qiskit/visualization/circuit_visualization.py
def circuit_drawer(circuit,
                   scale=0.7,
                   filename=None,
                   style=None,
                   output='text',
                   interactive=False,
                   line_length=None,
                   plot_barriers=True,
                   reverse_bits=False,
                   justify=None):
    """Draw a quantum circuit to different formats (set by output parameter):
    0. text: ASCII art TextDrawing that can be printed in the console.
    1. latex: high-quality images, but heavy external software dependencies
    2. matplotlib: purely in Python with no external dependencies

    Args:
        circuit (QuantumCircuit): the quantum circuit to draw
        scale (float): scale of image to draw (shrink if < 1)
        filename (str): file path to save image to
        style (dict or str): dictionary of style or file name of style file.
            This option is only used by the `mpl`, `latex`, and `latex_source`
            output types. If a str is passed in that is the path to a json
            file which contains that will be open, parsed, and then used just
            as the input dict.
        output (TextDrawing): Select the output method to use for drawing the circuit.
            Valid choices are `text`, `latex`, `latex_source`, `mpl`. Note if
            one is not specified it will use latex and if that fails fallback
            to mpl. However this behavior is deprecated and in a future release
            the default will change.
        interactive (bool): when set true show the circuit in a new window
            (for `mpl` this depends on the matplotlib backend being used
            supporting this). Note when used with either the `text` or the
            `latex_source` output type this has no effect and will be silently
            ignored.
        line_length (int): Sets the length of the lines generated by `text`
            output type. This useful when the drawing does not fit in the
            console. If None (default), it will try to guess the console width
            using shutil.get_terminal_size(). However, if you're running in
            jupyter the default line length is set to 80 characters. If you
            don't want pagination at all, set `line_length=-1`.
        reverse_bits (bool): When set to True reverse the bit order inside
            registers for the output visualization.
        plot_barriers (bool): Enable/disable drawing barriers in the output
            circuit. Defaults to True.
        justify (string): Options are `left`, `right` or `none`, if anything
            else is supplied it defaults to left justified. It refers to where
            gates should be placed in the output circuit if there is an option.
            `none` results in each gate being placed in its own column. Currently
            only supported by text drawer.

    Returns:
        PIL.Image: (output `latex`) an in-memory representation of the image
            of the circuit diagram.
        matplotlib.figure: (output `mpl`) a matplotlib figure object for the
            circuit diagram.
        String: (output `latex_source`). The LaTeX source code.
        TextDrawing: (output `text`). A drawing that can be printed as ascii art
    Raises:
        VisualizationError: when an invalid output method is selected
        ImportError: when the output methods requieres non-installed libraries.

    .. _style-dict-doc:

    The style dict kwarg contains numerous options that define the style of the
    output circuit visualization. While the style dict is used by the `mpl`,
    `latex`, and `latex_source` outputs some options in that are only used
    by the `mpl` output. These options are defined below, if it is only used by
    the `mpl` output it is marked as such:

