pyUPMASK: an improved unsupervised clustering algorithm

Aims. We present pyUPMASK, an unsupervised clustering method for stellar clusters that builds upon the original UPMASK package. The general approach of this method makes it plausible to be applied to analyses that deal with binary classes of any kind as long as the fundamental hypotheses are met. Th...

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Published inAstronomy and astrophysics (Berlin) Vol. 650; p. A109
Main Authors Pera, M. S., Perren, G. I., Moitinho, A., Navone, H. D., Vazquez, R. A.
Format Journal Article
LanguageEnglish
Published Heidelberg EDP Sciences 01.06.2021
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Online AccessGet full text
ISSN0004-6361
1432-0746
1432-0746
DOI10.1051/0004-6361/202040252

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Abstract Aims. We present pyUPMASK, an unsupervised clustering method for stellar clusters that builds upon the original UPMASK package. The general approach of this method makes it plausible to be applied to analyses that deal with binary classes of any kind as long as the fundamental hypotheses are met. The code is written entirely in Python and is made available through a public repository. Methods. The core of the algorithm follows the method developed in UPMASK but introduces several key enhancements. These enhancements not only make pyUPMASK more general, they also improve its performance considerably. Results. We thoroughly tested the performance of pyUPMASK on 600 synthetic clusters affected by varying degrees of contamination by field stars. To assess the performance, we employed six different statistical metrics that measure the accuracy of probabilistic classification. Conclusions. Our results show that pyUPMASK is better performant than UPMASK for every statistical performance metric, while still managing to be many times faster.
AbstractList Aims. We present pyUPMASK, an unsupervised clustering method for stellar clusters that builds upon the original UPMASK package. The general approach of this method makes it plausible to be applied to analyses that deal with binary classes of any kind as long as the fundamental hypotheses are met. The code is written entirely in Python and is made available through a public repository. Methods. The core of the algorithm follows the method developed in UPMASK but introduces several key enhancements. These enhancements not only make pyUPMASK more general, they also improve its performance considerably. Results. We thoroughly tested the performance of pyUPMASK on 600 synthetic clusters affected by varying degrees of contamination by field stars. To assess the performance, we employed six different statistical metrics that measure the accuracy of probabilistic classification. Conclusions. Our results show that pyUPMASK is better performant than UPMASK for every statistical performance metric, while still managing to be many times faster.
Aims. We present pyUPMASK, an unsupervised clustering method for stellar clusters that builds upon the original UPMASK package. The general approach of this method makes it plausible to be applied to analyses that deal with binary classes of any kind as long as the fundamental hypotheses are met. The code is written entirely in Python and is made available through a public repository. Methods. The core of the algorithm follows the method developed in UPMASK but introduces several key enhancements. These enhancements not only make pyUPMASK more general, they also improve its performance considerably. Results. We thoroughly tested the performance of pyUPMASK on 600 synthetic clusters affected by varying degrees of contamination by field stars. To assess the performance, we employed six different statistical metrics that measure the accuracy of probabilistic classification. Conclusions. Our results show that pyUPMASK is better performant than UPMASK for every statistical performance metric, while still managing to be many times faster.
Author Navone, H. D.
Moitinho, A.
Perren, G. I.
Vazquez, R. A.
Pera, M. S.
