Val Error, x and y must have the same dimension. [I tried to do np.array but it hasn't helped]

Question

x and y must have same first dimension, but have shapes (1, 400) and (400,)

I have search this forum and saw that people suggested to do np.array to solve this, but it didn't seem to work.

def function(a, v):
speedx = 0.0
yt = -1.0
val = []
for i in len(a):
    xt = a[0]
    vx = -2.0 * yt**2 * xt * (1 - xt**3) 
    vy = -2.0 * xt**2 * yt * (1 - yt**3)
    angle = np.atan2(vy,vx)
    val.append(angle)
return np.array([val])


rge = np.arange(-0.2, 0.2, 0.001)
a = np.array(rg)
speedy = 0.1 #vy

ans = odeint(function, a, speedy)

plt.plot(ans, a)

Answer 1

When you return np.array([val]) , that makes a two dimensional array because val is already an array. That is why the shape is (1,400) which makes it two dimensional with the size of the first dimension being 1. You can try:

return np.array(val)

That may help. Also, the code you have pasted has obvious bugs which I am assuming are typos like angle.append should have been val.append .