Lubbe, S. 2017 Visualising grouped three-way data Chemometrics and Intelligent Laboratory Systems, 167, 232-237
Dube, F.S., Kaba, M., Robberts, F.J.L., Tow, L.A., Gardner-Lubbe, S., Zar, H.J. and Nicol, M.P. 2016 Respiratory Microbes Present in the Nasopharynx of Children Hospitalised with Suspected Pulmonary Tuberculosis in Cape Town, South Africa BMC Infectious Diseases, 16
Gardner-Lubbe, S. 2016 A triplot for multiclass visualisation Computational Statistics and Data Analysis, 94, 20-32
Gower, J.C., le Roux, N.J. and Gardner-Lubbe, S. 2016 Biplots: qualitative data. WIREs Computational Statistics, 8, 82-111
Mulenga, C.N., Brouze, K. and Gardner-Lubbe, S. 2016 Student leadership training as a stress reduction strategy at a South African university South African Journal of Higher Education, 30, 141-156
Williams, D. and Gardner-Lubbe, S. 2016 Visualising three-way arrays Chemometrics and Intelligent Laboratory Systems, 158, 180-186
Zar, H.J., Barnett, W., Stadler, A., Gardner-Lubbe, S., Myer, L. & Nicol, M.P. 2016 Aetiology of childhood pneumonia in a well vaccinated South African birth cohort: a nested case-control study Lancet Respiratory Medicine, 4, 463-472
Brown, J.C., Gardner-Lubbe, S., Lambert, M.I., van Mechelen, W. and Verhagen, E. 2015 The BokSmart programme is associated with improvements in injury prevention behaviours of rugby union players: an ecological cross-sectional study Injury Prevention, 21, 173-178
Gardner-Lubbe, S. and Dube F. 2015 Visualisation of quadratic discriminant analysis and its application in exploration of microbial interactions BioData Mining, 8
Gower, J.C., le Roux, N.J. and Gardner-Lubbe, S. 2015 Biplots: quantitative data. WIREs Computational Statistics, 7, 42-62
Groenen, P.J.F., le Roux, N.J. and Gardner-Lubbe, S. 2015 Spline-based nonlinear biplots Advances in Data Analysis and Classification, 9, 219-238
Oyedele, O.F. and Gardner-Lubbe, S. 2015 The construction of a partial least-squares biplot Journal of Applied Statistics, 42, 2449-2460
Gower, J.C., le Roux, N.J. and Gardner-Lubbe, S. 2014 The Canonical Analysis of Distance Journal of Classification, 31, 107-128
Le Roux, N.J., Gardner-Lubbe, S. and Gower, J.C. 2014 The analysis of distance of grouped data with categorical variables: Categorical canonical variate analysis Journal of Multivariate Analysis, 132, 24-Sep
Schmutz, A.M.S., Gardner-Lubbe, S. and Archer, E. 2013 Clinical educators’ self-reported personal and professional development after completing a short course in undergraduate clinical supervision at Stellenbosch University African Journal of Health Professions Education, 5, 13-Aug
Van Heerden, A., le Roux, N.J., Swart, J., Rypstra, T., Gardner-Lubbe, S. and Botha, A. 2011 Chemical alterations induced by Pycnoporus sanguineus / Aspergillus flavipes co-cultures in wood from different tree species Wood Science and Technology, 45, 237-248
Du Plessis, M., le Roux, N.J., Gardner-Lubbe, S., Swart, J.P.J. and Rypstra, T. 2010 The pulp and paper properties of Sirex noctilio infested and fire damaged thermomechanically pulped South African Grown Pinus patula Southern Forests, 72, 173-179
Gardner-Lubbe, S, le Roux, NJ, Maunders, H, Shah, V and Patwardhan, S. 2009 Biplot methodology in exploratory analysis of microarray data Statistical Analysis and Data Mining, 2, 135-145
La Grange, A.M., le Roux, N.J., Gardner-Lubbe, S. 2009 BiplotGUI: Interactive Biplots in R Journal for Statistical Software, 30, 30-Jan
Scheepers, G.C., le Roux, N.J., Gardner, S. and Rypstra, T. 2009 Discolouration during kiln drying of South African Pinus elliottii. The Journal of the Institute of Wood Science, 19, 57-68
Du Plessis, M., le Roux, N.J., Gardner-Lubbe, S., Swart, J.P.J. and Rypstra, T. 2008 The effect of Sirex noctilio infestation and fire damage on the chemical composition of South African grown Pinus patula pulpwood Southern Forests, 70, 215-220
Gardner-Lubbe, S., le Roux, N.J. and Gower, J.C. 2008 Measures of Fit in Principal Component and Canonical Variate Analyses Journal of Applied Statistics, 35, 947-965
Van Heerden, A., le Roux, N.J., Swart, J., Gardner-Lubbe, S. and Botha, A. 2008 Assessment of wood degradation by Pycnoporus sanguineus when co-cultured with selected fungi World Journal of Microbiology and Biotechnology, 24, 2489-2497
Arnold, G., Gower, J.C., Gardner-Lubbe, S. and le Roux, N.J. 2007 Biplots of free-choice-profile data in Generalized Orthogonal Procrustes Analysis Journal of the Royal Statistical Society Series C Applied Statistics, 56, 445-458
Gardner, S., Gower, J.C. and le Roux, N.J. 2006 A Synthesis of Canonical Variate Analysis, Generalised Canonical Correlation and Procrustes Analysis Computational Statistics and Data Analysis, 50 (spe. iss.), 107-134
Le Roux, N.J. and Gardner, S. 2006 A biplot based approach to discriminant analysis with categorical variables in the presence of reversals The South African Statistical Journal, 40, 31-Jan
Gardner, S. and le Roux, N.J. 2005 Extensions of biplot methodology to discriminant analysis Journal of Classification, 22, 59-86
