def colormesh(X, Y):
    """
    Generates line paths for a quadmesh given 2D arrays of X and Y
    coordinates.
    """
    X1 = X[0:-1, 0:-1].ravel()
    Y1 = Y[0:-1, 0:-1].ravel()
    X2 = X[1:, 0:-1].ravel()
    Y2 = Y[1:, 0:-1].ravel()
    X3 = X[1:, 1:].ravel()
    Y3 = Y[1:, 1:].ravel()
    X4 = X[0:-1, 1:].ravel()
    Y4 = Y[0:-1, 1:].ravel()

    X = np.column_stack([X1, X2, X3, X4, X1])
    Y = np.column_stack([Y1, Y2, Y3, Y4, Y1])
    return X, Y
Generates line paths for a quadmesh given 2D arrays of X and Y
    coordinates.