1
$\begingroup$

I have a matrix of pairwise Gower dissimilarities (i.e. a non-Euclidean metric) among 48 objects derived from observations of 54 variables.

I want to use fuzzy clustering to obtain a matrix of group membership probabilities for these objects.

I successfully applied function fanny() from package {cluster} with k (number of groups) = 4.

However, for each sample, the resulting group membership probabilities for groups 1, 2 and 4 are identical. That is, they differ between samples, but within a sample they are identical, and differ from the membership probability for group 3.

I tested the function with k of 5, 6 and 7 and obtained the same result. For each k, the group membership probabilities were identical (within an object), except for group 3.

Does anyone know why this might be happening? I've read up on the fanny() algorithm a little but I'm out of my depth.

Reproducible code (NB: actual data follow due to size):

install.packages("cluster")
library("cluster")
WRS_fanny <- fanny(WRS_abiotic_gower, k = 4, memb.exp = 1.6)
boxplot(WRS_fanny$membership) # Note identical probabilities except group 3

Used dump() to generate this expression to recreate my data (warning: 294 lines):

WRS_abiotic_gower <-
structure(c(0.146778126529408, 0.233395130892759, 0.230707834408444, 
0.107759542541761, 0.138550796015413, 0.250065889538291, 0.296457361775224, 
0.304125211829354, 0.249782393842249, 0.282431780327495, 0.25970664977036, 
0.251596311648883, 0.224076607905674, 0.251036300151136, 0.196484552504834, 
0.271536343873702, 0.265568257890046, 0.301386804224653, 0.333063701373033, 
0.243600972251144, 0.270222184812288, 0.202047498980117, 0.25607063775203, 
0.28432667481917, 0.24092419965811, 0.275398059343259, 0.353270223771568, 
0.410364714292939, 0.313001378801364, 0.31925605598341, 0.357701120460457, 
0.374474795997226, 0.189102942457199, 0.202055462100059, 0.247583708657342, 
0.30145619413158, 0.296669857875146, 0.339864474596941, 0.229211008702165, 
0.352892440280298, 0.419167648505487, 0.375568557956858, 0.408480716527057, 
0.357157487108125, 0.32104738586095, 0.340665462218034, 0.41112214935789, 
0.23830604032674, 0.220478976300685, 0.144406224105715, 0.131515885009171, 
0.216908812847801, 0.243564070814677, 0.303148174678537, 0.259847622410418, 
0.247305687153991, 0.247843057599577, 0.26631554306528, 0.199890462938375, 
0.28044167137188, 0.236573345659676, 0.264633258654337, 0.250360278612784, 
0.282905316954283, 0.28148360026523, 0.172675632607707, 0.227157538886476, 
0.236004956068931, 0.275979625457648, 0.277843987366973, 0.262417869004574, 
0.281232496061673, 0.329892724118953, 0.394824895894531, 0.30265363625644, 
0.30621966032146, 0.34479178515701, 0.374683684901749, 0.21424820401553, 
0.195572916452556, 0.241393648501288, 0.316572600921197, 0.287133512655544, 
0.328215112402773, 0.193182214935908, 0.310935856747777, 0.373166961778132, 
0.332783318074841, 0.372234839389727, 0.330623742512386, 0.292078433204333, 
0.319545503079129, 0.361321516105163, 0.113028782648282, 0.206941169638988, 
0.20512668072602, 0.24722346523851, 0.308687244396935, 0.204828946418389, 
0.178919076974325, 0.183060785216104, 0.141776960257189, 0.134674581851856, 
0.25068097397968, 0.123958293735287, 0.141125483626521, 0.207978432341651, 
0.164949716625781, 0.190523417026307, 0.309000477229615, 0.277339046266308, 
0.313375054970243, 0.146793857852403, 0.137385394610465, 0.167578392653176, 
0.16804367314817, 0.171809114878496, 0.381176414723976, 0.457052466454844, 
0.282197699921021, 0.280739699172475, 0.302250296861788, 0.304432773653582, 
0.15957945901212, 0.235669994183549, 0.178160953420343, 0.282371461962546, 
0.257100104835312, 0.482706722426562, 0.369944192447982, 0.309346584211358, 
0.397210372391609, 0.380583112959886, 0.407248184382802, 0.346695417169584, 
0.307512606916341, 0.269834685656257, 0.409392428767859, 0.217511509030952, 