Gardner, S., le Roux, N.J., Rypstra, T. and Swart, J.P.J. 2005 Extending a scatterplot for displaying group structure in multivariate data ORiON: Journal of the Operations Research of South Africa, 22, 111-124
Gardner, S., le Roux, NJ and Aldrich C. 2005 Process Data Visualisation with Biplots Minerals Engineering, 18, 955-968
Le Roux, N.J. and Gardner, S. 2005 Analysing your multivariate data as a pictorial: A case for applying biplot methodology? International Statistical Review, 73, 365-387
Le Roux, N.J., Gardner, S. and Aldrich, C. 2005 Biplot analysis of process systems SAIEE Africa Research Journal, 96, 253-258
Wurz, S., van Peer, P., le Roux, N.J., Gardner, S. and Deacon, H.J. 2005 Continental patterns in stone tools: a technological and biplot-based comparison of early late pleistocene assemblages from northern and southern Africa African Archaeological Review, 22, 24-Jan
Aldrich, C., Gardner, S. & le Roux, N.J. 2004 Monitoring of metallurgical process plants by using biplots AIChE Journal, 50, 2167-2186
Erasmus, P.D., Lambrechts, I.J., le Roux, N.J. and Gardner, S. 2003 The evaluation of traditional and value-added measures of capital intensity Management Dynamics: Contemporary research, 12, 23-Dec
Le Roux, N.J., Gardner, S. and Olivier, P. 2003 Biplots for displaying financial performance graphically SA Journal of Accounting Research, 17, 41-64
Wurz, S., le Roux, N.J., Gardner, S. and Deacon, H.J. 2003 Discriminating between the end products of the earlier Middle Stone Age sub-stages at Klasies River using biplot methodology Journal of Archaeological Science, 30, 1107-1126
Burden, M., Gardner, S., le Roux, N.J. and Swart, J.P.J. 2001 Ou-Kaapse meubels en stinkhoutidentifikasie: Moontlikhede met kanoniese veranderlike-analise en bistippings SA Tydskrif vir Kultuurgeskiedenis, 15, 50-73
Erasmus P.D., Lambrechts, I.J., le Roux, N.J. and Gardner, S. 2001 The use of biplots to interpret multivariate data: Measuring capital intensity Management Dynamics: Contemporary research, 10, 48-73
Gardner, S., Baard, E.H.W. and le Roux N.J. 1999 Estimating the Detection Probability of Psammobates geometricus South-African Journal of Wildlife Research, 29, 62-71

CONFERENCE PROCEEDINGS

Authors Year Title Editors Volume
Nienkemper-Swanepoel, J., le Roux, N.J. and Gardner-Lubbe, S. 2019 GPAbin for data visualization in the presence of missing observations Egozcue, J.J., Graffelman, J. and Ortego, M.I. Proceedings of the 8th International Workshop on Compositional Data Analysis,91-97
Pierre Bernard, T. and Lubbe, S. 2015 A graphical overview of social inequality in South Africa Proceedings of the ISI World Statistics Congress
Oyedele, O.V.F. and Lubbe, S. 2013 The Construction of a Partial Least Squares Biplot Proceedings of the ISI World Statistics Congress,4165-4170
Timm, A. and Gardner-Lubbe, S. 2013 The MDS-GUI: A Graphical User Interface for Comprehensive Multidimensional Scaling Applications Proceedings of the ISI World Statistics Congress,4159-4164
Gardner, S. and le Roux, N.J. 2006 Multidimensional visualisation of time series and the construction of acceptance regions in a PCA biplot Rizzi, A and Vichi, M Proceedings in Computational Statistics, Physica-Verlag: Heidelberg,829-836
Gardner, S. and le Roux, N.J. 2006 Sub-species of Homopus Areolatus? Biplots and small class inference with Analysis of Distance Batagelj, V, Bock, HH, Ferligoj, A and Ziberna, A Data Science and Classification, Springer-Verlag: Berlin,221-228
Gardner, S. and le Roux, N.J. 2005 An identification biplot for detecting forgery Proceedings of the ISI World Statistics Congress
Gardner, S. and le Roux, N.J. 2004 Modified biplots for enhancing two-class discriminant analysis Banks, D, House, L, McMorris, FR, Arabie, P and Gaul, W Classification, clustering and data mining applications, Springer: New York,233-240
Gardner, S. and le Roux, N.J. 2003 Discriminant analysis of categorical variables: a biplot based approach Schader M, Gaul W and Vichi M Between data science and applied data analysis, Springer: Berlin,30-38
Gardner, S. and le Roux, N.J. 2003 Graphics and visualisation in practice: Biplots for exploring multidimensional reality Bulletin of the of the ISI Biennial Session Vol LX, Book 1,270-273
Gardner, S., le Roux, N.J. and Aldrich C. 2003 Visualisation of Process Data with Biplots AFCON2003
Gardner, S. and le Roux, N.J. 2002 Biplot methodology for discriminant analysis based upon robust methods and principal curves Jajuga, K, Sokolowski, A and Bock, H-H Data analysis and classification, Springer-Verlag: Berlin,169-176
Erasmus, P.D., Lambrechts, I.J., le Roux, N.J. and Gardner, S. 2001 Measuring the capital intensity of enterprises listed in the industrial sector of the Johannesburg Stock Exchange: The use of value added measures
Erasmus, P.D., Lambrechts, I.J., le Roux, N.J. and Gardner, S. 2000 Determining a method to measure capital intensity for enterprises listed in the Industrial sector of the Johannesburg Stock Exchange for the period 1989 to 1996 Bonnet, MPB, Olink, H and Spekle, RF FMA-kroniek 2000,275-295

SOFTWARE

BiplotGUI.

