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<p>我有一个振荡数据如下图所示,并希望拟合一个正弦曲线。然而,我的结果是不正确的。在</p>
<p>我想要拟合到这条曲线的函数是:</p>
<pre><code>def radius (z,phi, a0, k0,):
Z = z.reshape(z.shape[0],1)
k = np.array([k0,])
a = np.array([a0,])
r0 = 110
rs = r0 + np.sum(a*np.sin(k*Z +phi), axis=1)
return rs
</code></pre>
<p>正确的解决方案如下:</p>
^{pr2}$
<p><a href="https://i.stack.imgur.com/Lt8PG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Lt8PG.png" alt="enter image description here"/></a></p>
<p>但是,拟合曲线的结果如下:</p>
^{3}$
<p><a href="https://i.stack.imgur.com/zdc3e.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zdc3e.png" alt="enter image description here"/></a></p>
<p>我的数据如下:</p>
<pre><code>r = np.array([100.09061214, 100.17932773, 100.45526772, 102.27891728,
113.12440802, 119.30644014, 119.86570527, 119.75184665,
117.12160143, 101.55081608, 100.07280857, 100.12880236,
100.39251753, 103.05404178, 117.15257288, 119.74048706,
119.86955437, 119.37452005, 112.83384329, 101.0507198 ,
100.05521567])
z = np.array([-407.90074345, -360.38004677, -312.99221012, -266.36934609,
-224.36240585, -188.55933945, -155.21242348, -122.02778866,
-87.84335638, -47.0274899 , 0. , 47.54559191,
94.97469981, 141.33801462, 181.59490575, 215.77219256,
248.95956379, 282.28027286, 318.16440024, 360.7246922 ,
407.940799 ])
</code></pre>
<p>因为我的函数只是表示一个傅立叶级数,所以我也尝试了scipy.fftpack.fft(r) 但是我无法重现一个接近我计算过的fft信号。在</p>