# 09.2 多项式回归法拟合复合函数曲线

## 9.2 用多项式回归法拟合复合函数曲线⚓︎

### 9.2.1 用四次多项式拟合⚓︎

    num_input = 4
num_output = 1
params = HyperParameters(num_input, num_output, eta=0.2, max_epoch=10000, batch_size=10, eps=1e-3, net_type=NetType.Fitting)


......
9899 99 0.004994434937236122
9999 99 0.0049819495247358375
W= [[-0.70780292]
[ 5.01194857]
[-9.6191971 ]
[ 6.07517269]]
B= [[-0.27837814]]


......
99899 99 0.004685711600240152
99999 99 0.005299305272730845
W= [[ -2.18904889]
[ 11.42075916]
[-19.41933987]
[ 10.88980241]]
B= [[-0.21280055]]


### 9.2.2 用六次多项式拟合⚓︎

999 99 0.005154576065966749
1999 99 0.004889156300531125
......
48999 99 0.0047460241904710935
49999 99 0.004669517756696059
W= [[-1.46506264]
[ 6.60491296]
[-6.53643709]
[-4.29857685]
[ 7.32734744]
[-0.85129652]]
B= [[-0.21745171]]


### 9.2.3 用八次多项式拟合⚓︎

......
49499 99 0.004086918553033752
49999 99 0.0037740488283595657
W= [[ -2.44771419]
[  9.47854206]
[ -3.75300184]
[-14.39723202]
[ -1.10074631]
[ 15.09613263]
[ 13.37017924]
[-15.64867322]]
B= [[-0.16513259]]


......
998999 99 0.0015935143877633367
999999 99 0.0016124984420510522
W= [[  2.75832935]
[-30.05663986]
[ 99.68833781]
[-85.95142109]
[-71.42918867]
[ 63.88516377]
[104.44561608]
[-82.7452897 ]]
B= [[-0.31611388]]


ch09, Level3