MDSGUI.

ClusBoot.

biplotEZ.

CONFERENCE PRESENTATIONS

Authors Title Conference
Lubbe, S. and Brito, P. Symbolic Data Analysis and Visualisation with Principal Component Analysis Biplots SASA: 66th Annual conference of the South African Statistical Association, 24 – 28 November 2025, Vanderbijlpark, South Africa
Masoumifard, K. van der Westhuizen, S. and Lubbe, S. Random Forest Models for Compositional Data SASA: 66th Annual conference of the South African Statistical Association, 24 – 28 November 2025, Vanderbijlpark, South Africa
Sebatjane, P., Lubbe, S. and le Roux, N.J. Calibration of compositional biplot axes SASA: 66th Annual conference of the South African Statistical Association, 24 – 28 November 2025, Vanderbijlpark, South Africa
Lubbe, S. and Brito, P. Principal Component Analysis Biplots for Interval Scaled Data IX Latin American Conference on Statistical Computing LACSC 2025, 4 – 7 November 2025, Valparaíso, Chile
Masoumifard, K., van der Westhuizen, S. and Lubbe, S. Dirichlet-Random Forest for Predicting Compositional Data DSSV: Data Science, Statistics and Visualisation, 7 – 9 July 2025, Kruger National Park, South Africa
Sebatjane, P., Lubbe, S. and le Roux, N.J. Visualisation of Compositional Data Using Biplots DSSV: Data Science, Statistics and Visualisation, 7 – 9 July 2025, Kruger National Park, South Africa
Lubbe, S. A Collection of Biplots for Classification International Association of Statistical Computing Asian Regional Section Conference, 8 – 14 December 2024, Taipei, Taiwan
Buys, R., Sandilands, D., Lubbe, S. and van der Merwe, C. bipl5: An R package for reactive calibrated axes biplots SASA: 65th Annual conference of the South African Statistical Association, 18 - 22 November 2024, Stellenbosch
Lubbe, S. Timeseries PCA biplots SASA: 65th Annual conference of the South African Statistical Association, 18 - 22 November 2024, Stellenbosch
Sebatjane, P., Lubbe, S. and le Roux, N.J. Compositional biplot approaches SASA: 65th Annual conference of the South African Statistical Association, 18 - 22 November 2024, Stellenbosch
Ganey, R. and Lubbe, S. A Canonical Variate Analysis Biplot based on the Generalised Singular Value Decomposition ICORS meets DSSV 2024, 29 July - 1 August 2024, Washington, USA
Lubbe, S. A Collection of Biplots for Classification IFCS: Conference of the International Federation of Classification Society, 15 – 19 July 2024, San Jose, Costa Rica
Ganey, R and Lubbe, S. A Canonical Variate Analysis Biplot based on the Generalized Singular Value Decomposition SASA: 64th Annual conference of the South African Statistical Association, 29 November – 1 December 2023, Durban, South Africa
Lubbe, S., le Roux, N.J., Nienkemper-Swanepoel, J., Ganey, R., Adams, Z. and Buys, R. BiplotEZ R package for EZier biplots SASA: 64th Annual conference of the South African Statistical Association, 29 November – 1 December 2023, Durban, South Africa
Manefeldt, P.C., Lamont, M. and Lubbe, S. Extending Random Forest Biplots through Manifold Exploration SASA: 64th Annual conference of the South African Statistical Association, 29 November – 1 December 2023, Durban, South Africa
Nienkemper-Swanepoel, J., le Roux, N. and Lubbe, S. GPAbin MCA biplots to recover categorical response patterns after multiple imputation SASA: 64th Annual conference of the South African Statistical Association, 29 November – 1 December 2023, Durban, South Africa
Sebatjane, P., Lubbe, S. and le Roux, N.J. Visualization of compositional data SASA: 64th Annual conference of the South African Statistical Association, 29 November – 1 December 2023, Durban, South Africa
van der Westhuizen, S., Heuvelink, G. and Lubbe, S. Biplots for understanding machine learning predictions in digital soil mapping SASA: 64th Annual conference of the South African Statistical Association, 29 November – 1 December 2023, Durban, South Africa
Lubbe, S. Multi-dimensional Visualisations with biplotEZ Southern Africa Mathematical Sciences Association conference, 21 – 24 November 2023, Pretoria, South Africa
Lubbe, S. the BIplot Zone for Exploring Truths in mixed scaled measurements CARME: Correspondence Analysis and Related Methods, 26 – 29 September 2023, Bonn, Germany
Ganey, R. and Lubbe, S. High-dimensional LDA biplot through the GSVD: A case where p > N COMPSTAT2023, 22-25 August 2023, London, UK
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Investigation into the impact of (un)congenial multiple imputation approaches on GPAbin biplots COMPSTAT2023, 22-25 August 2023, London, UK
Le Roux, N.J. and Lubbe, S. Predictive biplots for individual differences scaling (INDSCAL) models DSSV: Data Science, Statistics and Visualisation Conference, 5 – 7 July 2023, University of Antwerpen
Manefeldt, P., Lamont, M. and Lubbe, S. Visualising interpretability of random forest models DSSV: Data Science, Statistics and Visualisation Conference, 5 – 7 July 2023, University of Antwerpen
Adams, Z., Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Exploring sentiment contained in COVID-19 related Tweets with embedded word MCA biplots SASA: 63rd Annual conference of the South African Statistical Association, 30 November - 2 December 2022, George
