MatLab xcov problem

b = [2.885243315697212
   2.885242140769612
   2.885241040722891
   2.885240021403596
   2.885239107174130
   2.885238292082917
   2.885237577786640
   2.885236947994975
   2.885236397831325
   2.885235933531469
   2.885235507791045
   2.885235098554217
   2.885234718502994
   2.885234348524427
   2.885233973498498
   2.885233583464606
   2.885233183489066
   2.885232773469999
   2.885232352702702
   2.885231928466136
   2.885231503445336
   2.885231073413174
   2.885230632679641
   2.885230153416834
   2.885229657619761
   2.885229127644135
   2.885228547610220
   2.885227911766467
   2.885227202607179
   2.885226436750251
   2.885225656709870
   2.885224861752988
   2.885224047137096
   2.885223216703297
   2.885222371749751
   2.885221516636637
   2.885220645804195
   2.885219771686626
   2.885218921666667
   2.885218121620000
   2.885217346613546
   2.885216592066116
   2.885215861556556
   2.885215141603396
   2.885214431529589
   2.885213716516517
   2.885213001540756
   2.885212281513026
   2.885211556476476
   2.885210806497513
   2.885210036423576
   2.885209271440000
   2.885208521457711
   2.885207797337011
   2.885207112302697
   2.885206482286282
   2.885205927242757
   2.885205448266129
   2.885205063205384
   2.885204763172690
   2.885204544080000
   2.885204399074627
   2.885204305000000
   2.885204255000000
   2.885204245000000
   2.885204265000000
   2.885204300000000
   2.885204335000000
   2.885204360960000
   2.885204405000000
   2.885204440952381
   2.885204470000000
   2.885204485000000
   2.885204490000000
   2.885204475000000
   2.885204445000000
   2.885204440979125
   2.885204470000000
   2.885204510000000
   2.885204570993048
   2.885204651001001
   2.885204740000000
   2.885204815913173
   2.885204880000000
   2.885204941027944
   2.885204995000000
   2.885205055000000
   2.885205135000000
   2.885205256015936
   2.885205467075848
   2.885205782084168
   2.885206192043868
   2.885206713111223
   2.885207389180000
   2.885208245218688
   2.885209281318956
   2.885210487447552
   2.885211842348258
   2.885213342399800
   2.885214954585000
   2.885216659591634];

c = [2.885238983898076
   2.885238189173765
   2.885237394449455
   2.885236715302299
   2.885236151724911
   2.885235588148168
   2.885235171365908
   2.885234754583647
   2.885234362794264
   2.885233995995963
   2.885233629197632
   2.885233257455616
   2.885232885713600
   2.885232487412517
   2.885232062554486
   2.885231637696088
   2.885231168858261
   2.885230700020434
   2.885230220400259
   2.885229729997600
   2.885229239594309
   2.885228688056865
   2.885228136519420
   2.885227528559040
   2.885226864175436
   2.885226199790203
   2.885225402893897
   2.885224605997590
   2.885223791867157
   2.885222960502648
   2.885222129137817
   2.885221275281774
   2.885220421425731
   2.885219559795310
   2.885218690390595
   2.885217820987227
   2.885217034570871
   2.885216248154516
   2.885215497494732
   2.885214782590855
   2.885214067687398
   2.885213375890604
   2.885212684093810
   2.885211993893566
   2.885211305289831
   2.885210616685837
   2.885209915249088
   2.885209213812339
   2.885208518675669
   2.885207829838861
   2.885207141002053
   2.885206535338520
   2.885205929675235
   2.885205414886497
   2.885204990968462
   2.885204567050427
   2.885204372649141
   2.885204178248087
   2.885204040469169
   2.885203959309545
   2.885203878150011
   2.885203889450072
   2.885203900750134
   2.885203923310413
   2.885203957130256
   2.885203990950085
   2.885204019790241
   2.885204048630398
   2.885204074340320
   2.885204096920216
   2.885204119499982
   2.885204115819962
   2.885204112139943
   2.885204132420715
   2.885204176660510
   2.885204220900667
   2.885204317741193
   2.885204414581718
   2.885204535432627
   2.885204680291956
   2.885204825151270
   2.885204968350606
   2.885205111549942
   2.885205274219998
   2.885205456360986
   2.885205638503295
   2.885205942401886
   2.885206246300478
   2.885206697461177
   2.885207295884423
   2.885207894312677
   2.885208883508093
   2.885209872703508
   2.885211073725569
   2.885212486573232
   2.885213899425115
   2.885215597557245
   2.885217295689375
   2.885219085771134
   2.885220967801342
   2.885222849833701];

close all
figure

plot(1:numel(b), b);
hold on
plot(1:numel(c), c, 'r');

[crossCorr] = xcov(b, c);
[~, peakIndex] = max(crossCorr())
offset = peakIndex - length(b)