各位高手，兄弟遇到了一个困难，来此请求赐教啊！请多多帮助！

现在有两组数据：

y=[6.0430
    6.0334
    6.0238
    6.0142
    6.0046
    5.9951
    5.9855
    5.9758
    5.9662
    5.9566
    5.9469
    5.9372
    5.9276
    5.9178
    5.9081
    5.8984
    5.8887
    5.8789
    5.8691
    5.8593
    5.8496
    5.8397
    5.8299
    5.8201
    5.8103
    5.8004
    5.7906
    5.7807
    5.7708
    5.7609
    5.7510
    5.7410
    5.7310
    5.7211
    5.7111
    5.7010
    5.6910
    5.6809
    5.6709
    5.6607
    5.6506
    5.6404
    5.6302
    5.6199
    5.6097
    5.5994
    5.5890
    5.5785
    5.5681
    5.5576
    5.5471
    5.5364
    5.5258
    5.5151
    5.5044
    5.4935
    5.4827
    5.4717
    5.4607
    5.4496
    5.4385
    5.4272
    5.4159
    5.4046
    5.3931
    5.3815
    5.3699
    5.3582
    5.3464
    5.3345
    5.3225
    5.3104
    5.2982
    5.2860
    5.2736
    5.2611
    5.2485
    5.2357
    5.2230
    5.2101
    5.1970
    5.1838
    5.1706
    5.1571
    5.1436
    5.1300
    5.1162
    5.1023
    5.0883
    5.0741
    5.0597
    5.0453
    5.0307
    5.0160
    5.0011
    4.9861
    4.9709
    4.9556
    4.9400
    4.9244
    4.9086
    4.8926
    4.8764
    4.8602
    4.8437
    4.8270
    4.8102
    4.7932
    4.7761
    4.7587
    4.7411
    4.7234
    4.7054
    4.6874
    4.6690
    4.6504
    4.6317
    4.6127
    4.5936
    4.5742
    4.5545
    4.5348
    4.5147
    4.4944
    4.4739
    4.4532
    4.4322
    4.4109
    4.3894
    4.3676
    4.3456
    4.3232
    4.3007
    4.2779
    4.2547
    4.2313
    4.2076
    4.1835
    4.1591
    4.1345
    4.1095
    4.0842
    4.0585
    4.0325
    4.0061
    3.9794
    3.9523
    3.9249
    3.8969
    3.8686
    3.8399
    3.8108
    3.7812
    3.7512
    3.7207
    3.6897
    3.6582
    3.6263
    3.5937
    3.5607
    3.5269
    3.4927
    3.4579
    3.4223
    3.3862
    3.3494
    3.3118
    3.2735
    3.2345
    3.1946
    3.1538
    3.1121
    3.0696
    3.0260
    2.9813
    2.9356
    2.8888
    2.8406
    2.7911
    2.7402
    2.6878
    2.6337
    2.5778
    2.5202
    2.4603
    2.3982
    2.3336
    2.2661
    2.1956
    2.1215
    2.0434
    1.9605
    1.8722
    1.7773
    1.6742
    1.5606
    1.4328
    1.2849
    1.1036
    0.8539
         0]
x =[0.3517
    0.3549
    0.3581
    0.3614
    0.3646
    0.3679
    0.3711
    0.3744
    0.3776
    0.3808
    0.3841
    0.3873
    0.3906
    0.3938
    0.3970
    0.4003
    0.4035
    0.4068
    0.4100
    0.4133
    0.4165
    0.4197
    0.4230
    0.4262
    0.4295
    0.4327
    0.4360
    0.4392
    0.4424
    0.4457
    0.4489
    0.4522
    0.4554
    0.4586
    0.4619
    0.4651
    0.4684
    0.4716
    0.4749
    0.4781
    0.4813
    0.4846
    0.4878
    0.4911
    0.4943
    0.4975
    0.5008
    0.5040
    0.5073
    0.5105
    0.5138
    0.5170
    0.5202
    0.5235
    0.5267
    0.5300
    0.5332
    0.5364
    0.5397
    0.5429
    0.5462
    0.5494
    0.5526
    0.5559
    0.5591
    0.5624
    0.5656
    0.5689
    0.5721
    0.5753
    0.5786
    0.5818
    0.5851
    0.5883
    0.5915
    0.5948
    0.5980
    0.6013
    0.6045
    0.6078
    0.6110
    0.6142
    0.6175
    0.6207
    0.6240
    0.6272
    0.6305
    0.6337
    0.6369
    0.6402
    0.6434
    0.6467
    0.6499
    0.6531
    0.6564
    0.6597
    0.6629
    0.6661
    0.6694
    0.6726
    0.6758
    0.6791
    0.6823
    0.6855
    0.6888
    0.6921
    0.6953
    0.6985
    0.7018
    0.7050
    0.7082
    0.7115
    0.7147
    0.7180
    0.7212
    0.7245
    0.7277
    0.7309
    0.7342
    0.7374
    0.7406
    0.7439
    0.7472
    0.7504
    0.7537
    0.7569
    0.7601
    0.7634
    0.7666
    0.7698
    0.7731
    0.7764
    0.7796
    0.7828
    0.7861
    0.7893
    0.7925
    0.7958
    0.7990
    0.8022
    0.8055
    0.8088
    0.8120
    0.8152
    0.8185
    0.8217
    0.8249
    0.8282
    0.8314
    0.8346
    0.8379
    0.8412
    0.8444
    0.8476
    0.8509
    0.8541
    0.8573
    0.8606
    0.8638
    0.8671
    0.8704
    0.8736
    0.8768
    0.8801
    0.8833
    0.8865
    0.8898
    0.8930
    0.8963
    0.8995
    0.9028
    0.9060
    0.9092
    0.9125
    0.9157
    0.9189
    0.9222
    0.9255
    0.9287
    0.9319
    0.9352
    0.9384
    0.9416
    0.9449
    0.9481
    0.9513
    0.9546
    0.9579
    0.9611
    0.9643
    0.9676
    0.9708
    0.9741
    0.9773
    0.9805
    0.9838
    0.9871
    0.9903
    0.9935
    0.9968
    1.0000]
想给出一个函数y=y(x), 什么函数形式都可以，但要求必须满足当 x--->1时，y收敛到0。我曾经用命令polyfit(x,y,n)给出个关于x的n阶多项式，但是系统告诉我因为有0（Warning:Divided by zero)，所以没有办法算.想了很多办法都没有给出来啊。请高手指教！感谢ing!!!!