Lubbe, S. and le Roux, N.J. Biplots for individual differences scaling models SASA: 63rd Annual conference of the South African Statistical Association, 30 November - 2 December 2022, George
Lubbe, S. Visualising and exploring multi-dimensional sensory data Sensometrics conference, 15 – 17 November 2022, online
Mostert, A.G., Coetzer, R.L.J. and Lubbe, S. Variable contributions based on pairwise PCA 18th International Conference of Computational Methods in Sciences and Engineering, 26-29 October 2022. Heraklion, Crete, Greece
Nienkemper-Swanepoel​, J., le Roux, N.J. and Lubbe, S. Sensitivity analysis of the choice of multiple imputation approach on categorical GPAbin biplots COMPSTAT2022: 24th International Conference on Computational Statistics, 23 - 26 August 2022, University of Bologna, Italy
Adams, Z., Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Embedded word MCA biplots for sentiment visualisation: Application to COVID-19 related Tweets IFCS: 17th Conference of the International Federation of Classification Societies, 19 - 23 July 2022, Porto, Portugal
Nienkemper-Swanepoel, N.J., Lubbe, S. and le Roux, N.J. Extending GPAbin to visualise missing multivariate continuous data SASA: 62nd Annual Conference of the South African Statistical Association, 1 – 3 December 2021, Stellenbosch
Van der Merwe, C.J., Sandilands, D. and Lubbe, S. Exploding biplots with density axes in Plotly SASA: 62nd Annual Conference of the South African Statistical Association, 1 – 3 December 2021, Stellenbosch
Lubbe, S., le Roux, N.J. Nienkemper, J. and van der Merwe, C.J. Correspondence analysis and related biplot visualisation to aid analyses of categorical data containing missing values WSC: 63rd World Statistics Congress, 11 – 16 July 2021, online
Lubbe, S. and Filzmoser, P.J. Comparison of Zero Replacement Strategies for Compositional Data with Large Numbers of Zeros DSSV: Data Science, Statistics and Visualisation Conference, 29 – 31 July 2020, online
Lubbe, S. and le Roux, N.J. Analysis and Visualisation of spectroscopy data DSSV: Data Science, Statistics and Visualisation Conference, 29 – 31 July 2020, online
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Missing data: GPAbin biplots DSSV: Data Science, Statistics and Visualisation Conference, 29 – 31 July 2020, online
Lubbe, S., Daniels, A.. Opara, L., Niewoudt, H. and le Roux N.J. A novel application of survival and competing risk models in agriculture SASA: 61st Annual Conference of the South African Statistical Association, 25 – 29 November 2019. Port Elizabeth
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Extended applications of GPAbin biplots SASA: 61st Annual Conference of the South African Statistical Association, 25 – 29 November 2019. Port Elizabeth
Ganey, R. and Lubbe, S. Visualising multivariate data in a principal surface biplot IFCS: 16th biennial conference of the International Federation of Classification Societies, 26 – 29 August 2019, Thessaloniki, Greece
Le Roux, N.J., Gower, J.C. and Lubbe, S. Properties of individual differences scaling and its interpretation IFCS: 16th biennial conference of the International Federation of Classification Societies, 26 – 29 August 2019, Thessaloniki, Greece
Lubbe, S. Functional linear discriminant analysis for several functions and more than two groups IFCS: 16th biennial conference of the International Federation of Classification Societies, 26 – 29 August 2019, Thessaloniki, Greece
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. A simulation study for the identification of missing data mechanisms using visualisations IFCS: 16th biennial conference of the International Federation of Classification Societies, 26 – 29 August 2019, Thessaloniki, Greece
Le Roux, N.J. Nienkemper-Swanepoel, J. and Lubbe, S. GPAbin for data visualization in the presence of missing observations CoDaWork 2019, 3 – 8 June 2019, Terrassa, Spain
Ganey, R. and Lubbe, S Applications of the principal surface biplot CARME: Correspondence Analysis and Related Methods Conference, 4 – 6 February 2019, Stellenbosch
Nienkemper-Swanepoel, J. le Roux, N.J. and Lubbe, S. To impute or not to impute categorical data: application of multiple correspondence analysis CARME: Correspondence Analysis and Related Methods Conference, 4 – 6 February 2019, Stellenbosch
Rowan, A. and Lubbe, S. Unravelling black box machine learning technique predictions using biplots CARME: Correspondence Analysis and Related Methods Conference, 4 – 6 February 2019, Stellenbosch
Lubbe, S. Comparison of Unfolding and Correspondence Analysis SASA: Annual South African Statistical Association Conference, 26 – 29 November 2018, Johannesburg
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Visualisations for identifying missing data mechanisms SASA: Annual South African Statistical Association Conference, 26 – 29 November 2018, Johannesburg
Lubbe, S. A naïve visualisation of Data Science COMPSTAT2018, 28-31 August 2018, Iaşi, Romania
Lubbe, S. Visualisation as a tool to understand the sights and sounds of data Conference BRICS on Mathematics, 23 – 27 July 2018, Foz do Iguaçu, Brazil