0.197481259895392, 0.275939181123016, 0.341312211621435, 0.228966719294035, 
0.188816895891077, 0.212202206485866, 0.194008885613182, 0.166989986763656, 
0.302101187053358, 0.162535754002973, 0.189263438443349, 0.23307417010102, 
0.199298488543463, 0.229916212413065, 0.31125875417897, 0.239297777451497, 
0.305776102461332, 0.173662348649529, 0.190044248152056, 0.206426618003735, 
0.227187931768048, 0.214824072433246, 0.4073186103118, 0.462804478914285, 
0.323506990767481, 0.317824328727341, 0.335245136426698, 0.327528602013808, 
0.185454797734023, 0.208467311764833, 0.135322000283485, 0.288836940944495, 
0.230306186711877, 0.468573333942388, 0.33313401147229, 0.321113074211735, 
0.391514664657562, 0.389710934558845, 0.400420981243808, 0.354101457148739, 
0.320629082713082, 0.286100626725499, 0.421671705461507, 0.091850113801114, 
0.246467223254679, 0.293547268483122, 0.297659239034206, 0.25115255052786, 
0.262514071750454, 0.238133038325391, 0.212967201979357, 0.17308253395046, 
0.2183920945381, 0.176101353198788, 0.261139515088514, 0.25711901874235, 
0.272641088130901, 0.330933912386848, 0.250239547033252, 0.236589210839988, 
0.172880533811394, 0.250922420164451, 0.268025493833902, 0.23575916232682, 
0.267647109568082, 0.373655060045483, 0.433323699677838, 0.31391657516819, 
0.31852460096763, 0.351258764865077, 0.367159819051078, 0.16890813868034, 
0.185782013611323, 0.226257665322096, 0.24834469424724, 0.272259607740838, 
0.354585293042834, 0.229701146851508, 0.362102176288281, 0.400717876478831, 
0.36797070590943, 0.409120131929636, 0.34498319198954, 0.313386283542958, 
0.331016784762028, 0.384254565970275, 0.22441721238447, 0.290598912970728, 
0.298643689422108, 0.250361457068466, 0.244928708085188, 0.237713058207576, 
0.222774529861816, 0.210265153710359, 0.235732385132754, 0.20156761561874, 
0.262015784293767, 0.259883660151181, 0.288278458785541, 0.333285662718476, 
0.232716863284767, 0.254484337442487, 0.187205171211865, 0.243100325138505, 
0.267048020813995, 0.242204808310273, 0.261920262726918, 0.380811106291807, 
0.446215322818477, 0.316835287136048, 0.321422073497405, 0.348976941617111, 
0.382762337202703, 0.182491613841568, 0.215977568407392, 0.226450258451914, 
0.283179718136393, 0.274849250694097, 0.369155318338422, 0.220594923901695, 
0.355713153122709, 0.412492946083189, 0.382970482523399, 0.431482115624372, 
0.34255354874582, 0.347795938665851, 0.34955910382006, 0.420245136110264, 
0.157812677685306, 0.272010868942531, 0.229427228507228, 0.145577425709495, 
0.263408013897356, 0.321273834678714, 0.253868813151803, 0.303315771029787, 
0.250638531578023, 0.202686048164595, 0.23542311767865, 0.262524337712699, 
0.213762545265516, 0.198592502804593, 0.289755608760079, 0.291055349247771, 
0.21471221044029, 0.233375528166048, 0.214477494584816, 0.227000414408994, 
0.253378560228127, 0.327233596552946, 0.256069951388544, 0.241731882033173, 
0.239086155905498, 0.301355179254736, 0.268623586092357, 0.216004437464011, 
0.278442814851357, 0.351355765511319, 0.306053836025685, 0.385664345928335, 
0.325740726127523, 0.224406635623224, 0.272261471513539, 0.269731865914167, 
0.301560017458275, 0.225721846096926, 0.229981204614567, 0.242518355133113, 
0.328463376740603, 0.329111361926846, 0.264116154396599, 0.217010031466845, 
0.313943303264908, 0.363879592011647, 0.257108399675198, 0.358515803949734, 
0.321567175057474, 0.296784046059782, 0.301131134388745, 0.331842299269796, 
0.253436530987525, 0.259557088485383, 0.301283759065815, 0.343075324682922, 
0.283687903142085, 0.283592914904744, 0.264059283720674, 0.287527855889611, 
0.188324610310514, 0.230742624643993, 0.228533751670285, 0.193858413416879, 
0.196462593078236, 0.26351603992366, 0.320788863971364, 0.24636937131769, 
0.318763516486424, 0.426609873329301, 0.366219134961131, 0.378499967117754, 
0.337661758976989, 0.271583947417078, 0.314249960298854, 0.270201122918241, 
