在机器学习中，最后要计算混淆矩阵，常用的函数有:
- table
- confusionMatrix
下面以前馈神经网络为例来说明:
代码语言：javascript复制> library("RSNNS")
载入需要的程辑包：Rcpp
> library("reshape")
> #example data and code from nnet function examples
> ir<-rbind(iris3[,,1],iris3[,,2],iris3[,,3])
> targets<-class.ind( c(rep("s", 50), rep("c", 50), rep("v", 50)) )
> samp<-c(sample(1:50,25), sample(51:100,25), sample(101:150,25))
> ir1<-nnet(ir[samp,], targets[samp,], size = 2, rang = 0.1,decay = 5e-4, maxit = 20000)
# weights: 19
initial value 57.066913
iter 10 value 49.626816
iter 20 value 37.715215
iter 30 value 37.621041
iter 40 value 36.061689
iter 50 value 26.406216
iter 60 value 26.358554
iter 70 value 26.304323
iter 80 value 26.037665
iter 90 value 9.566053
iter 100 value 2.356429
iter 110 value 2.330607
iter 120 value 2.322488
iter 130 value 2.320141
iter 140 value 2.319636
iter 150 value 2.319221
iter 160 value 2.318749
iter 170 value 2.318371
iter 180 value 2.318266
iter 190 value 2.318228
iter 200 value 2.318209
final value 2.318200
converged
>
> #####预测和混淆矩阵
> predictions = predict(ir1,ir[-samp,])
> confusionMatrix(targets[-samp,],predictions)
predictions
targets 1 2 3
1 23 0 2
2 0 25 0
3 0 0 25
> table(targets[-samp,],predictions)
predictions
0.00403377540307142 0.00403564641047421 0.00403570768092494
0 1 1 1
1 0 0 0
predictions
0.00403605256654588 0.00403630750101855 0.00403641366388631
0 1 1 1
1 0 0 0
predictions
0.00403692649836654 0.00403786506435831 0.00403825215906985
0 1 1 1
1 0 0 0
predictions
0.00403917030652169 0.00404567897588413 0.00404798236102891
0 1 1 1
1 0 0 0
predictions
0.00404893293411496 0.00405574340716223 0.00405836767997865
0 1 1 1
1 0 0 0
predictions
0.00406710814346536 0.0040701247774299 0.00408251547829692
0 1 1 1
1 0 0 0
predictions
0.00412797392700353 0.00413594795412441 0.00416158973397778
0 1 1 1
1 0 0 0
predictions
0.00416814984429532 0.00417286744332778 0.00417362395573791
0 1 1 1
1 0 0 0
predictions
0.00417918626716218 0.00418009383086655 0.00419874938914643
0 1 1 1
1 0 0 0
predictions
0.00421981780492951 0.00423152295291501 0.00423193441275875
0 1 1 1
1 0 0 0
predictions
0.00424849342991043 0.00430144238200611 0.00436038633080191
0 1 1 1
1 0 0 0
predictions
0.00439684626994913 0.00442242048735527 0.00458507759207128
0 1 1 1
1 0 0 0
predictions
0.00464975407207362 0.00470506382077678 0.00499347960880904
0 1 1 1
1 0 0 0
predictions
0.00518953025588815 0.00519933029061764 0.0052814348113268
0 1 1 1
1 0 0 0
predictions
0.00558431531798989 0.00595926604148108 0.00600552141490726
0 1 1 1
1 0 0 0
predictions
0.006915891368665 0.00759615927656485 0.00829442420831341
0 1 1 1
1 0 0 0
predictions
0.00844447207060653 0.00856276324301847 0.00859179660930141
0 1 1 1
1 0 0 0
predictions
0.00860201009135315 0.00860601920084842 0.00863743659341979
0 1 1 1
1 0 0 0
predictions
0.00864140831518805 0.00864888074285641 0.0086521847462041
0 1 1 1
1 0 0 0
predictions
0.00865344584729278 0.00865493915617089 0.00865849335003599
0 1 1 1
1 0 0 0
predictions
0.00865922177678391 0.00867566062753029 0.00867896771232396
0 1 1 1
1 0 0 0
predictions
0.00868312254593745 0.0086859108866324 0.00869537547110483
0 1 1 1
1 0 0 0
predictions
0.00869670887342119 0.00869864378012673 0.00870865406145213
0 1 1 1
1 0 0 0
predictions
0.00871389523727452 0.00872021311903557 0.00872345360284301
0 1 1 1
1 0 0 0
predictions
0.00872387327365123 0.0102323682173483 0.0105757335442083
0 1 1 1
1 0 0 0
predictions
0.0119529981550286 0.0124141057613249 0.0126325452293645
0 1 1 1
1 0 0 0
predictions
0.012833440812906 0.0131525079576031 0.0132079822099268
0 1 1 1
1 0 0 0
predictions
0.0133337996928362 0.013367781106834 0.0134762990363478
0 1 1 1
1 0 0 0
predictions
0.0135442965605383 0.0135810901988006 0.0136761283209433