Ganey, R. and Lubbe, S. A Visualizing Multivariate data using Principal Surfaces Biplots DSSV: Data Science, Statistics and Visualisation conference, 9 – 11 July 2018, Vienna, Austria
Le Roux, N.J., Gower, J.C. and Lubbe, S. Can within-group information be used to supplement visual representations of two or three group Canonical Variate Analyses DSSV: Data Science, Statistics and Visualisation conference, 9 – 11 July 2018, Vienna, Austria
Ganey, R. and Lubbe, S. A Biplot based on a Principal Surface 5th European Conference on Data Analysis, 4 – 6 July 2018, Paderborn, Germany
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Visualising incomplete data with subset Multiple Correspondence Analysis 5th European Conference on Data Analysis, 4 – 6 July 2018, Paderborn, Germany
Rowen, A., Lubbe, S, le Roux, N.J. and Schoonees, P. Unravelling black box machine learning technique predictions using biplots 5th European Conference on Data Analysis, 4 – 6 July 2018, Paderborn, Germany
Le Roux, N.J., Gower, J.C. and Lubbe, S. Biplot visualisations of interactions in a bilinear model having a qualitative depended variable SASA: Annual South African Statistical Association Conference, 27 – 30 November 2017, Bloemfontein
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Competing approaches to the visualisation of incomplete categorical data sets SASA: Annual South African Statistical Association Conference, 27 – 30 November 2017, Bloemfontein
Ganey, R. and Lubbe, S. Biplots based on Principal Surfaces IFCS: International Federation of Classification Societies Conference, 8 – 10 August 2017, Tokyo, Japan
Lubbe, S. A comparison of different applications of functional linear discriminant analysis IFCS: International Federation of Classification Societies Conference, 8 – 10 August 2017, Tokyo, Japan
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Challenges in visualising and imputing missing categorical data IFCS: International Federation of Classification Societies Conference, 8 – 10 August 2017, Tokyo, Japan
Lubbe, S., Nicol, M.P. and Zar, H.J. Functional Discriminant Analysis for Multivariate Longitudinal Data WSC: World Statistics Congress, 16 – 21 July 2017, Marrakesh, Morocco
Lubbe, S. Visualisations associated with bootstrapping cluster analysis DSSV: Data Science, Statistics and Visualisation conference, 12 – 14 July 2017, Lisbon, Portugal
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. The virtues and pitfalls of the visualisation of incomplete categorical data DSSV: Data Science, Statistics and Visualisation conference, 12 – 14 July 2017, Lisbon, Portugal
Ganey, R. and Lubbe, S. Poster: Principal surfaces SASA: Annual South African Statistical Association Conference, 29 November – 1 December 2016, Cape Town
Joselson, N. and Lubbe, S. Poster: Uses of Principal Components in Generalized Linear Modeling SASA: Annual South African Statistical Association Conference, 29 November – 1 December 2016, Cape Town
Lubbe, S., Leclezio, L. and de Vries, P. Multivariate analysis to find natural clusters of Tuberous Sclerosis Complex Associated Neuropsychiatric Disorders SASA: Annual South African Statistical Association Conference, 29 November – 1 December 2016, Cape Town
Mostert, A., Coetzer, R. and Lubbe, S. Evaluation of fault diagnosis techniques in multivariate statistical process control SASA: Annual South African Statistical Association Conference, 29 November – 1 December 2016, Cape Town
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Multidimensional graphical comparisons of imputation methods for missing values in categorical data sets SASA: Annual South African Statistical Association Conference, 29 November – 1 December 2016, Cape Town
Le Roux, N.J., Lubbe, S. and Gower, J.C. Consequences of combining Fisher Optimal Scores with bi-additive models COMPSTAT2016, 23- 26 August 2016, Oviedo, Spain
Nienkemper-Swanepoel, J., le Roux, N.J. and Lubbe, S. Visualisations of multiple imputations using Generalized Orthogonal Procrustes Analysis COMPSTAT2016, 23- 26 August 2016, Oviedo, Spain
Lubbe, S., Claassen, S., du Toit, E., Botha, G., Lennard, K., Zar, H.J. and Nicol, M.P. A longitudinal log ratio biplot based on functional data analysis modelling International Conference on Information Complexity and Statistical Modeling in High Dimensions with Applications, 18 – 21 May 2016, Nevshir, Turkey
Lubbe, S., le Roux, N.J. and Gower, J.C. Fisher Optimal Scores for visualization in categorical data SASA: Annual South African Statistical Association Conference, 30 November – 3 December 2015, Pretoria
Nienkemper-Swanepoel, J., le Roux, N.J., Lubbe, S. and von Maltiz, M.J. Generalized Orthogonal Procrustes Analysis for the comparison of Multiple Imputed data sets SASA: Annual South African Statistical Association Conference, 30 November – 3 December 2015, Pretoria
Claassen, S., du Toit, E., Botha, G., Lubbe, S., Zar, H.J. and Nicol, M.P. Poster: Dynamics of the nasopharyngeal microbiome preceding and at the onset of pneumonia in infants: a pilot study H3Africa Conference, 29 September 2015, Washington D.C.