0.246946815781063, 0.215102704787387, 0.236134173342779, 0.286232978295626, 
0.350696874593699, 0.164627981394906, 0.205527499202434, 0.270434850920206, 
0.243134003521468, 0.351050952165932, 0.219183969305488, 0.242246176734031, 
0.172067162427782, 0.128130370968335, 0.134122968993382, 0.257281689657044, 
0.299403006982152, 0.422642508788569, 0.228408163742806, 0.11957268044525, 
0.159438669856483, 0.14868234714726, 0.136918222749012, 0.286755138375814, 
0.354634021682536, 0.181731358904613, 0.193212405876045, 0.224667151942299, 
0.203734363544203, 0.243482257894911, 0.289366500456441, 0.252436960541827, 
0.405666704589028, 0.373065503109924, 0.524026234338112, 0.435325641487625, 
0.2554099549592, 0.333929718431462, 0.296689595118324, 0.317661622659771, 
0.259343552195757, 0.220649936386088, 0.163406146367423, 0.385366843416753, 
0.17361870009857, 0.202311917654341, 0.227649249888414, 0.272307292144977, 
0.209258820602416, 0.19319876548376, 0.176481382795848, 0.155899766048858, 
0.20344820709624, 0.264821880206708, 0.261204867940355, 0.327272602852553, 
0.189095535111204, 0.133280535811196, 0.113962382478816, 0.133224369074271, 
0.140065242738296, 0.324893451169475, 0.363116475102291, 0.237103967908121, 
0.242041052773962, 0.270256227204134, 0.287338997227553, 0.173155053909376, 
0.189424483944132, 0.187175303832514, 0.348464842038111, 0.288446217937334, 
0.470765306868106, 0.343131708273399, 0.252938015143712, 0.336888277495862, 
0.301191263319341, 0.356500481509341, 0.301312706960525, 0.267001426016706, 
0.237755741422434, 0.373181832858731, 0.210970882604491, 0.251097175595452, 
0.263098712824128, 0.239269004043719, 0.227818986615428, 0.204715476224745, 
0.207743502877001, 0.217031686744224, 0.250740570083614, 0.228549792422889, 
0.32207055314749, 0.214569147096824, 0.168053926099824, 0.181896968150084, 
0.17623993474032, 0.188910784920792, 0.329236353931487, 0.406757003827438, 
0.21912863831964, 0.222918637259912, 0.233057683009712, 0.279883139925161, 
0.254158158514965, 0.20158263820538, 0.240723178073065, 0.357575151419053, 
0.315084566107509, 0.420672711597265, 0.367274077713619, 0.249934355335581, 
0.318059702631574, 0.31801009061305, 0.307702024506444, 0.272796141745462, 
0.248783767482011, 0.224074353894395, 0.36569822014514, 0.187028191009587, 
0.241049094175669, 0.179339223070881, 0.156157306332836, 0.227513629426693, 
0.202623928640432, 0.246026699193367, 0.33156658615291, 0.315376540691078, 
0.289484137778374, 0.184409694862884, 0.21876550228219, 0.191376542617272, 
0.225070995275441, 0.210475769133431, 0.406320939903412, 0.470184911435262, 
0.283288686913745, 0.310862038618383, 0.326344244418466, 0.354367208429555, 
0.145546897876123, 0.236312084449821, 0.228164131483865, 0.299496818623249, 
0.262731741465948, 0.481980331569159, 0.365549756268789, 0.304206259846763, 
0.404226312619428, 0.378666518283215, 0.427829473290829, 0.410076196767098, 
0.354844586875853, 0.322995610040716, 0.442244062657121, 0.264970270646247, 
0.108746238733874, 0.193352911535009, 0.266719534733286, 0.227013610318163, 
0.238449830517912, 0.347321221639697, 0.323042902522987, 0.309345473650974, 
0.152174920727296, 0.213300152179139, 0.214985014168209, 0.235666919359841, 
0.252242068781554, 0.42709913553219, 0.485189051211046, 0.293088179216135, 
0.329679671628233, 0.33035798397786, 0.346527393314769, 0.179522572086687, 
0.278345689579152, 0.232251261676667, 0.287551912653317, 0.278265167614771, 
0.484670259785051, 0.377718756380607, 0.359121022926639, 0.445377414543919, 
0.401184662139802, 0.451462061652599, 0.400960453366808, 0.357848562271756, 
0.32669976446978, 0.453658939812252, 0.240146917990639, 0.230300655485122, 
0.311042661085334, 0.317612855832712, 0.337564267124495, 0.349956630228225, 
0.262974415301128, 0.242242668807266, 0.253380207155479, 0.289677826481165, 
0.293660554070656, 0.293778024707369, 0.316830788871491, 0.350345490654708, 
