关于隐函数非线性回归的问题

csu527

请教下各位大大 ，我用a1 + a2*x + a3*y + a4*x^2 + a5*x*y + a6*y^2 + a7*x^3 + a8*x^2*y + a9*x*y^2 + a10*y^3=0;去拟合一条曲线，拟合的结果显示很好，但是我用拟合得到的参数方程来画隐函数曲线，画出来的曲线跟原来的怎么一点都不像啊！这是怎么回事啊？

dingd

把你的数据和结果贴上来看看。

csu527

原帖由 dingd 于 2009-5-6 09:03 发表

                               
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把你的数据和结果贴上来看看。

x   y
-73.00000000000003  87.00000000000003
-72.6667132237097 86.00000000000003
-72.33321986000075 85.00000000000003
-71.9995636509795 84.00000000000003
-71.6644303442475 83.00000000000003
-71.32401920661744 82.00000000000003
-70.97028481355002 81.00000000000003
-70.59040283796998 80.00000000000003
-70.17331653040213 79.00000000000003
-69.71800558521505 78.00000000000003
-69.23152812581668 77.00000000000003
-68.71844193423556 76.00000000000003
-68.17559940986428 75.00000000000003
-67.59967040764278 74.00000000000003
-66.99999999999997 73.00000000000003
-66.4002626760676 72.00000000000003
-65.82389732482565 71.00000000000003
-65.27883883728177 70.00000000000003
-64.75692142504832 69.00000000000003
-64.24301165866214 68.00000000000003
-63.72065789740814 67.00000000000001
-63.173383446691695 66.00000000000003
-62.58825379108689 65.00000000000003
-61.96145359289765 64.00000000000003
-61.2965199833401 63.00000000000002
-60.596951179160136 62.00000000000002
-59.867025712079105 61.00000000000002
-59.1182013449931 60.000000000000036
-58.361279919944785 59.00000000000002
-57.588186874797366 58.00000000000001
-56.77305385433447 57.00000000000003
-55.89625730727243 56.00000000000002
-54.961453592897676 55.00000000000002
-53.98851646715453 54.00000000000003
-52.99728077151732 53.00000000000003
-51.99949673468989 52.00000000000002
-50.999933083710424 51.00006691628958
-50.00000000000002 50.0005032653101
-49.00000000000001 49.002719228482704
-47.99999999999999 48.01155044913505
-46.99999999999998 47.038982756122856
-46.00000000000001 46.10595865590018
-45.00000000000001 45.23571045002832
-44.00000000000002 44.43874216688041
-43.00000000000001 43.703043667639456
-42.000000000000036 43.0005032653101
-40.99999999999999 42.29974247713284
-39.99999999999999 41.5727413659651
-39.00000000000001 40.8027690407845
-37.99999999999999 39.99734768780692
-36.99999999999999 39.185747426370085
-36.00000000000001 38.39143145541529
-35.00000000000001 37.60850162829517
-34.00000000000001 36.81374930831987
-32.99999999999999 35.999933083710445
-32.00006691628956 35.185747426370085
-31.00050326531008 34.38877914322218
-30.002719228482682 33.59701809544971
-29.011483532845467 32.77526981750711
-28.03847949081277 31.896693656292953
-27.103239427417478 30.961520509187267
-26.224226917182833 29.988516467154554
-25.400262676067626 28.99728077151734
-24.59980424022195 27.999496734689956
-23.776276348127247 26.999933083710445
-22.89947980106519 26.00000000000003
-21.973004042032706 25.000000000000014
-21.026995957967294 24.00000000000003
-20.10058711522438 23.00000000000003
-19.224226917182833 22.000000000000014
-18.402981904550302 21.000000000000014
-17.611724122087907 20.000000000000014
-16.817038718402173 19.000000000000043
-16.011986798155533 18
-15.226946145665515 17.000000000000014
-14.503569019774687 16.000000000000014
-13.860227768755365 15.000000000000014
-13.281558065764443 14.000000000000028
-12.732644695563685 13.000000000000014
-12.178754987367462 12.000000000000014
-11.59973732393236 11.000000000000028
-10.99728077151731 10.000066916289612
-10.388275877912086 9.000570181599699
-9.7826986055302 8.003222493792748
-9.16404896072924 7.014269677617719
-8.493711751742623 6.050466288968309
-7.736790326694319 5.144438146712929
-6.885210123447479 4.338949877445799
-5.958801280704563 3.662969084063221
-4.988013201844446 3.103306343707075
-3.997213855227756 2.600240589242489
-2.999496734689913 2.07558247623956
-1.999933083710424 1.47007212014725
-1 0.767512043764469
0  0

csu527

原帖由 dingd 于 2009-5-6 09:03 发表

                               
登录/注册后可看大图

把你的数据和结果贴上来看看。

麻烦主任帮我看看咯