<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def invcdf(x):
 """Inverse of normal cumulative density function."""

    x_flat = np.ravel(x)
    x_trans = np.array([flib.ppnd16(y, 1) for y in x_flat])
    return np.reshape(x_trans, np.shape(x))