0.395195391031732, 0.33513375069398, 0.337179146242041, 0.371234921705163, 
0.39695509160543, 0.242891611224244, 0.250345225015281, 0.335701615323364, 
0.312734019064895, 0.325318419658978, 0.337878664200963, 0.253340263691725, 
0.374161000604498, 0.42535575946078, 0.357273207425347, 0.390814126325831, 
0.37145277419384, 0.331269154759241, 0.35876947913107, 0.352172345260752, 
0.142765226117177, 0.235679681653265, 0.184818072498785, 0.191253138910713, 
0.348695224683716, 0.310876918777759, 0.356345526377818, 0.119856934587125, 
0.18558608732922, 0.218834189019569, 0.222467207064484, 0.214665638336601, 
0.409416658003954, 0.486474197840857, 0.297515550101008, 0.295394752220839, 
0.322174630895094, 0.325738052143967, 0.132596245884175, 0.246268939070485, 
0.237445084809875, 0.296085703183638, 0.30967198389911, 0.514235890211653, 
0.410886481296546, 0.356238394380928, 0.444278663072277, 0.413799296345893, 
0.423845525648207, 0.385961408460294, 0.331592257597649, 0.288799203168772, 
0.442915990670296, 0.197022259697264, 0.175507567684546, 0.194255251918258, 
0.33082685023071, 0.309916538911981, 0.31654082290413, 0.108210668457586, 
0.190395423695379, 0.19168132680145, 0.208726249609115, 0.189951871401416, 
0.380558729308507, 0.450713427014334, 0.29221794299639, 0.289788592951392, 
0.318621931141074, 0.342289641611819, 0.111392920848469, 0.238016295941358, 
0.233024569363059, 0.283486747172187, 0.296984641557404, 0.501886736277605, 
0.354691839582922, 0.340610686032757, 0.422424356332051, 0.384338929876594, 
0.40094086257798, 0.379526405421168, 0.312309452815408, 0.288243747328821, 
0.442756689368451, 0.0978020742858896, 0.14238454435033, 0.224074878211512, 
0.272789288372412, 0.336958268324688, 0.230384388811536, 0.153772250555725, 
0.131424564857863, 0.135138107161081, 0.133890774320702, 0.272263168743922, 
0.334611561341041, 0.201012647896807, 0.201584220387737, 0.208839157389968, 
0.256579613931989, 0.195090930348769, 0.239667311414397, 0.229812436589804, 
0.325585931893025, 0.283778980685324, 0.478526612005615, 0.356639373275897, 
0.241909246023086, 0.305460399238216, 0.27867526153966, 0.322412981417394, 
0.277171351783218, 0.229900157930983, 0.195715920825032, 0.39572261842839, 
0.0885419178364805, 0.260829077668881, 0.285604227212454, 0.358309944800871, 
0.191297070527283, 0.126235720835498, 0.109249713673671, 0.14254483589829, 
0.114098495759652, 0.30083929190514, 0.37020704542986, 0.1958702964902, 
0.197870970618193, 0.236326226170556, 0.252004892063645, 0.172915994311976, 
0.243168478593422, 0.215401946288142, 0.34974266738716, 0.299793278166279, 
0.495198823266587, 0.367763979943646, 0.242791995631133, 0.337673441490117, 
0.307139045113223, 0.337144126944256, 0.307001967739705, 0.247488011208742, 
0.193434061388901, 0.428281034806268, 0.284047884441708, 0.297179320626955, 
0.398472912489279, 0.189422027088779, 0.139174701703958, 0.13546793385265, 
0.161371430634921, 0.168372359428332, 0.311782400400275, 0.399530125695683, 
0.204724384598228, 0.201801211542734, 0.228630624490025, 0.244227565066874, 
0.231236249512786, 0.282283778304694, 0.270960643953082, 0.339857569718471, 
0.326823797526486, 0.50790279274637, 0.416875008383526, 0.282152460994984, 
0.357858660816522, 0.333641345463762, 0.329844433417204, 0.303489492239208, 
0.248763158823102, 0.18972472338955, 0.421183075535043, 0.238876684527487, 
0.345436792453969, 0.336061495089022, 0.263723105832666, 0.269158312858497, 
0.257569542737216, 0.254101022613423, 0.232340609914943, 0.288048749871818, 
0.23893258972811, 0.235307782197714, 0.245368590919873, 0.218291406006654, 
0.316141295974322, 0.24955937510941, 0.275398481408491, 0.397779405844502, 
0.33235739043674, 0.474488798783166, 0.379555493234099, 0.117498927565631, 
0.150698463433954, 0.139639944784483, 0.201302528451723, 0.147727036921414, 
0.110443516933975, 0.207973626843108, 0.2349144537945, 0.261908907223673, 
0.282645509769686, 0.276899906898298, 0.298349708345499, 0.269341140045141, 
