[英]Scipy ValueError: object too deep for desired array with optimize.leastsq
I am trying to fit my 3D data with linear 3D function Z = a x+b y+c. 我正在尝试使用线性3D函数Z = a x + b y + c来拟合我的3D数据。 I import the data with pandas: 我使用pandas导入数据:
dataframe = pd.read_csv('3d_data.csv',names=['x','y','z'],header=0)
print(dataframe)
x y z
0 52.830740 7.812507 0.000000
1 44.647931 61.031381 8.827942
2 38.725318 0.707952 52.857968
3 0.000000 31.026271 17.743218
4 57.137854 51.291656 61.546131
5 46.341341 3.394429 26.462564
6 3.440893 46.333864 70.440650
I have done some digging and found that the best way to fit 3D data it is to use optimize from scipy with the model equation and residual function: 我进行了一些挖掘,发现适合3D数据的最佳方法是使用带有模型方程式和残差函数的scipy优化:
def model_calc(parameter, x, y):
a, b, c = parameter
return a*x + b*y + c
def residual(parameter, data, x, y):
res = []
for _x in x:
for _y in y:
res.append(data-model_calc(parameter,x,y))
return res
I fit the data with: 我将数据拟合为:
params0 = [0.1, -0.2,1.]
result = scipy.optimize.leastsq(residual,params0,(dataframe['z'],dataframe['x'],dataframe['y']))
fittedParams = result[0]
But the result is a ValueError: 但是结果是ValueError:
ValueError: object too deep for desired array [...]
minpack.error: Result from function call is not a proper array of floats.
I was trying to minimize the residual function to give only single value or single np.array but it didn't help. 我试图最小化残差函数以仅给出单个值或单个np.array,但这没有帮助。 I don't know where is the problem and if maybe the search space for parameters it is not too complex. 我不知道问题出在哪里,如果参数的搜索空间不太复杂。 I would be very grateful for some hints! 我将非常感谢您提供一些提示!
If you are fitting parameters to a function, you can use curve_fit . 如果要为函数拟合参数,则可以使用curve_fit 。 Here's an implementation: 这是一个实现:
from scipy.optimize import curve_fit
def model_calc(X, a, b, c):
x, y = X
return a*x + b*y + c
p0 = [0.1, -0.2, 1.]
popt, pcov = curve_fit(model_calc, (dataframe.x, dataframe.y), dataframe.z, p0) #popt is the fit, pcov is the covariance matrix (see the docs)
Note that your sintax must be if the form f(X, a, b, c), where X can be a 2D vector (See this post ). 请注意,sintax必须为f(X,a,b,c)形式,其中X可以是2D向量(请参阅此文章 )。
(Another approach) (另一种方法)
If you know your fit is going to be linear, you can use numpy.linalg.lstsq
. 如果您知道拟合度将是线性的,则可以使用numpy.linalg.lstsq
。 See here . 看这里 。 Example solution: 解决方案示例:
import numpy as np
from numpy.linalg import lstsq
A = np.vstack((dataframe.x, dataframe.y, np.ones_like(dataframe.y))).T
B = dataframe.z
a, b, c = lstsq(A, B)[0]
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