Fix Sympy Not Working: TypeError

[ergospherical]

Computer says "TypeError: Data type not understood; expecting list of lists or lists of values."

import sympy as sp

t,r,a,b = sp.symbols('t r a b')

g00 = -(1-(1/r))
g01 = 0
g02 = 0
g03 = 0
g10 = 0
g11 = 1/(1-(1/r))
g12 = 0
g13 = 0
g20 = 0
g21 = 0
g22 = r**2
g23 = 0
g30 = 0
g31 = 0
g32 = 0
g33 = (r**2)*((sp.sin(a))**2)

g = sp.Matrix([g00,g01,g02,g03],[g10,g11,g12,g13],[g20,g21,g22,g23],[g30,g31,g32,g33])
print(g)

 

[jedishrfu]

Make a list as a variable named “glist”

and then use it as the argument to Matrix

find an example online using sp.Matrix as a reference.

 

[phyzguy]

You just need to make the Matrix input a nested list, like this:

g = sp.Matrix([[g00,g01,g02,g03],[g10,g11,g12,g13],[g20,g21,g22,g23],[g30,g31,g32,g33]])

This is what the error message means when it says a "list of lists".

 

[jedishrfu]

Aah the old list of lists trick -- Maxwell Smart of Get Smart!

 

[pbuk]

Matrices as lists of lists are horrible, numpy.ndarray is much nicer.