        textcolor (str): The color code to use for text. Defaults to
            `'#000000'` (`mpl` only)
        subtextcolor (str): The color code to use for subtext. Defaults to
            `'#000000'` (`mpl` only)
        linecolor (str): The color code to use for lines. Defaults to
            `'#000000'` (`mpl` only)
        creglinecolor (str): The color code to use for classical register lines
            `'#778899'`(`mpl` only)
        gatetextcolor (str): The color code to use for gate text `'#000000'`
            (`mpl` only)
        gatefacecolor (str): The color code to use for gates. Defaults to
            `'#ffffff'` (`mpl` only)
        barrierfacecolor (str): The color code to use for barriers. Defaults to
            `'#bdbdbd'` (`mpl` only)
        backgroundcolor (str): The color code to use for the background.
            Defaults to `'#ffffff'` (`mpl` only)
        fontsize (int): The font size to use for text. Defaults to 13 (`mpl`
            only)
        subfontsize (int): The font size to use for subtext. Defaults to 8
            (`mpl` only)
        displaytext (dict): A dictionary of the text to use for each element
            type in the output visualization. The default values are:
            {
                'id': 'id',
                'u0': 'U_0',
                'u1': 'U_1',
                'u2': 'U_2',
                'u3': 'U_3',
                'x': 'X',
                'y': 'Y',
                'z': 'Z',
                'h': 'H',
                's': 'S',
                'sdg': 'S^\\dagger',
                't': 'T',
                'tdg': 'T^\\dagger',
                'rx': 'R_x',
                'ry': 'R_y',
                'rz': 'R_z',
                'reset': '\\left|0\\right\\rangle'
            }
            You must specify all the necessary values if using this. There is
            no provision for passing an incomplete dict in. (`mpl` only)
        displaycolor (dict): The color codes to use for each circuit element.
            By default all values default to the value of `gatefacecolor` and
            the keys are the same as `displaytext`. Also, just like
            `displaytext` there is no provision for an incomplete dict passed
            in. (`mpl` only)
        latexdrawerstyle (bool): When set to True enable latex mode which will
            draw gates like the `latex` output modes. (`mpl` only)
        usepiformat (bool): When set to True use radians for output (`mpl`
            only)
        fold (int): The number of circuit elements to fold the circuit at.
            Defaults to 20 (`mpl` only)
        cregbundle (bool): If set True bundle classical registers (`mpl` only)
        showindex (bool): If set True draw an index. (`mpl` only)
        compress (bool): If set True draw a compressed circuit (`mpl` only)
        figwidth (int): The maximum width (in inches) for the output figure.
            (`mpl` only)
        dpi (int): The DPI to use for the output image. Defaults to 150 (`mpl`
            only)
        margin (list): `mpl` only
        creglinestyle (str): The style of line to use for classical registers.
            Choices are `'solid'`, `'doublet'`, or any valid matplotlib
            `linestyle` kwarg value. Defaults to `doublet`(`mpl` only)
    """
    image = None

    if output == 'text':
        return _text_circuit_drawer(circuit, filename=filename,
                                    line_length=line_length,
                                    reverse_bits=reverse_bits,
                                    plotbarriers=plot_barriers,
                                    justify=justify)
    elif output == 'latex':
        image = _latex_circuit_drawer(circuit, scale=scale,
                                      filename=filename, style=style,
                                      plot_barriers=plot_barriers,
                                      reverse_bits=reverse_bits,
                                      justify=justify)
    elif output == 'latex_source':
        return _generate_latex_source(circuit,
                                      filename=filename, scale=scale,
                                      style=style,
                                      plot_barriers=plot_barriers,
                                      reverse_bits=reverse_bits,
                                      justify=justify)
    elif output == 'mpl':
        image = _matplotlib_circuit_drawer(circuit, scale=scale,
                                           filename=filename, style=style,
                                           plot_barriers=plot_barriers,
                                           reverse_bits=reverse_bits,
                                           justify=justify)
    else:
        raise exceptions.VisualizationError(
            'Invalid output type %s selected. The only valid choices '
            'are latex, latex_source, text, and mpl' % output)
    if image and interactive:
        image.show()
    return image
def circuit_drawer(circuit,
                   scale=0.7,
                   filename=None,
                   style=None,
                   output='text',
                   interactive=False,
                   line_length=None,
                   plot_barriers=True,
                   reverse_bits=False,
                   justify=None):
    """Draw a quantum circuit to different formats (set by output parameter):
    0. text: ASCII art TextDrawing that can be printed in the console.
    1. latex: high-quality images, but heavy external software dependencies
    2. matplotlib: purely in Python with no external dependencies

