scipy python中变积分限的积分函数曲线拟合

3qpi33ja  于 2023-04-06  发布在  Python
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我想对积分函数应用curve_fit运算(以查找系数c1-c7
问题是次积分函数依赖于几个变量(列表defor,stress,init_def),积分极限也是可变的(列表init_def,defor)。
因此,积分函数是time=f(defor,stress)
积分应在参数(defor)上
我尝试了以下代码,但出现错误。如果您能帮助我,我将非常感激。提前非常感谢您。

import numpy as np
from scipy import integrate
from scipy.optimize import curve_fit
from scipy.integrate import quad

time =np.array([0, 18, 24, 42, 48, 66, 72, 0, 4, 22, 28, 46, 52, 70])
defor =np.array([0.11, 0.62, 0.73, 0.91, 1.0, 1.17, 1.22, 0.15, 0.26, 0.4, 0.43, 0.51, 0.51, 0.58])
init_def =np.array([0.11, 0.11, 0.11, 0.11, 0.11, 0.11, 0.11, 0.15, 0.15, 0.15, 0.15, 0.15, 0.15, 0.15])
stress =np.array([10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0,7.5, 7.5, 7.5, 7.5, 7.5, 7.5, 7.5])
temp=943
e=2.71828  
        
arg=zip(defor,stress,init_def)
    
# subint_funct- enter subintegral function with с1-с7 uncertain coefficients      
def subint_funct(arg, c1,c2, c3,c4,c5,c6,c7):
    return ((c1**(-1))*(temp**c2)*(stress**(-c3))*e**((c5-c6*stress)/temp)*
       ((defor+1)**(-c3))*(defor**c4)*e**(-((c6*stress+c7)*defor/temp))  ) 
    
# integration- integration of subint_funct with lower and upper integration bounds init_def and defor     
def integration(arg,c1,c2,c3,c4,c5,c6,c7):
    return [quad(subint_funct,init_def,defor,args= (c1,c2,c3,c4,c5,c6,c7) )[0] for defor,stress,init_def in arg ]

# curve fitting, dependent data-time
      
parameter = sp.curve_fit(integration,
                     arg,
                     time)
parameter=parameter[0]
print (parameter)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Input In [11], in <cell line: 25>()
     22 def integration(arg,c1,c2,c3,c4,c5,c6,c7):
     23     return [quad(subint_funct,init_def,defor,args= (c1,c2,c3,c4,c5,c6,c7) )[0] for defor,stress,init_def in arg ]
---> 25 parameter = sp.curve_fit(integration,
     26                          arg,
     27                          time)
     28 parameter=parameter[0]
     29 print (parameter)

File ~\anaconda3\lib\site-packages\scipy\optimize\minpack.py:789, in curve_fit(f, xdata, ydata, p0, sigma, absolute_sigma, check_finite, bounds, method, jac, **kwargs)
    787 # Remove full_output from kwargs, otherwise we're passing it in twice.
    788 return_full = kwargs.pop('full_output', False)
--> 789 res = leastsq(func, p0, Dfun=jac, full_output=1, **kwargs)
    790 popt, pcov, infodict, errmsg, ier = res
    791 ysize = len(infodict['fvec'])

File ~\anaconda3\lib\site-packages\scipy\optimize\minpack.py:410, in leastsq(func, x0, args, Dfun, full_output, col_deriv, ftol, xtol, gtol, maxfev, epsfcn, factor, diag)
    408 if not isinstance(args, tuple):
    409     args = (args,)
--> 410 shape, dtype = _check_func('leastsq', 'func', func, x0, args, n)
    411 m = shape[0]
    413 if n > m:

File ~\anaconda3\lib\site-packages\scipy\optimize\minpack.py:24, in _check_func(checker, argname, thefunc, x0, args, numinputs, output_shape)
     22 def _check_func(checker, argname, thefunc, x0, args, numinputs,
     23                 output_shape=None):
---> 24     res = atleast_1d(thefunc(*((x0[:numinputs],) + args)))
     25     if (output_shape is not None) and (shape(res) != output_shape):
     26         if (output_shape[0] != 1):