0 1 1 1
1 0 0 0
predictions
0.0136774878496964 0.0137379609469079 0.0137420907754618
0 1 1 1
1 0 0 0
predictions
0.0144442987763459 0.0156778113343933 0.0156869197995948
0 1 1 1
1 0 0 0
predictions
0.015757440975887 0.0158959078604056 0.0160117612659147
0 1 1 1
1 0 0 0
predictions
0.0162355415267055 0.0162791795628935 0.0163093245777637
0 1 1 1
1 0 0 0
predictions
0.0164781461796075 0.0165250129752519 0.0165891344883245
0 1 1 1
1 0 0 0
predictions
0.0166851724888285 0.0167620382615496 0.0171497596692717
0 1 1 1
1 0 0 0
predictions
0.0171671595863806 0.017252328578273 0.0172882467881398
0 1 1 1
1 0 0 0
predictions
0.0173186417658541 0.0173985447394498 0.0175807065809304
0 1 1 1
1 0 0 0
predictions
0.0176783539787929 0.01847141318664 0.0185753050370508 0.018662823048094
0 1 1 1 1
1 0 0 0 0
predictions
0.0188427947522583 0.0194803512595932 0.0196257828944348
0 1 1 1
1 0 0 0
predictions
0.023191551665019 0.0250189206726615 0.0274317187789071
0 1 1 1
1 0 0 0
predictions
0.027449845321461 0.0274535377434953 0.0274561647040755
0 1 1 1
1 0 0 0
predictions
0.0274671028942351 0.027474213631734 0.0274754708307417
0 1 1 1
1 0 0 0
predictions
0.0275215489790161 0.0275253497277815 0.0276609180875735
0 1 1 1
1 0 0 0
predictions
0.027661232198567 0.0278704168563232 0.0279312670107136
0 1 1 1
1 0 0 0
predictions
0.0281167604326715 0.0281541170972859 0.028388668868556
0 1 1 1
1 0 0 0
predictions
0.028890862721736 0.0288985222475749 0.0291613373288461
0 1 1 1
1 0 0 0
predictions
0.0321499794319152 0.0325145751040805 0.0347032558252448
0 1 1 1
1 0 0 0
predictions
0.0349570256697902 0.0670718767155293 0.112184565533575
0 1 1 1
1 0 0 0
predictions
0.118523381829258 0.149732846270052 0.156742558680462 0.246236986571863
0 1 0 1 0
1 0 1 0 1
predictions
0.375634421026004 0.594721005324995 0.747773548238688 0.842525603401285
0 1 0 1 0
1 0 1 0 1
predictions
0.849297998894218 0.867686231396129 0.8824232162991 0.935631524840151
0 1 0 0 0
1 0 1 1 1
predictions
0.967245893542904 0.967686698818511 0.967955157358171 0.970082509157067
0 0 0 0 0
1 1 1 1 1
predictions
0.97044659702987 0.97335595682131 0.973513712122999 0.973597441388668
0 0 0 0 0
1 1 1 1 1
predictions
0.9741089604963 0.974296709168098 0.974313480219197 0.97453043045748
0 0 0 0 0
1 1 1 1 1
predictions
0.97457673836994 0.974773168687682 0.974809586221223 0.974930051689301
0 0 0 0 0
1 1 1 1 1
predictions
0.974945619426515 0.974982681274091 0.97498434260433 0.974986907735066
0 0 0 0 0
1 1 1 1 1
predictions
0.974993162694631 0.975003012935513 0.975008716416213 0.975034560958276
0 0 0 0 0
1 1 1 1 1
predictions
0.977991144171454 0.981119083566536 0.981811727613766 0.982048875519914
0 0 0 0 0
1 1 1 1 1
predictions
0.982141056136557 0.982846103949432 0.982933087841843 0.983095460654908
0 0 0 0 0
1 1 1 1 1
predictions
0.983166726405304 0.983193842721315 0.98322589142289 0.983301906510452
0 0 0 0 0
1 1 1 1 1
predictions
0.983317440019031 0.983663903576428 0.983732666104228 0.9838186155581
0 0 0 0 0
1 1 1 1 1
predictions
0.98387602356082 0.984069261555991 0.984096285201701 0.984135411879867
0 0 0 0 0
1 1 1 1 1
predictions
0.984336191216582 0.984440225557155 0.984564646746689 0.98462804833628
0 0 0 0 0
1 1 1 1 1
predictions
0.984636238917024 0.985888119718936 0.989343984979299 0.99111550527635
0 0 0 0 0
1 1 1 1 1
predictions
0.991183977831676 0.991249360303782 0.992224304664137 0.992508176255563
0 0 0 0 0
1 1 1 1 1
predictions
0.992988966531712 0.993048210832194 0.993178174597829 0.993250413896391
0 0 0 0 0
1 1 1 1 1
predictions
0.993328226044017 0.993378955615131 0.99348242946841 0.993551717508145
0 0 0 0 0
1 1 1 1 1
predictions
0.993557187071166 0.99363007375035 0.993692579864391 0.993734588950939
0 0 0 0 0
1 1 1 1 1