    Args:
        circuit (QuantumCircuit): the quantum circuit to draw
        scale (float): scale of image to draw (shrink if < 1)
        filename (str): file path to save image to
        style (dict or str): dictionary of style or file name of style file.
            This option is only used by the `mpl`, `latex`, and `latex_source`
            output types. If a str is passed in that is the path to a json
            file which contains that will be open, parsed, and then used just
            as the input dict.
        output (TextDrawing): Select the output method to use for drawing the circuit.
            Valid choices are `text`, `latex`, `latex_source`, `mpl`. Note if
            one is not specified it will use latex and if that fails fallback
            to mpl. However this behavior is deprecated and in a future release
            the default will change.
        interactive (bool): when set true show the circuit in a new window
            (for `mpl` this depends on the matplotlib backend being used
            supporting this). Note when used with either the `text` or the
            `latex_source` output type this has no effect and will be silently
            ignored.
        line_length (int): Sets the length of the lines generated by `text`
            output type. This useful when the drawing does not fit in the
            console. If None (default), it will try to guess the console width
            using shutil.get_terminal_size(). However, if you're running in
            jupyter the default line length is set to 80 characters. If you
            don't want pagination at all, set `line_length=-1`.
        reverse_bits (bool): When set to True reverse the bit order inside
            registers for the output visualization.
        plot_barriers (bool): Enable/disable drawing barriers in the output
            circuit. Defaults to True.
        justify (string): Options are `left`, `right` or `none`, if anything
            else is supplied it defaults to left justified. It refers to where
            gates should be placed in the output circuit if there is an option.
            `none` results in each gate being placed in its own column. Currently
            only supported by text drawer.

    Returns:
        PIL.Image: (output `latex`) an in-memory representation of the image
            of the circuit diagram.
        matplotlib.figure: (output `mpl`) a matplotlib figure object for the
            circuit diagram.
        String: (output `latex_source`). The LaTeX source code.
        TextDrawing: (output `text`). A drawing that can be printed as ascii art
    Raises:
        VisualizationError: when an invalid output method is selected
        ImportError: when the output methods requieres non-installed libraries.

    .. _style-dict-doc:

    The style dict kwarg contains numerous options that define the style of the
    output circuit visualization. While the style dict is used by the `mpl`,
    `latex`, and `latex_source` outputs some options in that are only used
    by the `mpl` output. These options are defined below, if it is only used by
    the `mpl` output it is marked as such:

        textcolor (str): The color code to use for text. Defaults to
            `'#000000'` (`mpl` only)
        subtextcolor (str): The color code to use for subtext. Defaults to
            `'#000000'` (`mpl` only)
        linecolor (str): The color code to use for lines. Defaults to
            `'#000000'` (`mpl` only)
        creglinecolor (str): The color code to use for classical register lines
            `'#778899'`(`mpl` only)
        gatetextcolor (str): The color code to use for gate text `'#000000'`
            (`mpl` only)
        gatefacecolor (str): The color code to use for gates. Defaults to
            `'#ffffff'` (`mpl` only)
        barrierfacecolor (str): The color code to use for barriers. Defaults to
            `'#bdbdbd'` (`mpl` only)
        backgroundcolor (str): The color code to use for the background.
            Defaults to `'#ffffff'` (`mpl` only)
        fontsize (int): The font size to use for text. Defaults to 13 (`mpl`
            only)
        subfontsize (int): The font size to use for subtext. Defaults to 8
            (`mpl` only)
        displaytext (dict): A dictionary of the text to use for each element
            type in the output visualization. The default values are:
            {
                'id': 'id',
                'u0': 'U_0',
                'u1': 'U_1',
                'u2': 'U_2',
                'u3': 'U_3',
                'x': 'X',
                'y': 'Y',
                'z': 'Z',
                'h': 'H',
                's': 'S',
                'sdg': 'S^\\dagger',
                't': 'T',
                'tdg': 'T^\\dagger',
                'rx': 'R_x',
                'ry': 'R_y',
                'rz': 'R_z',
                'reset': '\\left|0\\right\\rangle'
            }
            You must specify all the necessary values if using this. There is
            no provision for passing an incomplete dict in. (`mpl` only)
        displaycolor (dict): The color codes to use for each circuit element.
            By default all values default to the value of `gatefacecolor` and
            the keys are the same as `displaytext`. Also, just like
            `displaytext` there is no provision for an incomplete dict passed
            in. (`mpl` only)
        latexdrawerstyle (bool): When set to True enable latex mode which will
            draw gates like the `latex` output modes. (`mpl` only)
        usepiformat (bool): When set to True use radians for output (`mpl`
            only)
        fold (int): The number of circuit elements to fold the circuit at.
            Defaults to 20 (`mpl` only)
        cregbundle (bool): If set True bundle classical registers (`mpl` only)
        showindex (bool): If set True draw an index. (`mpl` only)
        compress (bool): If set True draw a compressed circuit (`mpl` only)
        figwidth (int): The maximum width (in inches) for the output figure.
            (`mpl` only)
        dpi (int): The DPI to use for the output image. Defaults to 150 (`mpl`
            only)
        margin (list): `mpl` only
        creglinestyle (str): The style of line to use for classical registers.
            Choices are `'solid'`, `'doublet'`, or any valid matplotlib
            `linestyle` kwarg value. Defaults to `doublet`(`mpl` only)
    """
    image = None

