<p>在代码中:</p>
<pre><code>df['U2'] = np.power(2,df['Speed mph'])
</code></pre>
<p>np.power函数的应用与预期不同,它将第一行设置为1073741824,其余行为零</p>
<pre><code>print[df]
Year Speed mph Means of attaining speed U2
0 1830 30 Railroad 1073741824
1 1905 130 Rairoad 0
2 1930 400 Airplane 0
3 1947 760 Airplane 0
4 1952 1500 Airplane 0
5 1969 25000 Spaceship 0
</code></pre>
<p>将该行修改为:</p>
<pre><code>df['U2'] = df['Speed mph'].apply(lambda x: x * x)
</code></pre>
<p>或</p>
<pre><code>df['U2'] = df['Speed mph'].apply(np.square)
</code></pre>
<p>因此df变成:</p>
<pre><code> Year Speed mph Means of attaining speed U2
0 1830 30 Railroad 900
1 1905 130 Rairoad 16900
2 1930 400 Airplane 160000
3 1947 760 Airplane 577600
4 1952 1500 Airplane 2250000
5 1969 25000 Spaceship 625000000
</code></pre>
<p>最后</p>
<pre><code>r_value=0.46 p_value=0.36
</code></pre>
<p>现在,一切都很好:)</p>