Gower, J.C., le Roux, N.J. and Lubbe, S. Fisher Optimal Scores revisited CARME: Correspondence Analysis and Related Methods Conference, 21 – 23 September 2015, Naples, Italy
Lubbe, S. Including Covariates in Linear discriminant analysis CARME: Correspondence Analysis and Related Methods Conference, 21 – 23 September 2015, Naples, Italy
Pierre Bernard, T.C. and Lubbe, S. A graphical overview of social inequality in South Africa WSC: 60th ISI World Statistics Congress, 26-31 July 2015, Rio de Jeneiro, Brazil
Lubbe, S., Dube, F.S., Nicol, M.P. and Zar, H.J. Functional Data Analysis for the Investigation of Longitudinal Response Patterns in Health Care IFCS: Conference of the International Federation of Classification Societies, 6-8 July 2015, Bologna, Italy
Nienkemper-Swanepoel, J, Lubbe, S., le Roux, N.J. Smith, E., Zar, H.J. and Nicol, M.P. Biplot-based visualisations to explore relationships between pneumonia and nasopharyngeal pathogens IFCS: Conference of the International Federation of Classification Societies, 6-8 July 2015, Bologna, Italy
Lubbe, S. and Williams, D. Visualising three-way arrays: An outer product rank perspective Three-way methods In Chemistry And Psychology Conference, 31 May – 5 June 2015, Val di Zoldo, Belluno, Italy
Lubbe, S. and Essomba, R.F. Comparison of Basis Function Selection and Model Fitting for Functional Regression Models SASA: Annual South African Statistical Association Conference, 4-6 November 2014, Grahamstown
Lubbe, S. A Quadratic Discriminant Analysis Biplot COMPSTAT 2014, 18-22 August 2014, Genève, Switzerland
Brown, J.C., Lubbe, S., Lambert, M., van Mechelen, W. and Verhagen, E. Poster: The association between knowledge, perceptions, education and injury-preventing behaviour in rubgy union players IOC World Conference Prevention of Injury and Illness in Sport, 10-12 April 2014, Monaco
Dube, F.S., Kaba, M., Ah Tow, L., Africa, S., Lubbe, S., Zar, H.J. and Nicol, M.P. Poster: Microbiology of the Nasopharynx in Children Hospitalized with Suspected Pulmonary Tuberculosis 16th International Congress on Infectious Diseases, 2-5 April 2014, Cape Town
Essomba, R.F. and Lubbe, S. Applications of Functional Data Analysis SASA: Annual South African Statistical Association Conference, 6-8 November 2013, Polokwane
Le Roux, N.J., Lubbe, S. and Gower, J.C. The Analysis of Distance of Grouped Data with Categorical Variables: Categorical Canonical Variate Analysis Biplots SASA: Annual South African Statistical Association Conference, 6-8 November 2013, Polokwane
Lubbe, S. Application of Genetic Algorithms to Unidimensional Scaling SASA: Annual South African Statistical Association Conference, 6-8 November 2013, Polokwane
Oyedele, O.V.F. and Lubbe, S. Poster: Partial Least Squares Biplots for Generalised Linear Models SASA: Annual South African Statistical Association Conference, 6-8 November 2013, Polokwane
Pierre Bernard, T. and Lubbe, S. South African Household Survey Data: An Unbiased View on Narrowing the Gap Between Racial Groups SASA: Annual South African Statistical Association Conference, 6-8 November 2013, Polokwane
Oyedele O.V.F. and Lubbe S. The Construction of a Partial Least Squares Biplot WSC: 59th ISI World Statistics Congress, 25-30 August 2013, Hong Kong, China
Timm, A. and Gardner-Lubbe S. The MDS-GUI: A Graphical User Interface for Comprehensive Multidimensional Scaling Applications WSC: 59th ISI World Statistics Congress, 25-30 August 2013, Hong Kong, China
Williams, D. and Lubbe, S. Common Components to Construct Biplots for Longitudinal Data WSC: 59th ISI World Statistics Congress, 25-30 August 2013, Hong Kong, China
Oyedele, O.V.F. and Lubbe, S. PLS biplots: Another graphical tool for multivariate data IFCS: Conference of the International Federation of Classification Societies, 15-17 July 2013, Tilburg, The Netherlands
Le Roux, N.J., Lubbe, S. and Gower, J.C. Biplots constructed from Distance matrices SASA: Annual South African Statistical Association Conference, 7-9 November 2012, Port Elizabeth
Lubbe, S. and Timm, A. The MDS-GUI: A graphical user interface for comprehensive multidimensional scaling applications SASA: Annual South African Statistical Association Conference, 7-9 November 2012, Port Elizabeth
Oyedele, O.V.F., Lubbe, S. and le Roux, N.J. Partial Least Squares Regression Biplots SASA: Annual South African Statistical Association Conference, 7-9 November 2012, Port Elizabeth
Pierre Bernard, T. and Lubbe, S. Biplots for Investigating Differential Living Conditions between South African Racial Groups SASA: Annual South African Statistical Association Conference, 7-9 November 2012, Port Elizabeth
Williams, D. and Lubbe, S. Common Components to Construct Biplots for Longitudinal Data SASA: Annual South African Statistical Association Conference, 7-9 November 2012, Port Elizabeth
Gower, J.C., le Roux, N.J. and Lubbe, S. Biplots: The Palette COMPSTAT 2012, 27-31 August 2012, Limmasol, Cyprus
Le Roux, N.J., Gower, J.C. and Lubbe, S. Extending the Theory of Nonlinear Biplots: Categorical Canonical Variate Analysis Biplots COMPSTAT 2012, 27-31 August 2012, Limmasol, Cyprus
Lubbe, S., Oyedele, O.V.F. and le Roux, N.J. Biplots for Partial Least Squares Regression COMPSTAT 2012, 27-31 August 2012, Limmasol, Cyprus
Lubbe, S., le Roux, N.J. and Gower, J.C. Canonical Analysis of Distance in the Mining Industry SASA: Annual South African Statistical Association Conference, 1-3 November 2011, Pretoria
