Why it has syntax error?? In teta = th2[i]

Question

from math import cos, sin, pi
import numpy as np
from scipy.optimize import fsolve

r1 = 0.245
r2 = 0.35
r3 = 0.31292
r4 = 0.286356

th1 = 0
th2 = np.arange(0, pi/2, 0.1)
length = np.copy(th2)
for i in length:
teta = th2[i]

def posture(z):
th3 = z[0]
th4 = z[1]

p = np.zeros((2, 1))
p[0] = r1*cos(th1)+r2*cos(teta)+r3*cos(th3)+r4*cos(th4)
p[1] = r1*sin(th1)+r2*sin(teta)+r3*sin(th3)+r4*sin(th4)

return p
zGuess = np.array([3, 0.5])
z = fsolve(posture, zGuess)
print(z)

Answer 1

After a bit of research, I've found that numpy no longer allows floating point indexing. i is a float, which is why it gives the IndexError. As I don't really know what this code is doing, I can't offer any advice on how to fix. I have no idea why you get a Syntax Error.

Lothar 's point is that you create a new function definition for every loop. Much better and more efficient is to define the function once and take 'teta' as an argument.

Answer 2

There are several issues in the code. First of all you should unindent the complete function "posture" as it is to left side.
An other thing is this part of the code:

for i in length:
teta = th2[i]

Here you get values from array "length". in a for loop. As array contains only float numbers, you get an error message, because only integers are valid index values.

Answer 3

What should i do instead?

Answer 4

Sorry, I was wrong before. I ran the code and didn't get the error you described.

Here, it is giving an IndexError, but not when I run it on Pythonista 🤷‍♂️

https://code.sololearn.com/cQjznsS25UCJ/?ref=app

Answer 5

Thanks, do you know what can i do?

Answer 6

For this indexError

Answer 7

Alas no, sorry!

Answer 8

Thanks . But i didn't understand the "posture" issue?

Answer 9

👍 thanks.