Coding a summation formula

[rafl0913]

I need to make a summation formula currently under the name "num_approx"
I keep getting some errors I cant pinpoint how to fix.
This is my code:

 

import numpy as np
import math

T = 5777
h = 6.626e-34 #J/s
c = 2.998e17 #nm/s
k = 1.384e-23 #J/K
lambda_nm = 2500 #nm
C2nm= h*c/k
n = np.arange(1.0,11.0,1.0)
x = C2nm/(lambda_nm*T)

num_approx= 15/((math.pi)**4) * (exp(- n * x)/n)(x**3 + (3* x**2)/n + (6 * x^2)/(n**2) + (6)/(n**3))      


print("C2nm =", C2nm)
print("n =", n)
print("Numerical approximation is =", num_approx)

###########################

I get the following errors I cannot resolve. Please help.

Error:
TypeError                                 Traceback (most recent call last)
<ipython-input-13-0fa7a7e31d3e> in <module>
     10 n = np.arange(1.0,11.0,1.0)
     11 x = C2nm/(lambda_nm*T)
---> 12 num_approx= 15/((math.pi)**4) * (exp(- n * x)/n)(x**3 + (3* x**2)/n + (6 * x^2)/(n**2) + (6)/(n**3))
     13 
     14 

~\Anaconda3\lib\site-packages\mpmath\ctx_mp_python.py in f(x, **kwargs)
   1001         def f(x, **kwargs):
   1002             if type(x) not in ctx.types:
-> 1003                 x = ctx.convert(x)
   1004             prec, rounding = ctx._prec_rounding
   1005             if kwargs:

~\Anaconda3\lib\site-packages\mpmath\ctx_mp_python.py in convert(ctx, x, strings)
    646         if isinstance(x, complex):
    647             return ctx.make_mpc((from_float(x.real), from_float(x.imag)))
--> 648         if type(x).__module__ == 'numpy': return ctx.npconvert(x)
    649         if isinstance(x, numbers.Rational): # e.g. Fraction
    650             try: x = rational.mpq(int(x.numerator), int(x.denominator))

~\Anaconda3\lib\site-packages\mpmath\ctx_mp_python.py in npconvert(ctx, x)
    679         if isinstance(x, np.complexfloating):
    680             return ctx.make_mpc((from_npfloat(x.real), from_npfloat(x.imag)))
--> 681         raise TypeError("cannot create mpf from " + repr(x))
    682 
    683     def isnan(ctx, x):

TypeError: cannot create mpf from array([-0.99381282, -1.98762564, -2.98143845, -3.97525127, -4.96906409,
       -5.96287691, -6.95668972, -7.95050254, -8.94431536, -9.93812818])

[buran]

something is missing between (exp(- n * x)/n) and (x**3 + (3* x**2)/n + (6 * x^2)/(n**2) + (6)/(n**3))

[rafl0913]

Thanks for the catch, but I still get the same error.

import numpy as np
import math

T = 5777
h = 6.626e-34 #J/s
c = 2.998e17 #nm/s
k = 1.384e-23 #J/K
lambda_nm = 2500 #nm
C2nm= h*c/k
n = np.arange(1.0,11.0,1.0)
x = C2nm/(lambda_nm*T)
num_approx= 15/((math.pi)**4) * (exp(- n * x)/n) * (x**3 + (3* x**2)/n + (6 * x^2)/(n**2) + (6)/(n**3))      


print("C2nm =", C2nm)
print("n =", n)
print("Numerical approximation is =", num_approx)

---------------------------------------------------------------------------

Error:
TypeError                                 Traceback (most recent call last)
<ipython-input-15-4fc67e105602> in <module>
     10 n = np.arange(1.0,11.0,1.0)
     11 x = C2nm/(lambda_nm*T)
---> 12 num_approx= 15/((math.pi)**4) * (exp(- n * x)/n) * (x**3 + (3* x**2)/n + (6 * x^2)/(n**2) + (6)/(n**3))
     13 
     14 

~\Anaconda3\lib\site-packages\mpmath\ctx_mp_python.py in f(x, **kwargs)
   1001         def f(x, **kwargs):
   1002             if type(x) not in ctx.types:
-> 1003                 x = ctx.convert(x)
   1004             prec, rounding = ctx._prec_rounding
   1005             if kwargs:

~\Anaconda3\lib\site-packages\mpmath\ctx_mp_python.py in convert(ctx, x, strings)
    646         if isinstance(x, complex):
    647             return ctx.make_mpc((from_float(x.real), from_float(x.imag)))
--> 648         if type(x).__module__ == 'numpy': return ctx.npconvert(x)
    649         if isinstance(x, numbers.Rational): # e.g. Fraction
    650             try: x = rational.mpq(int(x.numerator), int(x.denominator))

~\Anaconda3\lib\site-packages\mpmath\ctx_mp_python.py in npconvert(ctx, x)
    679         if isinstance(x, np.complexfloating):
    680             return ctx.make_mpc((from_npfloat(x.real), from_npfloat(x.imag)))
--> 681         raise TypeError("cannot create mpf from " + repr(x))
    682 
    683     def isnan(ctx, x):

TypeError: cannot create mpf from array([-0.99381282, -1.98762564, -2.98143845, -3.97525127, -4.96906409,
       -5.96287691, -6.95668972, -7.95050254, -8.94431536, -9.93812818])

[ndc85430]

Did you really mean to write x^2 on line 12? Also, don't you need to qualify exp by its module name?