    if output == 'text':
        return _text_circuit_drawer(circuit, filename=filename,
                                    line_length=line_length,
                                    reverse_bits=reverse_bits,
                                    plotbarriers=plot_barriers,
                                    justify=justify)
    elif output == 'latex':
        image = _latex_circuit_drawer(circuit, scale=scale,
                                      filename=filename, style=style,
                                      plot_barriers=plot_barriers,
                                      reverse_bits=reverse_bits,
                                      justify=justify)
    elif output == 'latex_source':
        return _generate_latex_source(circuit,
                                      filename=filename, scale=scale,
                                      style=style,
                                      plot_barriers=plot_barriers,
                                      reverse_bits=reverse_bits,
                                      justify=justify)
    elif output == 'mpl':
        image = _matplotlib_circuit_drawer(circuit, scale=scale,
                                           filename=filename, style=style,
                                           plot_barriers=plot_barriers,
                                           reverse_bits=reverse_bits,
                                           justify=justify)
    else:
        raise exceptions.VisualizationError(
            'Invalid output type %s selected. The only valid choices '
            'are latex, latex_source, text, and mpl' % output)
    if image and interactive:
        image.show()
    return image
Draw a quantum circuit to different formats (set by output parameter):
    0. text: ASCII art TextDrawing that can be printed in the console.
    1. latex: high-quality images, but heavy external software dependencies
    2. matplotlib: purely in Python with no external dependencies

    Args:
        circuit (QuantumCircuit): the quantum circuit to draw
        scale (float): scale of image to draw (shrink if < 1)
        filename (str): file path to save image to
        style (dict or str): dictionary of style or file name of style file.
            This option is only used by the `mpl`, `latex`, and `latex_source`
            output types. If a str is passed in that is the path to a json
            file which contains that will be open, parsed, and then used just
            as the input dict.
        output (TextDrawing): Select the output method to use for drawing the circuit.
            Valid choices are `text`, `latex`, `latex_source`, `mpl`. Note if
            one is not specified it will use latex and if that fails fallback
            to mpl. However this behavior is deprecated and in a future release
            the default will change.
        interactive (bool): when set true show the circuit in a new window
            (for `mpl` this depends on the matplotlib backend being used
            supporting this). Note when used with either the `text` or the
            `latex_source` output type this has no effect and will be silently
            ignored.
        line_length (int): Sets the length of the lines generated by `text`
            output type. This useful when the drawing does not fit in the
            console. If None (default), it will try to guess the console width
            using shutil.get_terminal_size(). However, if you're running in
            jupyter the default line length is set to 80 characters. If you
            don't want pagination at all, set `line_length=-1`.
        reverse_bits (bool): When set to True reverse the bit order inside
            registers for the output visualization.
        plot_barriers (bool): Enable/disable drawing barriers in the output
            circuit. Defaults to True.
        justify (string): Options are `left`, `right` or `none`, if anything
            else is supplied it defaults to left justified. It refers to where
            gates should be placed in the output circuit if there is an option.
            `none` results in each gate being placed in its own column. Currently
            only supported by text drawer.