0.280406506125865, 0.288913750994849, 0.347891634321888, 0.303388807579801, 
0.281966082920489, 0.30160734823309, 0.312672145150089, 0.289560106847955, 
0.232441075572291, 0.251245870030593, 0.307878521523741, 0.253177898598542, 
0.367223667445015, 0.261958529238038, 0.281362238133638, 0.28801781739124, 
0.270009069548595, 0.299522785484746, 0.257219705028688, 0.221415622921201, 
0.255820765239848, 0.28828981955977, 0.31671582928228, 0.363745505468365, 
0.347939689625386, 0.345267789614021, 0.350823668439948, 0.364495975648929, 
0.366870882161216, 0.385114088795543, 0.394103211364437, 0.395775639313918, 
0.431759745459385, 0.285752359669562, 0.218397737527923, 0.267855815397473, 
0.276016579434273, 0.212495440354826, 0.291102629917947, 0.213970649897841, 
0.366795421768988, 0.346449786640165, 0.342290797217175, 0.415599276580519, 
0.380336211685697, 0.349467695816019, 0.364180183329975, 0.337126810775529, 
0.181804519234005, 0.18062902539593, 0.205007684433831, 0.215420308066645, 
0.374535630704164, 0.448671109202557, 0.274007859625578, 0.289718981226722, 
0.317449365559063, 0.344436310953225, 0.0867015061200141, 0.214204649166454, 
0.215447575226592, 0.264794874484955, 0.282581926460504, 0.484608914272993, 
0.348667454528334, 0.32893804711248, 0.414555319322939, 0.385124997651254, 
0.388063868142764, 0.354930509942296, 0.314210175323553, 0.299205156883234, 
0.421392543584554, 0.100685059696492, 0.0866995692711282, 0.0969095988503732, 
0.303792476166297, 0.382897246418713, 0.200846642991439, 0.207028847006805, 
0.235355971825502, 0.242986796699078, 0.207057482359656, 0.2687412718472, 
0.221962952421413, 0.344331259710073, 0.330688322004791, 0.474942339215751, 
0.385638847415413, 0.251038412436203, 0.331532314029424, 0.3114598183918, 
0.347948011007012, 0.270448613080749, 0.244297789908784, 0.204995495462879, 
0.350844315404954, 0.100911244045508, 0.103185755602834, 0.303917784269364, 
0.362849882087611, 0.202367178640256, 0.223049633935698, 0.249463049219082, 
0.283916535235254, 0.181320446598951, 0.245084575129691, 0.214677803390247, 
0.366103538705351, 0.305876565476593, 0.494825605888924, 0.361478033843841, 
0.248975697592638, 0.337313396652572, 0.301301052404624, 0.341462191338638, 
0.312817106125548, 0.27311011394114, 0.239013977072195, 0.396845918590528, 
0.107924690281289, 0.270050462910416, 0.348802966709437, 0.184161895866205, 
0.19278817419054, 0.208020692062944, 0.242414996189593, 0.220172380542586, 
0.233584142548741, 0.217618000702973, 0.345697450080864, 0.313839355336015, 
0.434547000124388, 0.359186021565848, 0.267208517073225, 0.32330173927609, 
0.30518274090545, 0.34529655389533, 0.262508097267023, 0.227176931450904, 
0.204689406161101, 0.361105343888977, 0.30571330885646, 0.367599747989144, 
0.217475081775334, 0.225772086317862, 0.254256629249112, 0.247586478503354, 
0.202555021235713, 0.238681639695241, 0.197751473539488, 0.37176189816412, 
0.317335702325625, 0.49533353822436, 0.363789246350344, 0.254818852710107, 
0.310725186653894, 0.293853581633784, 0.345640005875408, 0.289048614316403, 
0.248412043950396, 0.214293019014908, 0.387475214055207, 0.127715354802369, 
0.223361776933178, 0.20504999812424, 0.19419269144831, 0.222443662573356, 
0.363848133977628, 0.310299864585179, 0.356418806901375, 0.426643530706364, 
0.384599879799222, 0.456927976196206, 0.3856587938183, 0.235397342626925, 
0.276899592755987, 0.231249267705255, 0.22606279999052, 0.183932484187818, 
0.183332809218275, 0.233138159218437, 0.319631133798301, 0.276221233500258, 
0.249619172891433, 0.234864688890259, 0.2534011126405, 0.422547172125712, 
0.354971954715825, 0.399303016835905, 0.425140805653638, 0.396632912535974, 
0.473365299786863, 0.387309733261674, 0.290139703736607, 0.255261478630608, 
0.192826774657939, 0.196399242991551, 0.221163737535614, 0.245646551500451, 
0.270630500732627, 0.350486952979949, 0.0812114642376115, 0.108500113815981, 
