Python Forum

Can anyone make a look to following code why it cant calculate complex numbers in the defined arrray.

import numpy as np

n=5
alpha = 0.7
A=np.zeros([n+1,n+1])
B=np.zeros([n+1])
#sum=0
for i in range(n+1):
    for j in range(n+1):
        A[i][j]=(i-j)**(alpha)
            
        
print(A) 

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

Error:
TypeError                                 Traceback (most recent call last)
<ipython-input-20-265607fc02b7> in <module>
      8 for i in range(n+1):
      9     for j in range(n+1):
---> 10         A[i][j]=(i-j)**(alpha)
     11 
     12 

TypeError: can't convert complex to float

Please use Code-Tags for code, otherwise the indentation is lost.


You have to chose the right data type. Use numpy.complex128 as dtype.
The real part is a 64 bit float and the imaginary part is a 64 bit float.
In addition you can use product from itertools, to get rid of the nested loop.
You can also access more than one axis in a multidimensional array.
Last thing is: You can reuse the range object.

import numpy as np
from itertools import product

n = 5
alpha = 0.7
A = np.zeros([n+1,n+1], dtype=np.complex128)
B = np.zeros([n+1], dtype=np.complex128)


r = range(n+1)
for i,j in product(r, r):
    A[i,j] = (i-j) ** alpha


print(A)

(Nov-04-2019, 04:18 PM)DeaD_EyE Wrote: [ -> ]Please use Code-Tags for code, otherwise the indentation is lost. You have to chose the right data type. Use numpy.complex128 as dtype. The real part is a 64 bit float and the imaginary part is a 64 bit float. In addition you can use product from itertools, to get rid of the nested loop. You can also access more than one axis in a multidimensional array. Last thing is: You can reuse the range object.

 import numpy as np from itertools import product n = 5 alpha = 0.7 A = np.zeros([n+1,n+1], dtype=np.complex128) B = np.zeros([n+1], dtype=np.complex128) r = range(n+1) for i,j in product(r, r): A[i,j] = (i-j) ** alpha print(A) 

Thanks for the suggestion
Why you choose n+1 instead of n=5 in array ?