I have a matrix with shape (x,y,z) and in each matrix element I store a 3D array with the components of the magnetic field in that point. But when I try to plot the points at y=0 the quiver representation is weird.
For example bx at z=7 (in the middle): print(bx[:,7]) gives this output [0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.]

But the quiver plot at z=0 gives non zero x values as you can see

The code:

import numpy as np
from scipy import constants as cst
import matplotlib.pyplot as plt

#UDS SI
prefactor = cst.mu_0/4/np.pi
N=10#discretizacion de espira 
I=-1#corriente 
R=0.5#rad esp

def biotsav(i,dl,r):
    return prefactor*i*np.cross(dl,r)/np.linalg.norm(r)**3

#espira en x,y discretizada
#por defecto en centro
def createSpiral(r,n_intervals,center = [0,0,0]):
    theta = np.linspace(0,2*np.pi,n_intervals)
    return np.array([center[0]+r*np.cos(theta),
                     center[1]+r*np.sin(theta),center[2]+np.zeros(n_intervals)]).T

def calculateDirVect(dl,dlant):
    u=[]
    for i in range(3):
        u.append(dl[i]-dlant[i])
    return u

def calculateRefPoint(dl,dlant):
    ref = []
    for i in range(3):
        ref.append((dl[i]+dlant[i])/2)
    return ref
def calculateDispVect(dl,p):
    r=[]
    for i in range((3)):
        r.append(p[i]-dl[i])
    return r
    

spiral= createSpiral(R,N,center=[1.5,1.5,1.5])
#Fijamos el punto z para el plano xy
totalB=0
zs=np.linspace(0,3,15)
xs=np.linspace(0,3,15)
ys=np.linspace(0,3,15)
b = np.empty((len(xs),len(ys),len(zs)),dtype=object)
for i in range(len(xs)):
    for j in range(len(ys)):
        for k in range(len(zs)):
            totalB=np.array([0.,0.,0.])
            dlant = spiral[-1]
            p=[xs[i],ys[j],zs[k]]
            for dl in spiral:
                u = calculateDirVect(dl,dlant)
                ref = calculateRefPoint(dl,dlant)
                r = calculateDispVect(dl,p)  
                dlant=dl
                totalB+=(biotsav(I,u,r))
            b[i,j,k] = totalB

bx=np.zeros((len(xs),len(zs)),dtype='float')
bz=np.zeros((len(xs),len(zs)),dtype='float')
for i in range(len(xs)):
    for k in range(len(zs)):
        bx[i,k]=(b[i,0,k][0])
        bz[i,k]=(b[i,0,k][2])

# Trazar los vectores del campo magnético con quiver
X, Z = np.meshgrid(xs, zs)
print(bx[:,7])
plt.quiver(X, Z, bx, bz)
plt.xlabel('x')
plt.ylabel('z')
plt.title('Campo Magnético')
plt.show()

Where am I wrong, as far as I know the 3rd and 4th attribute in quiver are the x and y direction of the arrows