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Cites_doi 10.1051/0004-6361:20040297
10.1111/j.1466-8238.2007.00358.x
10.1051/0004-6361/201731251
10.1051/0004-6361/201833476
10.1109/MCSE.2011.37
10.1051/0004-6361/201834957
10.2307/3212829
10.1051/0004-6361/201424946
10.1109/MCSE.2007.55
10.1016/j.patrec.2013.12.011
10.1287/deca.2013.0280
10.1371/journal.pone.0080914
10.1201/b19708
10.3847/1538-3881/aac387
10.1007/978-1-4419-9863-7_1371
10.1155/2013/753475
10.1175/1520-0493(1950)078<0001:VOFEIT>2.0.CO;2
10.1111/j.2517-6161.1979.tb01091.x
10.1111/j.2517-6161.1977.tb01600.x
10.1051/0004-6361/202039657
10.1051/0004-6361/201321143
10.1051/0004-6361/201833051
10.1086/107787
10.1086/114773
10.1051/0004-6361/201322068
10.1145/235815.235821
10.1515/crll.1908.133.97
10.1051/0004-6361/201935599
10.1093/mnras/stz3610
10.1111/j.2517-6161.1952.tb00104.x
10.1051/0004-6361/201629272
10.1007/978-0-387-30164-8_547
10.1126/science.1242072
10.1016/0005-2795(75)90109-9
10.1007/s10994-009-5119-5
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References Ripley (R38) 1979; 41
Carrera (R12) 2019; 627
Hand (R19) 2009; 77
Vasilevskis (R46) 1958; 63
Good (R18) 1952; 14
Krone-Martins (R26) 2014; 561
Tollerud (R43) 2019; 51
R25
R27
Ripley (R37) 1976; 13
R29
Lobo (R28) 2008; 17
Merkle (R32) 2013; 10
R3
Rodriguez (R39) 2014; 344
R6
Cantat-Gaudin (R11) 2019; 626
Dempster (R13) 1977; 39
Hernández-Orallo (R21) 2012; 13
Balaguer-Núñez (R4) 2020; 492
Hunter (R22) 2007; 9
Brown (R17) 2021; 649
Perren (R36) 2015; 576
R34
R33
Cantat-Gaudin (R10) 2018; 615
Hand (R20) 2014; 40
Barber (R5) 1996; 22
Cabrera-Cano (R8) 1990; 235
Cantat-Gaudin (R9) 2018; 618
Voronoi (R47) 1908; 1908
R41
Matthews (R31) 1975; 405
R42
Robitaille (R1) 2013; 558
R45
R49
R48
Brown (R16) 2018; 616
Van Der Walt (R44) 2011; 13
Marcon (R30) 2013; 2013
R14
Price-Whelan (R2) 2018; 156
Jones (R24) 1988; 95
Brier (R7) 1950; 78
Javakhishvili (R23) 2006; 447
Sanders (R40) 1971; 14
Prusti (R15) 2016; 595
Pedregosa (R35) 2011; 12
References_xml – volume: 447
  start-page: 915
  year: 2006
  ident: R23
  publication-title: A&A
  doi: 10.1051/0004-6361:20040297
– volume: 17
  start-page: 145
  year: 2008
  ident: R28
  publication-title: Global Ecol. Biogeogr.
  doi: 10.1111/j.1466-8238.2007.00358.x
– volume: 615
  start-page: A49
  year: 2018
  ident: R10
  publication-title: A&A
  doi: 10.1051/0004-6361/201731251
– volume: 618
  start-page: A93
  year: 2018
  ident: R9
  publication-title: A&A
  doi: 10.1051/0004-6361/201833476
– volume: 13
  start-page: 22
  year: 2011
  ident: R44
  publication-title: Comput. Sci. Eng.
  doi: 10.1109/MCSE.2011.37
– ident: R42
– volume: 51
  start-page: 180
  year: 2019
  ident: R43
  publication-title: Bull. Am. Astron. Soc.
– volume: 626
  start-page: A17
  year: 2019
  ident: R11
  publication-title: A&A
  doi: 10.1051/0004-6361/201834957
– ident: R33
– volume: 13
  start-page: 255
  year: 1976
  ident: R37
  publication-title: J. Appl. Probab.
  doi: 10.2307/3212829
– volume: 576
  start-page: A6
  year: 2015
  ident: R36
  publication-title: A&A
  doi: 10.1051/0004-6361/201424946
– volume: 9
  start-page: 90
  year: 2007
  ident: R22
  publication-title: Comput. Sci. Eng.
  doi: 10.1109/MCSE.2007.55
– volume: 40
  start-page: 41
  year: 2014
  ident: R20
  publication-title: Pattern Recognit. Lett.
  doi: 10.1016/j.patrec.2013.12.011
– ident: R29
– volume: 10
  start-page: 292
  year: 2013
  ident: R32
  publication-title: Decis. Anal.
  doi: 10.1287/deca.2013.0280
– ident: R27
  doi: 10.1371/journal.pone.0080914
– volume: 235
  start-page: 94
  year: 1990
  ident: R8
  publication-title: A&A
– ident: R3
  doi: 10.1201/b19708
– volume: 12
  start-page: 2825
  year: 2011
  ident: R35
  publication-title: J. Mach. Learn. Res.
