EasyKrig30的说明文档kriging插值Word文件下载.docx
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1.1GeneralInformation
1.1.1Aboutkriging
1.1.2Briefdescriptionsofeasy_krig3.0
1.2Gettingstarted
1.2.1Operatingsystems
1.2.2Down-loadtheprogram
1.2.3Quickstart
2.DataProcessingStages
2.1DataPreparation
2.2Semi-variogram
2.3Kriging
2.4Visualization
2.5SavingKrigingResults
3.Examples
3.1Example1:
AnAerialImageofZooplanktonAbundanceData
3.2Example2:
AVerticalSectionofSalinityData–AnAnisotropicDataset
3.3Example3:
BatchProcessofPressure(dbar)atDifferentPotentialDensityLayers
3.4Example4:
3-DimensionalTemperatureData
4.References
1.Introduction
1.1GeneralInformation
Thissectionprovidesabrieftheoreticalbackgroundforkriging.Iftheuser(s)isnotinterestedinthetheoreticalbackground,he/shecanskipthissectionandgotosection1.1.2directly.
KrigingisatechniquethatprovidestheBestLinearUnbiasedEstimatoroftheunknownfields(JournelandHuijbregts,1978;
Kitanidis,1997).ItisalocalestimatorthatcanprovidetheinterpolationandextrapolationoftheoriginallysparselysampleddatathatareassumedtobereasonablycharacterizedbytheIntrinsicStatisticalModel(ISM).AnISMdoesnotrequirethequantityofinteresttobestationary,i.e.itsmeanandstandarddeviationareindependentofposition,butratherthatitscovariancefunctiondependsontheseparationoftwodatapointsonly,i.e.
E[(z(x)–m)(z(x’)–m)]=C(h),
(1)
wheremisthemeanofz(x)andC(h)isthecovariancefunctionwithlagh,withhbeingthedistancebetweentwosamplesxandx’:
h=||x–x’||=
(2)
AnotherwaytocharacterizeanISMistouseasemi-variogram,
=0.5*E[(z(x)–z(x’))2].(3)
Therelationbetweenthecovariancefunctionandthesemi-variogramis
=C(0)–C(h).(4)
Thekrigingmethodistofindalocalestimateofthequantityataspecifiedlocation,
.ThisestimateisaweightedaverageoftheNadjacentobservations:
(5)
Theweightingcoefficients
canbedeterminedbasedontheminimumestimationvariancecriterion:
(6)
subjecttothenormalizationcondition
.(7)
Notethatwedon’tknowtheexactvalueat
butwearetryingtofindapredictedvaluethatprovidestheminimumestimationvariance.Theresultantkrigingequationcanbeexpressedas
(8)
whereistheLagrangiancoefficient.Inaddition,wehavereplacedthecovariancefunctionwiththenormalizedcovariancefunction[normalizedbyC(0)].Equivalently,byusingEq.(4),thekrigingequationcanalsobeexpressedintermsofthesemi-variogramas
(9)
wherewehaveusednormalizedsemi-variogram,i.e.,semi-variogramnormalizedbyC(0)aswedidinderivingEq.(8).
Havingobtainedtheweightingcoefficients(
)andtheLagrangiancoefficient(
)bysolvingeitherEq.(8)OREq.(9),thekrigingvariance,Eq.(6),canbeexpressedas:
.(10)
TheaboveequationsarethebasisoftheEasykrigsoftwarepackage.
1.1.2BriefdescriptionofEasyKrig3.0
TheEasyKrigprogrampackageusesaGraphicalUserInterface(GUI).ItrequiresMATLAB5.3orhigherwithorwithoutoptimizationtoolbox(seesection2.2)andconsistsoffivecomponents,orprocessingstages:
(1)datapreparation,
(2)variogramcomputation,(3)kriging,(4)visualizationand(5)savingresults.Itallowstheusertoprocessanisotropicdata,selectanappropriatemodelfromalistofvariogrammodels,andachoiceofkrigingmethods,aswellasassociatedkrigingparameters,whicharealsocommonfeaturesoftheotherexistingsoftwarepackages.Oneofthemajoradvantagesofthisprogrampackageisthattheprogramminimizestheusers'
requirementsto"
guess"
theinitialparametersandautomaticallygeneratestherequireddefaultparameters.Inaddition,becauseitusesaGUI,themodificationsfromtheinitialparametersettingscanbeeasilyperformed.Anotherfeatureofthisprogrampackageisthatithasabuilt-inon-linehelplibrarythatallowstheusertoobtainthedescriptionsoftheuseofparametersandoperationoptionseasily.