File ~\anaconda3\lib\site-packages\scipy\optimize\minpack.py:485, in _wrap_func.<locals>.func_wrapped(params)
    484 def func_wrapped(params):
--> 485     return func(xdata, *params) - ydata

Input In [11], in integration(arg, c1, c2, c3, c4, c5, c6, c7)
     22 def integration(arg,c1,c2,c3,c4,c5,c6,c7):
---> 23     return [quad(subint_funct,init_def,defor,args= (c1,c2,c3,c4,c5,c6,c7) )[0] for defor,stress,init_def in arg ]

Input In [11], in <listcomp>(.0)
     22 def integration(arg,c1,c2,c3,c4,c5,c6,c7):
---> 23     return [quad(subint_funct,init_def,defor,args= (c1,c2,c3,c4,c5,c6,c7) )[0] for defor,stress,init_def in arg ]

File ~\anaconda3\lib\site-packages\scipy\integrate\quadpack.py:351, in quad(func, a, b, args, full_output, epsabs, epsrel, limit, points, weight, wvar, wopts, maxp1, limlst)
    348 flip, a, b = b < a, min(a, b), max(a, b)
    350 if weight is None:
--> 351     retval = _quad(func, a, b, args, full_output, epsabs, epsrel, limit,
    352                    points)
    353 else:
    354     if points is not None:

File ~\anaconda3\lib\site-packages\scipy\integrate\quadpack.py:463, in _quad(func, a, b, args, full_output, epsabs, epsrel, limit, points)
    461 if points is None:
    462     if infbounds == 0:
--> 463         return _quadpack._qagse(func,a,b,args,full_output,epsabs,epsrel,limit)
    464     else:
    465         return _quadpack._qagie(func,bound,infbounds,args,full_output,epsabs,epsrel,limit)

TypeError: only size-1 arrays can be converted to Python scalars
p5fdfcr1

p5fdfcr11#

由于我不是100%确定OP的细节,这里有一个例子做类似的事情。简单的修改应该可以做到这一点。

import numpy as np
from scipy.integrate import quad
from scipy.optimize import curve_fit

### not clever, but whatever...
def integ( arg, c1, c2, c3 ):
    x, k1 = arg
    return k1**c1 * x**c2 + c3

def integ_first_wrapper( x, k, c):
    return(integ( ( x, k ), *c ) )

def fitwrapper( xlist, c1, c2, c3 ):
    if len( xlist.shape ) == 2: ##array
        out = np.fromiter(
            ( fitwrapper( x, c1, c2, c3 ) for x in xlist ),
            np.float
        )
    else:
        l, u, s = xlist
        out = quad(
            integ_first_wrapper, l, u, args=( s, ( c1, c2, c3 ) )
        )[0]
    return out

c10 = 2.33
c20 = 3.11
c30 = 4.11

lolimits = 5 * np.random.random( size=10 )
uplimits = 10 + 5 * np.random.random( size=10 )
stress = 28 * np.random.random( size=10 )

xin = np.transpose( ( lolimits, uplimits, stress ) )

### create test data
data = list()
for l,u, s in zip( lolimits, uplimits, stress ):
    # ~data.append( quad( integ_first_wrapper, l, u, args=( s, (c10, c20, c30 ) ) )[0] ) ### without error
    data.append(
        ( 1 + 0.01 * ( 1 - 2 * np.random.random() ) )
         * quad(
            integ_first_wrapper, l, u, args=( s, (c10, c20, c30 ) )
        )[0]
    ) ### wit relative error

# ~print(xin)
res, err = curve_fit( fitwrapper, xin, data, p0=( 1, 1, 1 ) )
print( res )
print( err )

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