Oyedele, O.V.F. and Lubbe, S. The Covariance Biplot to reveal relationships between different sets of variables SASA: Annual South African Statistical Association Conference, 1-3 November 2011, Pretoria
Timm, A. and Lubbe, S. Programming in R: Exploring Classes, Methods and Interfacing SASA: Annual South African Statistical Association Conference, 1-3 November 2011, Pretoria
Williams, D. and Lubbe, S. Biplots for three-mode data: An application to HIV immune response data SASA: Annual South African Statistical Association Conference, 1-3 November 2011, Pretoria
Le Roux, N.J., Lubbe, S. and Gower, J.C. Biplots for Categorical Variables: Grouped and Ungrouped Data CARME: Correspondence Analysis and Related Methods Conference, 1-4 October 2011, Assos, Turkey
Lubbe, S., le Roux, N.J. and Gower, J.C. Analysis of Distance Biplots: Grouped and Ungrouped Data CARME: Correspondence Analysis and Related Methods Conference, 1-4 October 2011, Assos, Turkey
Lubbe, S., Silal, S. and le Roux, N.J. Constructing a Socio-Economic Status Index for a Non-Homogeneous Society with Distinct Sets of Variables in Multiple Correspondence Analysis CARME: International Conference on Correspondence Analysis and Related Methods, 8 – 11 February 2011, Rennes, France
Le Roux, N.J. and Lubbe, S. A biplot view of crime in the RSA SASA: Annual South African Statistical Association Conference, 10 - 12 November 2010, Potchefstroom
Lubbe, S. and Witten, G. Monoplot Analysis of Hedge Funds SASA: Annual South African Statistical Association Conference, 10 - 12 November 2010, Potchefstroom
Le Roux, N.J. and Lubbe, S. From Biplots to Understanding Biplots Gowerfest II: Geometry of Data Analysis. 19 July 2010, Milton Keynes, UK
Le Roux, N.J., Lubbe, S. and Aldrich, C. Advanced Biplot Diagnostics for Process Performance Evaluation SASA: South African Chemical Engineering Conference, 20 – 23 September 2009, Somerset West
Le Roux, N.J. and Lubbe, S. Biplots and Clustering for High-Dimensional Paired Data IFCS: The 11th Conference of the International Federation of Classification Societies, 15 – 18 March 2009, Dresden, Germany
Le Roux, N.J. and Lubbe, S. Optimal Canonical Variate Analysis Biplots when the number of groups is less than the number of variables SASA: Annual South African Statistical Association Conference, 29 – 31 October 2008, Pretoria
Lubbe, S., le Roux, N.J. and Cillie, R. A biplot view on Socio-economic progress in South Africa 1994 – 2006 SASA: Annual South African Statistical Association Conference, 29 – 31 October 2008, Pretoria
La Grange, A.M., le Roux, N.J. and Lubbe, S. Constructing and interacting with biplots: The BiplotGUI package for R RC33 : 7th International Conference on Social Science Methodology, 1–5 September 2008, Naples, Italy
Lubbe, S. and le Roux, N.J. Biplots, bagplots a-bags and more … RC33 : 7th International Conference on Social Science Methodology, 1–5 September 2008, Naples, Italy
Lubbe, S. and le Roux, N.J. Enhancing Multivariate Analyses in Forestry and Biopulping Applications with Biplot Methodology Conference of the International Biometrics Society, 13 –18 July 2008, Dublin, Ireland
Le Roux, N.J. and Lubbe, S. Geometrical considerations and Biplots associated with Canonical Variate Analysis involving two classes International Conference on Multivariate Statistical Modeling and High Dimensional Data Mining, 19–23 June 2008, Kayseri, Turkey
La Grange, A.M., le Roux, N.J. and Lubbe, S. BiplotGUI: An Interactive Menu-driven Package for Biplots in R SASA: Annual South African Statistical Association Conference, 31 October – 2 November 2007, Johannesburg
Le Roux, N.J., Lubbe, S, la Grange, AM and Groenen, PJF. General method for obtaining smoothed non-linear biplot prediction trajectories SASA: Annual South African Statistical Association Conference, 31 October – 2 November 2007, Johannesburg
Lubbe, S., le Roux, N.J., Gower, J.C., Maunders, H. and Patwardhan, S. Measures of Fit for Biplots: An Application in the Identification of Differentially Expressed Genes SASA: Annual South African Statistical Association Conference, 31 October – 2 November 2007, Johannesburg
Groenen, P.J.F., Lubbe, S., le Roux, N.J., la Grange, A.M. Nonlinear Biplots with a Shortest Distance Interpretation International Meeting of the Psychometric Society, 10 – 13 July 2007, Tokyo, Japan
La Grange, A.M., Lubbe, S., Groenen, P.J.F. and le Roux, N.J. Applying Unfolding in the Construction of Non-linear Biplot Trajectories IFCS: International Conference on Correspondence Analysis and Related Methods, 25 – 27 June 2007, Rotterdam, The Netherlands
Gardner, S. and le Roux, N.J. Biplots in the exploratory analysis of gene expression arrays SASA: Annual South African Statistical Association Conference, 1 – 3 November 2006, Stellenbosch
Le Roux, N.J. and Gardner, S. Statistical analysis of South African wood pulp data using biplots SASA: Annual South African Statistical Association Conference, 1 – 3 November 2006, Stellenbosch
Gardner, S. and le Roux, N.J. Multidimensional visualisation of time series and the construction of acceptance regions in a PCA biplot COMPSTAT 2006, 28 August – 1 September 2006, Rome, Italy
Gardner, S. and le Roux, N.J. Sub-species of Homopus Areolatus? Biplots and small class inference with Analysis of Distance IFCS: The 10th Conference of the International Federation of Classification Societies, 25 – 29 July 2006, Ljubljana, Slovenia
Gardner, S., le Roux, N.J. and Gower, J.C. Biplots for Free Choice Profile data in Generalised Orthogonal Procrustes Analysis SASA: Annual South African Statistical Association Conference, 2 – 4 November 2005, Grahamstown