ThecurrentEasyKrig3.0istheupgradedversionofthepreviousversion(EasyKrig2.1).Inadditiontohavingcorrectedsomeprogrammingerrorsinthepreviousversion(mostlyGUIrelatederrors),therearemanynewfeaturesincludedinthecurrentversion:
∙MatlabVersion6.xand7.0(testedunderWindows)compatible
∙Capableofhandling3-Ddata
∙Enhancedbatchfileprocessingcapability
∙Moreflexibleinloadinginputdataandsavingoutputdata
∙Capableofhandlingthecustomizedgridfile
∙Moreexampleswithdetailedstepbystepinstructionsareprovidedtoallowuser(s)tomasterthefunctionalityofthesoftwarepackagemorequicklyandeasily.
AlthoughthissoftwarepackagelackssomeabilitiessuchasCo-kriging,itdoesprovideaconvenienttoolforgeostatisticalapplicationsandshouldalsohelpscientistsfromotherfields.
ForpeoplewhodonotwanttouseGUIbutonlyinterestedinfunction-basedm-filescangotoadifferentwebsitethatprovidesafunction-basedm-fileKrigingpackage(globec.whoi.edu/software/kriging/V3/intro_v3.html)developedbyCarolineLafleurandYvesGratton,INRS-Océ
anologie,UniversitduQubecRimouski.
1.2GettingStarted
ThesoftwarewasoriginallydevelopedunderMATLAB6.5onaPC(windows2000)andintendedtobecomputerand/oroperatingsystemindependent.Theprogramhasbeentestedonvariousmachines(PC,Macintosh,andSunWorkstation)andoperatingsystems(windows2000/Xp,Linux)andperformsfine.
1.2.2Down-loadtheprogram
TheuserneedstodownloadthecompressedfilefromGLOBECwebsitefirst,theURLis
ftp:
//globec.whoi.edu/pub/software/kriging/easy_krig/V3.0.1/
andthecompressedfileis
Windows95/98/NT/2000/XP,
MacintoshandLinux:
easy_krig30.zip
Unix:
easy_krig30.tar.gz
Afterhavingdownloadedthefile,theuserneedstouncompressthefile.Adirectoryofeasy_krig3.0willbecreatedandyouarereadytoruntheprogram.
StartMATLABandgotothedesignatedeasy_krig3.0homedirectory.Justtype“startkrig”intheMATLABcommandwindow,awindowwillpopup.Thiswindowisthebasewindow,calledtheNavigatorwindow.TheMenubarinthiswindowcontainsmanyoptionsyoucanchoose.Nowyouarereadytomoveon.
Note:
YoucanaddthekriginghomedirectorytotheMatlabsearchpathandruntheprogramfromotherdirectories.However,youhavetomakesurethattherearenofunctionsofyourownhavingthesamenamesasthoseusedforeasy_krig3.0.Sincetheprogramwillallowyoutoloadandsavefilesusingafilebrowser,itisrecommendedthatyouruntheprogramundertheeasy_krig3.0homedirectory.
Theprogramprovidesafullon-linehelpfunctionthatprovidesthedescriptionstheuseofalmostalloftheselectablefunctions,options,andparameters.Itisquiteself-explanatoryandeasytouse.
2.DataProcessingStages
Thereareseveraldataprocessingstages(tasks)thatareselectablefromtheMenubaronthetopoftheNavigatorwindow,aswellasothertaskwindows.Byselectingorclickingonanyofthetasks,awindowcorrespondingtotheselectedtaskwillpopup.OneachtaskwindowincludingtheNavigatorwindow,thedescriptionsandexplanationsofeveryoptionandselectionineachtaskwindowcanbefoundbyclickonthe“Help”optionontheMenubar.Onanyofthetaskwindows,clickingonthe“Navigator”button,orselecting“Navigator”fromtheMenubarwillbringbacktheNavigatorwindow.
2.1DataPreparation
Selecting“LoadData”from“Task”ontheMenubarofanywindowleadstotheDataPreparationwindow.Clickonthe“'
Load”buttonorselect“Load”fromtheMenubartoloadtherawdatafile.Theformatofthedatafileshouldbea3-columnASCIIfilefor2Ddataand4-columnASCIIfilefor3Ddata.Commentsatthebeginningofthedatafilewillnotaffectthedataaslongaseachcommentlinebeginswithapercentagesymbol“%”.
User(s)canprovidetheirownm-filetoloadthedatabyusing“ExternalProgram”optionintheDataPreparationwindow.ThisfunctionallowstheusertogeneratetheinputdatadirectlyfromtherawdatainsteadofgeneratinganASCIIfilethatisrequiredbytheEasykrig3.0.Therequiredformatfortheinputandoutputparametersbyusinganexternalprogramcanbefoundbyclickingonthe“Help”fromtheMenubarandselecting“ExternalProgram”.
Onecansettheotherparameterssuchasreductionfactor(orjustacceptdefaultsettings)beforeloadingthefile.Afterthefileisloaded,iftheuserwantstochangetheother(default)settings,suchasdatafilter,he/shecandosoandthenclickon“Apply”pushbuttonaftertheparametershavebeenset.Thedifferencebetween“Load'
”and“Apply”isthatthelatteroperationisfastersinceitw