    Returns:
        PIL.Image: (output `latex`) an in-memory representation of the image
            of the circuit diagram.
        matplotlib.figure: (output `mpl`) a matplotlib figure object for the
            circuit diagram.
        String: (output `latex_source`). The LaTeX source code.
        TextDrawing: (output `text`). A drawing that can be printed as ascii art
    Raises:
        VisualizationError: when an invalid output method is selected
        ImportError: when the output methods requieres non-installed libraries.

    .. _style-dict-doc:

    The style dict kwarg contains numerous options that define the style of the
    output circuit visualization. While the style dict is used by the `mpl`,
    `latex`, and `latex_source` outputs some options in that are only used
    by the `mpl` output. These options are defined below, if it is only used by
    the `mpl` output it is marked as such:

        textcolor (str): The color code to use for text. Defaults to
            `'#000000'` (`mpl` only)
        subtextcolor (str): The color code to use for subtext. Defaults to
            `'#000000'` (`mpl` only)
        linecolor (str): The color code to use for lines. Defaults to
            `'#000000'` (`mpl` only)
        creglinecolor (str): The color code to use for classical register lines
            `'#778899'`(`mpl` only)
        gatetextcolor (str): The color code to use for gate text `'#000000'`
            (`mpl` only)
        gatefacecolor (str): The color code to use for gates. Defaults to
            `'#ffffff'` (`mpl` only)
        barrierfacecolor (str): The color code to use for barriers. Defaults to
            `'#bdbdbd'` (`mpl` only)
        backgroundcolor (str): The color code to use for the background.
            Defaults to `'#ffffff'` (`mpl` only)
        fontsize (int): The font size to use for text. Defaults to 13 (`mpl`
            only)
        subfontsize (int): The font size to use for subtext. Defaults to 8
            (`mpl` only)
        displaytext (dict): A dictionary of the text to use for each element
            type in the output visualization. The default values are:
            {
                'id': 'id',
                'u0': 'U_0',
                'u1': 'U_1',
                'u2': 'U_2',
                'u3': 'U_3',
                'x': 'X',
                'y': 'Y',
                'z': 'Z',
                'h': 'H',
                's': 'S',
                'sdg': 'S^\\dagger',
                't': 'T',
                'tdg': 'T^\\dagger',
                'rx': 'R_x',
                'ry': 'R_y',
                'rz': 'R_z',
                'reset': '\\left|0\\right\\rangle'
            }
            You must specify all the necessary values if using this. There is
            no provision for passing an incomplete dict in. (`mpl` only)
        displaycolor (dict): The color codes to use for each circuit element.
            By default all values default to the value of `gatefacecolor` and
            the keys are the same as `displaytext`. Also, just like
            `displaytext` there is no provision for an incomplete dict passed
            in. (`mpl` only)
        latexdrawerstyle (bool): When set to True enable latex mode which will
            draw gates like the `latex` output modes. (`mpl` only)
        usepiformat (bool): When set to True use radians for output (`mpl`
            only)
        fold (int): The number of circuit elements to fold the circuit at.
            Defaults to 20 (`mpl` only)
        cregbundle (bool): If set True bundle classical registers (`mpl` only)
        showindex (bool): If set True draw an index. (`mpl` only)
        compress (bool): If set True draw a compressed circuit (`mpl` only)
        figwidth (int): The maximum width (in inches) for the output figure.
            (`mpl` only)
        dpi (int): The DPI to use for the output image. Defaults to 150 (`mpl`
            only)
        margin (list): `mpl` only
        creglinestyle (str): The style of line to use for classical registers.
            Choices are `'solid'`, `'doublet'`, or any valid matplotlib
            `linestyle` kwarg value. Defaults to `doublet`(`mpl` only)