0.152246295653802, 0.277240627186762, 0.276720261356458, 0.31032055938721, 
0.388673098686631, 0.349432716682413, 0.475610259715878, 0.438195382601128, 
0.235959199160122, 0.316260782927578, 0.245911688896529, 0.23743988210527, 
0.218712106892772, 0.178816541166305, 0.178230220796603, 0.379833762104026, 
0.0784463617489709, 0.129997140263035, 0.291085148419097, 0.273257526667692, 
0.306557221428694, 0.402153280417114, 0.364282996217115, 0.463352273325088, 
0.431063703093528, 0.222304690496031, 0.291674227758824, 0.241221392372485, 
0.210744722052842, 0.194787521424541, 0.167160218115454, 0.150755475480528, 
0.37885166947424, 0.135279579197833, 0.327926450188976, 0.298559515112429, 
0.318417810243592, 0.409380013643058, 0.364524911114103, 0.488857362760066, 
0.466801626528242, 0.231271124782347, 0.290704260349066, 0.257441555634786, 
0.219539177105795, 0.185785463529339, 0.190539666493475, 0.164885095495906, 
0.400661447880847, 0.351670664342995, 0.293106495448539, 0.278927612321467, 
0.41056998548736, 0.352891397933641, 0.518833547693511, 0.491661977916097, 
0.229382920274352, 0.292629764083707, 0.226989823245877, 0.216704505053967, 
0.182937025703239, 0.158253530543942, 0.158729282293997, 0.356682252224064, 
0.189510186934412, 0.200144695957883, 0.267522818117134, 0.247590590638521, 
0.490647848397164, 0.325163873345429, 0.291292316062298, 0.390440113550956, 
0.357936796896738, 0.405263499885725, 0.370252764588065, 0.322692323050225, 
0.306120087223696, 0.421325571167844, 0.167539006000027, 0.269020719809449, 
0.223042339002822, 0.38760404469828, 0.275161689978891, 0.242363068276669, 
0.299763159742022, 0.295721854984686, 0.316816505510713, 0.280958787086803, 
0.242920147198185, 0.27387569756998, 0.346646422960218, 0.296032978704237, 
0.171471904196341, 0.455226711060175, 0.306302086043222, 0.270092447713217, 
0.330576945364237, 0.328073318126048, 0.379232696180287, 0.305191216068878, 
0.287928376535759, 0.281784904626341, 0.400754470522899, 0.183297028965347, 
0.439603470995397, 0.324142275296304, 0.416842097225044, 0.334144320356283, 
0.331280399040641, 0.361642381662566, 0.395220939617569, 0.348409804637902, 
0.33437908671065, 0.413423564393322, 0.413752235847781, 0.309263065288595, 
0.335337798740467, 0.313696283268453, 0.324026564106507, 0.370850321127701, 
0.367711294816184, 0.318257687382319, 0.282250272793762, 0.405957887669014, 
0.289062022286134, 0.500989225264607, 0.469590271510581, 0.465402652530193, 
0.4884729148024, 0.474410320519324, 0.453387206453657, 0.472498468887031, 
0.428171148682882, 0.415945155744945, 0.361501568460874, 0.351686833699556, 
0.425332115878206, 0.420330132379335, 0.3849261129704, 0.416859526057763, 
0.408207585207454, 0.144955775692482, 0.162810593772454, 0.222289443174366, 
0.174772219403487, 0.153368630325598, 0.212286474750986, 0.27740056732249, 
0.107301136884498, 0.159183884060135, 0.189989069644874, 0.172538300775432, 
0.202263114833207, 0.260439883936975, 0.118388242752457, 0.165081626468155, 
0.140322059005816, 0.185185767078914, 0.260065955820617, 0.137793449327493, 
0.147346740832392, 0.191053507374825, 0.322728564748582, 0.105659036172812, 
0.205131400541044, 0.265657065294917, 0.138708922010367, 0.250058789949686, 
0.310423445004488), class = c("dissimilarity", "dist"), Labels = c("1", 
"2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", 
"14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", 
"25", "26", "27", "28", "29", "30", "31", "32", "33", "34", "35", 
"36", "37", "38", "39", "40", "41", "42", "43", "44", "45", "46", 
"47", "48"), Size = 48L, Metric = "mixed", Types = c("I", "I", 
"I", "I", "I", "I", "I", "I", "I", "I", "I", "I", "I", "I", "I", 
"I", "I", "I", "N", "I", "I", "I", "I", "I", "I", "I", "I", "I", 
"I", "I", "I", "I", "I", "I", "I", "I", "I", "I", "I", "I", "I", 
"I", "I", "I", "I", "I", "I", "I", "I", "I", "I", "I", "I", "I"
))
$\endgroup$