– volume: 156
  start-page: 123
  year: 2018
  ident: R2
  publication-title: AJ
  doi: 10.3847/1538-3881/aac387
– ident: R49
  doi: 10.1007/978-1-4419-9863-7_1371
– volume: 2013
  start-page: 1
  year: 2013
  ident: R30
  publication-title: ISRN Ecol.
  doi: 10.1155/2013/753475
– volume: 78
  start-page: 1
  year: 1950
  ident: R7
  publication-title: Mon. Weather Rev.
  doi: 10.1175/1520-0493(1950)078<0001:VOFEIT>2.0.CO;2
– volume: 41
  start-page: 368
  year: 1979
  ident: R38
  publication-title: J. R. Stat. Soc. Ser. B (Methodol.)
  doi: 10.1111/j.2517-6161.1979.tb01091.x
– volume: 39
  start-page: 1
  year: 1977
  ident: R13
  publication-title: J. R. Stat. Soc.: Ser. B (Methodol.)
  doi: 10.1111/j.2517-6161.1977.tb01600.x
– volume: 649
  start-page: A1
  year: 2021
  ident: R17
  publication-title: A&A
  doi: 10.1051/0004-6361/202039657
– volume: 14
  start-page: 226
  year: 1971
  ident: R40
  publication-title: A&A
– ident: R25
– volume: 561
  start-page: A57
  year: 2014
  ident: R26
  publication-title: A&A
  doi: 10.1051/0004-6361/201321143
– volume: 616
  start-page: A1
  year: 2018
  ident: R16
  publication-title: A&A
  doi: 10.1051/0004-6361/201833051
– volume: 63
  start-page: 387
  year: 1958
  ident: R46
  publication-title: AJ
  doi: 10.1086/107787
– volume: 95
  start-page: 1755
  year: 1988
  ident: R24
  publication-title: AJ
  doi: 10.1086/114773
– volume: 558
  start-page: A33
  year: 2013
  ident: R1
  publication-title: A&A
  doi: 10.1051/0004-6361/201322068
– volume: 22
  start-page: 469
  year: 1996
  ident: R5
  publication-title: ACM Trans. Math. Software
  doi: 10.1145/235815.235821
– volume: 1908
  start-page: 97
  year: 1908
  ident: R47
  publication-title: Journal für die reine und angewandte Mathematik
  doi: 10.1515/crll.1908.133.97
– ident: R14
– volume: 627
  start-page: A119
  year: 2019
  ident: R12
  publication-title: A&A
  doi: 10.1051/0004-6361/201935599
– volume: 492
  start-page: 5811
  year: 2020
  ident: R4
  publication-title: MNRAS
  doi: 10.1093/mnras/stz3610
– volume: 14
  start-page: 107
  year: 1952
  ident: R18
  publication-title: J. R. Stat. Soc.: Ser. B (Methodol.)
  doi: 10.1111/j.2517-6161.1952.tb00104.x
– ident: R45
– volume: 595
  start-page: A1
  year: 2016
  ident: R15
  publication-title: A&A
  doi: 10.1051/0004-6361/201629272
– ident: R41
– ident: R6
  doi: 10.1007/978-0-387-30164-8_547
– volume: 344
  start-page: 1492
  year: 2014
  ident: R39
  publication-title: Science
  doi: 10.1126/science.1242072
– volume: 405
  start-page: 442
  year: 1975
  ident: R31
  publication-title: Biochimica et Biophysica Acta (BBA) - Protein Structure
  doi: 10.1016/0005-2795(75)90109-9
– ident: R48
– volume: 13
  start-page: 2813
  year: 2012
  ident: R21
  publication-title: J. Mach. Learn. Res.
– volume: 77
  start-page: 103
  year: 2009
  ident: R19
  publication-title: Mach. Learn.
  doi: 10.1007/s10994-009-5119-5
– ident: R34
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Snippet Aims. We present pyUPMASK, an unsupervised clustering method for stellar clusters that builds upon the original UPMASK package. The general approach of this...
Aims. We present pyUPMASK, an unsupervised clustering method for stellar clusters that builds upon the original UPMASK package. The general approach of this...
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StartPage A109
SubjectTerms Algorithms
Binary stars
Clustering
Star clusters
Statistical analysis
Title pyUPMASK: an improved unsupervised clustering algorithm
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