qiskit/visualization/state_visualization.py
def plot_bloch_multivector(rho, title='', figsize=None):
    """Plot the Bloch sphere.

    Plot a sphere, axes, the Bloch vector, and its projections onto each axis.

    Args:
        rho (ndarray): Numpy array for state vector or density matrix.
        title (str): a string that represents the plot title
        figsize (tuple): Has no effect, here for compatibility only.

    Returns:
        Figure: A matplotlib figure instance if `ax = None`.

    Raises:
        ImportError: Requires matplotlib.
    """
    if not HAS_MATPLOTLIB:
        raise ImportError('Must have Matplotlib installed.')
    rho = _validate_input_state(rho)
    num = int(np.log2(len(rho)))
    width, height = plt.figaspect(1/num)
    fig = plt.figure(figsize=(width, height))
    for i in range(num):
        ax = fig.add_subplot(1, num, i + 1, projection='3d')
        pauli_singles = [
            Pauli.pauli_single(num, i, 'X'),
            Pauli.pauli_single(num, i, 'Y'),
            Pauli.pauli_single(num, i, 'Z')
        ]
        bloch_state = list(
            map(lambda x: np.real(np.trace(np.dot(x.to_matrix(), rho))),
                pauli_singles))
        plot_bloch_vector(bloch_state, "qubit " + str(i), ax=ax,
                          figsize=figsize)
    fig.suptitle(title, fontsize=16)
    plt.close(fig)
    return fig
def plot_bloch_multivector(rho, title='', figsize=None):
    """Plot the Bloch sphere.

    Plot a sphere, axes, the Bloch vector, and its projections onto each axis.

    Args:
        rho (ndarray): Numpy array for state vector or density matrix.
        title (str): a string that represents the plot title
        figsize (tuple): Has no effect, here for compatibility only.

    Returns:
        Figure: A matplotlib figure instance if `ax = None`.

    Raises:
        ImportError: Requires matplotlib.
    """
    if not HAS_MATPLOTLIB:
        raise ImportError('Must have Matplotlib installed.')
    rho = _validate_input_state(rho)
    num = int(np.log2(len(rho)))
    width, height = plt.figaspect(1/num)
    fig = plt.figure(figsize=(width, height))
    for i in range(num):
        ax = fig.add_subplot(1, num, i + 1, projection='3d')
        pauli_singles = [
            Pauli.pauli_single(num, i, 'X'),
            Pauli.pauli_single(num, i, 'Y'),
            Pauli.pauli_single(num, i, 'Z')
        ]
        bloch_state = list(
            map(lambda x: np.real(np.trace(np.dot(x.to_matrix(), rho))),
                pauli_singles))
        plot_bloch_vector(bloch_state, "qubit " + str(i), ax=ax,
                          figsize=figsize)
    fig.suptitle(title, fontsize=16)
    plt.close(fig)
    return fig
def plot_bloch_multivector ( rho , title = '' , figsize = None ) : if not HAS_MATPLOTLIB : raise ImportError ( 'Must have Matplotlib installed.' ) rho = _validate_input_state ( rho ) num = int ( np . log2 ( len ( rho ) ) ) width , height = plt . figaspect ( 1 / num ) fig = plt . figure ( figsize = ( width , height ) ) for i in range ( num ) : ax = fig . add_subplot ( 1 , num , i + 1 , projection = '3d' ) pauli_singles = [ Pauli . pauli_single ( num , i , 'X' ) , Pauli . pauli_single ( num , i , 'Y' ) , Pauli . pauli_single ( num , i , 'Z' ) ] bloch_state = list ( map ( lambda x : np . real ( np . trace ( np . dot ( x . to_matrix ( ) , rho ) ) ) , pauli_singles ) ) plot_bloch_vector ( bloch_state , "qubit " + str ( i ) , ax = ax , figsize = figsize ) fig . suptitle ( title , fontsize = 16 ) plt . close ( fig ) return fig
Plot the Bloch sphere.

    Plot a sphere, axes, the Bloch vector, and its projections onto each axis.

    Args:
        rho (ndarray): Numpy array for state vector or density matrix.
        title (str): a string that represents the plot title
        figsize (tuple): Has no effect, here for compatibility only.

    Returns:
        Figure: A matplotlib figure instance if `ax = None`.

    Raises:
        ImportError: Requires matplotlib.
Plot the Bloch sphere .