MasteringMachineLearningwithR,2ndEdition-PacktPublishing(2017).epub

MasteringMachineLearningwithR,2ndEdition-PacktPublishing(2017).epub
Itisnotsoofteninlifethatyougetasecondchance.Irememberthatonlydaysafterwestoppededitingthefirstedition,Ikeptaskingmyself,"Whydidn'tI...?",or"WhattheheckwasIthinkingsayingitlikethat?",andonandon.Infact,thefirstprojectIstartedworkingonafteritwaspublishedhadnothingtodowithanyofthemethodsinthefirstedition.Imadeamentalnotethatifgiventhechance,itwouldgointoasecondedition.WhenIstartedwiththefirstedition,mygoalwastocreatesomethingdifferent,maybeevencreateaworkthatwasapleasuretoread,giventheconstraintsofthetopic.AfterallthefeedbackIreceived,IthinkIhitthemark.However,thereisalwaysroomforimprovement,andifyoutryandbeeverythingtoallpeople,youbecomenothingtoeverybody.I'mremindedofoneofmyfavoriteFrederickthegreatquotes,"Hewhodefendseverything,defendsnothing".So,I'vetriedtoprovideenoughoftheskillsandtools,butnotallofthem,togetareaderupandrunningwithRandmachinelearningasquicklyandpainlesslyaspossible.IthinkI'veaddedsomeinterestingnewtechniquesthatbuildonwhatwasinthefirstedition.Therewillprobablyalwaysbethedetractorswhocomplainitdoesnotofferenoughmathordoesnotdothis,that,ortheotherthing,butmyanswertothatistheyalreadyexist!Whyduplicatewhatwasalreadydone,andverywell,forthatmatter?Again,Ihavesoughttoprovidesomethingdifferent,somethingthatwouldkeepthereader'sattentionandallowthemtosucceedinthiscompetitivefield.BeforeIprovidealistofthechanges/improvementsincorporatedintothesecondedition,chapterbychapter,letmeexplainsomeuniversalchanges.Firstofall,Ihavesurrenderedinmyefforttofighttheusageoftheassignmentoperator＜-versusjustusing=.AsIsharedmoreandmorecodewithothers,IrealizedIwasoutonmyownusing=andnot＜-.ThefirstthingIdidwhenundercon 本软件ID:10288571