原始數據:
datasets.data[0:2]
array([[1.799e+01, 1.038e+01, 1.228e+02, 1.001e+03, 1.184e-01, 2.776e-01,
3.001e-01, 1.471e-01, 2.419e-01, 7.871e-02, 1.095e+00, 9.053e-01,
8.589e+00, 1.534e+02, 6.399e-03, 4.904e-02, 5.373e-02, 1.587e-02,
3.003e-02, 6.193e-03, 2.538e+01, 1.733e+01, 1.846e+02, 2.019e+03,
1.622e-01, 6.656e-01, 7.119e-01, 2.654e-01, 4.601e-01, 1.189e-01],
[2.057e+01, 1.777e+01, 1.329e+02, 1.326e+03, 8.474e-02, 7.864e-02,
8.690e-02, 7.017e-02, 1.812e-01, 5.667e-02, 5.435e-01, 7.339e-01,
3.398e+00, 7.408e+01, 5.225e-03, 1.308e-02, 1.860e-02, 1.340e-02,
1.389e-02, 3.532e-03, 2.499e+01, 2.341e+01, 1.588e+02, 1.956e+03,
1.238e-01, 1.866e-01, 2.416e-01, 1.860e-01, 2.750e-01, 8.902e-02]])
scaler = StandardScaler(copy=False)
scaler.fit(datasets.data)
datasets.data[0:2]
array([[1.799e+01, 1.038e+01, 1.228e+02, 1.001e+03, 1.184e-01, 2.776e-01,
3.001e-01, 1.471e-01, 2.419e-01, 7.871e-02, 1.095e+00, 9.053e-01,
8.589e+00, 1.534e+02, 6.399e-03, 4.904e-02, 5.373e-02, 1.587e-02,
3.003e-02, 6.193e-03, 2.538e+01, 1.733e+01, 1.846e+02, 2.019e+03,
1.622e-01, 6.656e-01, 7.119e-01, 2.654e-01, 4.601e-01, 1.189e-01],
[2.057e+01, 1.777e+01, 1.329e+02, 1.326e+03, 8.474e-02, 7.864e-02,
8.690e-02, 7.017e-02, 1.812e-01, 5.667e-02, 5.435e-01, 7.339e-01,
3.398e+00, 7.408e+01, 5.225e-03, 1.308e-02, 1.860e-02, 1.340e-02,
1.389e-02, 3.532e-03, 2.499e+01, 2.341e+01, 1.588e+02, 1.956e+03,
1.238e-01, 1.866e-01, 2.416e-01, 1.860e-01, 2.750e-01, 8.902e-02]])
scaler = StandardScaler(copy=False)
scaler.fit_transform(datasets.data)
array([[ 1.09706398, -2.07333501, 1.26993369, ..., 2.29607613,
2.75062224, 1.93701461],
[ 1.82982061, -0.35363241, 1.68595471, ..., 1.0870843 ,
-0.24388967, 0.28118999],
[ 1.57988811, 0.45618695, 1.56650313, ..., 1.95500035,
1.152255 , 0.20139121],
...,
[ 0.70228425, 2.0455738 , 0.67267578, ..., 0.41406869,
-1.10454895, -0.31840916],
[ 1.83834103, 2.33645719, 1.98252415, ..., 2.28998549,
1.91908301, 2.21963528],
[-1.80840125, 1.22179204, -1.81438851, ..., -1.74506282,
-0.04813821, -0.75120669]])
datasets.data[0:2]
[[ 1.09706398e+00 -2.07333501e+00 1.26993369e+00 9.84374905e-01
1.56846633e+00 3.28351467e+00 2.65287398e+00 2.53247522e+00
2.21751501e+00 2.25574689e+00 2.48973393e+00 -5.65265059e-01
2.83303087e+00 2.48757756e+00 -2.14001647e-01 1.31686157e+00
7.24026158e-01 6.60819941e-01 1.14875667e+00 9.07083081e-01
1.88668963e+00 -1.35929347e+00 2.30360062e+00 2.00123749e+00
1.30768627e+00 2.61666502e+00 2.10952635e+00 2.29607613e+00
2.75062224e+00 1.93701461e+00]
[ 1.82982061e+00 -3.53632408e-01 1.68595471e+00 1.90870825e+00
-8.26962447e-01 -4.87071673e-01 -2.38458552e-02 5.48144156e-01
1.39236330e-03 -8.68652457e-01 4.99254601e-01 -8.76243603e-01
2.63326966e-01 7.42401948e-01 -6.05350847e-01 -6.92926270e-01
-4.40780058e-01 2.60162067e-01 -8.05450380e-01 -9.94437403e-02
1.80592744e+00 -3.69203222e-01 1.53512599e+00 1.89048899e+00
-3.75611957e-01 -4.30444219e-01 -1.46748968e-01 1.08708430e+00
-2.43889668e-01 2.81189987e-01]]
copy的作用就是transform的時候是否需要進行進行備份,不修改原數據