QQ:2743438924
手机:0512-66159259
电话:0512-66159259
邮箱:tokai@tokais.net
地址:苏州相城黄埭高新区东桥聚民路68号
Documentation>
Functions>
Generalappliedmath,
Statistics
Performsk-meansclusteringviatheHartiganandWongAS-136algorithm.
Availableinversion6.3.0andlater.
functionkmeans_as136(
x:numericAS136钢材多少钱一千克,;floatordouble
k[1]:integer,
opt[1]:logical
return_val:floatordouble
Thereturnarray(say),clcnter,willcontainthecluster
centers.Itwillbedimensioned(k,N),whereN
collectivelyrepresentsthe'variable'dimension(s).
clcnterwillhavethefollowingattributesassociatedwithit:
id-aone-dimensionalintegerarrayof
sizeMindicatingtheclustertowhicheachobservationis
assigned.
npts-aone-dimensionalintegerarrayof
sizekcontainingthenumberofpointsineachcluster.
ss2-aone-dimensionaldoublearrayof
sizekcontainingthewithin-clustersumofsquares.
K-meansisacentroid-basedclustermethod.
Theobservationsareallocatedtokclustersinsuchawaythatthe
within-clustersumofsquaresisminimized.K-meansclusteringrequiresthat
thenumberofclusterstobeextractedbespecifiedinadvance.
Asnotedby
"Thenumberofclustersshouldmatchthedata.Anincorrectchoiceofthenumberofclusterswillinvalidatethewholeprocess.AnempiricalwaytofindthebestnumberofclustersistotryK-meansclusteringwithdifferentnumberofclustersandmeasuretheresultingsumofsquares."
Thek-meansalgorithmworksreasonablywellwhenthedatafitstheclustermodel:
Thenumberofclustersis'consistent'withthedata.
Thedatapointswithinaclusterarecenteredaroundthatcluster
Thespread/varianceoftheclustersissimilar,ieeachdatapointbelongstotheclosestcluster
Limitations:K-meansmayhaveproblemswhenclustersareofverydifferingsizes;
outliersarepresent;oremptyclustersexist.
TheoriginalcodeiscreatedforCartesiangrids.Iftheapplicationrequiresusinggridpoints
orstationslocatedathighlatitudes,itissuggestedthat
css2cbeused
tointerpolatetoCartesiancoordinates.Thesebetterreflectthetruedistancesandshouldbeinputtothefunction.
Themodifiedcodeusedbythisfunctionwasdownloadedfrom
JohnBurkardt'swebsite.
TheoriginalHartigan&WongFortrancodewasfrom:
JohnHartigan,ManchekWong,
AlgorithmAS136:
AK-MeansClusteringAlgorithm,
AppliedStatistics,
Volume28,Number1,1979,pages100-108.
Example1:Thesourceofthisexampleis
Defaultoptionsareused.
v0(/1.0AS136钢材多少钱一千克,1.5,3.0,5.0,3.5,4.5,3.5/);1stvariable
v1(/1.0,2.0,4.0,7.0,5.0,5.0,4.5/);2ndvariable
mdimsizes(v1);#observations
n2;#variables
k2;#clusters(userspecified)
xnew((/n,m/),typeof(v1),"No_FillValue")
x(0,:)v0
x(1AS136钢材多少钱一千克,:)v1
clcntrkmeans_as136(x,k,False);usedefaultoptions
print(clcntr);(1.25,1.5)and(3.9,5.1)
Aneditedversionoftheoutputfollows:
Variable:clcntr
Type:float
TotalSize:16bytes
4values
NumberofDimensions:2
Dimensionsandsizes:[2]x[2](kcX(:,{-30:30},:);x(time,lat,lon)
;reorderviaNCL'snameddimensionreordering
xrx(lat|:,lon|:,time|:);make'time'(observations;M)therightmostdimension
;thelat,lonarethe'variables'(N)
k3;#clusters(userspecified)
optTrue
opt@iseed1
clcntrkmeans_as136(xr,k,opt);inputthereorderedarray
:;clcntr(3,nlat,mlon)
delete(xr);deleteifnolongerneeded(notnecessary)苏州东锜公司下属业务部、热处理部、机加工部,财务部、运输部、仓储部(自备货厂、吊车、行车、自动激光切割、半成品),免费为用户提供装卸一条龙服务。多年以来,东锜模具钢产品与周到服务都深受广大模具厂商所认可,亦为国内模具钢材同行所瞩目,是苏州模具行业协会成员单位与江苏省模具工业协会成员单位。欢迎新老客户来电垂询,来厂参观。
本文部分内容来源于网络,我们仅作为信息分享。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌抄袭侵权/违法违规的内容,请发送邮件至tokaits@163.com举报,一经查实,本站将立刻删除。
下一篇:不锈钢630材料价格查询_钢材硬度