migrated from stackoverflow.com Jun 10 '16 at 13:51

This question came from our site for professional and enthusiast programmers.

  • $\begingroup$ try to change the value of memb.exp, it should help $\endgroup$ – Cath Jun 10 '16 at 7:17
  • $\begingroup$ Alas, it does not. $\endgroup$ – mixtrak Jun 10 '16 at 11:58
  • $\begingroup$ I tried with memb.exp=1.1 and membership probabilities are much more "drastic"... (around 98%-99% for the first objects) $\endgroup$ – Cath Jun 10 '16 at 13:23
  • $\begingroup$ Thanks - I jumped to conclusions and didn't explore a wide enough range of memb.exp values. Turns out, below about 1.5, the group memberships begin to diverge. Any idea why? If this was posted as a solution, it would be accepted ;) $\endgroup$ – user119630 Jun 11 '16 at 9:02
  • $\begingroup$ If I had to guess, I'd imagine this is complete fuzziness for all group memberships except one, which would explain why increasing crispness resolves the tie. I suppose that implies the clustering is only robust for one group, and the others should be interpreted with caution? $\endgroup$ – user119630 Jun 11 '16 at 9:09
0
$\begingroup$

The parameter memb.exp determines the degree of fuzziness. depending on your data, the best value can be 1.8 or 1.05, hence there is no perfect value. The higher the value is, the more fuzziness you introduce in the clustering.

You can have a look at Bora et al., which discusses more thoroughly about the topic.

I hope this helps you at least a bit.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy