在下面的代码中，我得到了错误

n = 101                # Number of grid points
P = np.zeros((n, n))
xmin, xmax = 0.0, 1.0     # limits in the x direction
ymin, ymax = -0.5, 0.5

x = np.linspace(xmin, xmax, nx)
y = np.linspace(ymin, ymax, ny)
X, Y = np.meshgrid(x, y, indexing='ij')
a = ((D/(dx*dx))-(X-Y*Y)/(2*dx))
b = (2+X-4*D/(dx*dx))
c = ((D/(dx*dx))-(Y+X*Y)/(2*dx))
d = ((D/(dx*dx))+(Y+X*Y)/(2*dx))
e = ((D/(dx*dx))+(X-Y*Y)/(2*dx))

### boundary conditions
for i in range(len(P)):

     P[i, 0] = 0               # Left boundary
     P[i, -1] = 0                     # Right boundary
     P[0, i] = 0         # Lower boudary
     P[-1, i] = 0                    
f = 0.
w = 1.2

resid_crit = 1.0e-6

# Arbitrary value at the begining, higher than resid_crit
resid_ave = 100.

count = 0

while resid_ave > resid_crit:

    # Set at 0 so we can sum it up later
    resid_ave = 0.

    # Set count for points in checker-boarding
    cnt_points = 0

    # Loop over internal points only
    for i in range(1, n - 1):
        for j in range(1, n - 1):

            # Checker-boarding
            if ((i + j) % 2) == count % 2:
                # Residual
                residual = a[i,j] * P[i - 1, j] + b[i,j] * P[i, j] + c[i,j] * P[i, j - 1] + d[i,j] * P[i, j + 1] + e * P[
                    i+1, j] - f

                # Update psi value

                P[i, j] += -w * residual / b[i,j]

                # Update resid_ave as a sum of residuals
                resid_ave += abs(residual)

                cnt_points += 1

    #  Get average residual
    resid_ave = resid_ave / cnt_points

    # Print every 1000-dth residual
    if count % 1000 == 0:
        print("Residual: %.7f" % resid_ave)
        #print("Residual: ", resid_ave)

    # Count iterations
    count = count + 1

输出显示：

TypeError: only size-1 arrays can be converted to Python scalars

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\gitsa\PycharmProjects\sagarPy1\SKtest.py", line 89, in <module>
    P[i, j] += -w * residual / b[i,j]
ValueError: setting an array element with a sequence.