Le Roux, N.J. and Gardner, S. Extensions of biplot methodology for analysing group structure in multivariate data SASA: Annual South African Statistical Association Conference, 2 – 4 November 2005, Grahamstown
Gardner, S. and le Roux, N.J. An Identification Biplot for detecting Forgery WSC: The 55th Session of the International Statistical Institute, 5–12 April 2005, Sydney, Australia
Gardner, S. and le Roux, N.J. An Application of Iterative Estimation of Effects in an Experimental Design and Linear Modelling Context SASA: Annual South African Statistical Association Conference, 3 – 5 November 2004, Bloemfontein
Le Roux, N.J., Gardner, S. and Gower, J.C. Using Procrustes Analysis for a Synthesis of Canonical Variate Analysis and Generalised Canonical Correlation Analysis SASA: Annual South African Statistical Association Conference, 3 – 5 November 2004, Bloemfontein
Gardner, S. and le Roux, N.J. Modified biplots for enhancing two-class discriminant analysis IFCSL The 9th Conference of the International Federation of Classification Societies, 15–18 July 2004, Chicago, USA
Gardner, S., le Roux, N.J. and Aldrich, C. Visualisation of process data with biplots First African Control Conference, 3–5 December 2003, Cape Town
Gardner, S. and le Roux, N.J. Application of biplotology in the two-class discriminant analysis case SASA: Annual South African Statistical Association Conference, 5–7 November 2003, Johannesburg
Le Roux, N.J. and Gardner, S. Biplotology for comparing archaeological artefacts from different sites SASA: Annual South African Statistical Association Conference, 5–7 November 2003, Johannesburg
Gardner, S. and le Roux, N.J. Graphics and visualisation in practice: Biplots for exploring multidimensional reality WSC: The 54th Session of the International Statistical Institute, 13–20 August 2003, Berlin, Germany
Gardner, S. and le Roux, N.J. Biplot methodology for categorical data CARME: International Conference on Correspondence Analysis and Related Methods, 30 June – 2 July 2003, Barcelona, Spain
Gardner, S. and le Roux, N.J. Applying robust techniques in biplot methodology SASA: Annual South African Statistical Association Conference, 6–8 November 2002, Pretoria
Le Roux, N.J. and Gardner, S. Discriminant analysis with binary variables: Biplots and the ‘reversal problem’ SASA: Annual South African Statistical Association Conference, 6–8 November 2002, Pretoria
Gardner, S. and le Roux, N.J. Biplot methodology in discriminant analysis with categorical variables The 26th Annual Conference of the Gesellschaft für Klassifikation, 22–24 July 2002, Mannheim, Germany
Gardner, S. and le Roux, N.J. Biplot methodology for discriminant analysis based upon robust methods and principal curves IFCS: The 8th Conference of the International Federation of Classification Societies, 16–19 July 2002, Kraków, Poland
Erasmus, P.D., Lambrechts, I.J., le Roux, N.J. and Gardner, S. Measuring the capital intensity of enterprises listed in the industrial sector of the Johannesburg Stock Exchange: The use of value-added measures Tenth annual SAFA conference, 2001, University of Cape Town Graduate School of Business, Cape Town
Erasmus, P.D., Lambrechts, I.J., le Roux, N.J. and Gardner, S. The use of principal component analyses and biplots to interpret multivariate data: Evaluating traditional and value added measures of capital intensity The 29th meeting of EURO Working Group on Financial Modelling, 2001, Haarlem, The Netherlands
Gardner, S. and le Roux, N.J. Representing large multi-dimensional data sets: Biplots, bagplots and alpha-bags. SASA: Annual South African Statistical Association Conference, 14–16 November 2001, Goudini
Le Roux, N.J. and Gardner, S. Principal components and biplots in allometry: Determining subspecies in Homopus Areolatus SASA: Annual South African Statistical Association Conference, 14–16 November 2001, Goudini
Erasmus, P.D., Lambrechts, I.J., le Roux, N.J. and Gardner, S. Determining a method to measure capital intensity for enterprises listed in the Industrial sector of the Johannesburg Stock Exchange for the period 1989 to 1996 FMA-kroniek 2000. Faculteit der Economische Wetenschappen, Erasmus Universiteit, Rotterdam, The Netherlands
Gardner, S. and le Roux, N.J. Discriminant Analysis Using Principal Curves in Biplots SASA: Annual South African Statistical Association Conference, 8–10 November 2000, Johannesburg
Le Roux, N.J. and Gardner, S. Biplot methodology everywhere: From quality control to stinkwood SASA: Annual South African Statistical Association Conference, 8–10 November 2000, Johannesburg
Gardner, S. and le Roux, N.J. Applying Bootstrapping Techniques to PCA and CVA Biplots SASA: Annual South African Statistical Association Conference, 3–5 November 1999, Durban
Van Blerk, S.P., le Roux, N.J. and Gardner, S. S-Plus Functions for Interactive Linear and Non-linear Biplots SASA: Annual South African Statistical Association Conference, 3–5 November 1999, Durban
Le Roux, N.J. and Gardner, S. An Application of the EM Algorithm to a Left-Censored Statistical Problem in Industry SASA: Annual South African Statistical Association Conference, 4–6 November 1998, Midrand
Gardner, S., Baard, E.H.W. and le Roux, N.J. How many are there? Fifth Herpetological Association of Africa Symposium, 16 September 1998, Stellenbosch.
Le Roux, N.J. and Gardner, S. Estimating the detection probability of geometric tortoises using designed experiments under field conditions SASA: Annual South African Statistical Association Conference, 5–7 November 1997, Dikhololo