diff --git a/galleries/examples/specialty_plots/ishikawa_diagram.py b/galleries/examples/specialty_plots/ishikawa_diagram.py new file mode 100644 index 000000000000..18761ca36043 --- /dev/null +++ b/galleries/examples/specialty_plots/ishikawa_diagram.py @@ -0,0 +1,203 @@ +""" +================ +Ishikawa Diagram +================ + +Ishikawa Diagrams, fishbone diagrams, herringbone diagrams, or cause-and-effect +diagrams are used to identify problems in a system by showing how causes and +effects are linked. +Source: https://en.wikipedia.org/wiki/Ishikawa_diagram + +""" +import matplotlib.pyplot as plt + +from matplotlib.patches import Polygon, Wedge + +# Create the fishbone diagram +fig, ax = plt.subplots(figsize=(10, 6), layout='constrained') +ax.set_xlim(-5, 5) +ax.set_ylim(-5, 5) +ax.axis('off') + + +def problems(data: str, + problem_x: float, problem_y: float, + prob_angle_x: float, prob_angle_y: float): + """ + Draw each problem section of the Ishikawa plot. + + Parameters + ---------- + data : str + The category name. + problem_x, problem_y : float, optional + The `X` and `Y` positions of the problem arrows (`Y` defaults to zero). + prob_angle_x, prob_angle_y : float, optional + The angle of the problem annotations. They are angled towards + the tail of the plot. + + Returns + ------- + None. + + """ + ax.annotate(str.upper(data), xy=(problem_x, problem_y), + xytext=(prob_angle_x, prob_angle_y), + fontsize='10', + color='white', + weight='bold', + xycoords='data', + verticalalignment='center', + horizontalalignment='center', + textcoords='offset fontsize', + arrowprops=dict(arrowstyle="->", facecolor='black'), + bbox=dict(boxstyle='square', + facecolor='tab:blue', + pad=0.8)) + + +def causes(data: list, cause_x: float, cause_y: float, + cause_xytext=(-9, -0.3), top: bool = True): + """ + Place each cause to a position relative to the problems + annotations. + + Parameters + ---------- + data : indexable object + The input data. IndexError is + raised if more than six arguments are passed. + cause_x, cause_y : float + The `X` and `Y` position of the cause annotations. + cause_xytext : tuple, optional + Adjust to set the distance of the cause text from the problem + arrow in fontsize units. + top : bool + + Returns + ------- + None. + + """ + for index, cause in enumerate(data): + # First cause annotation is placed in the middle of the problems arrow + # and each subsequent cause is plotted above or below it in succession. + + # [, [, ]] + coords = [[0, [0, 0]], + [0.23, [0.5, -0.5]], + [-0.46, [-1, 1]], + [0.69, [1.5, -1.5]], + [-0.92, [-2, 2]], + [1.15, [2.5, -2.5]]] + if top: + cause_y += coords[index][1][0] + else: + cause_y += coords[index][1][1] + cause_x -= coords[index][0] + + ax.annotate(cause, xy=(cause_x, cause_y), + horizontalalignment='center', + xytext=cause_xytext, + fontsize='9', + xycoords='data', + textcoords='offset fontsize', + arrowprops=dict(arrowstyle="->", + facecolor='black')) + + +def draw_body(data: dict): + """ + Place each section in its correct place by changing + the coordinates on each loop. + + Parameters + ---------- + data : dict + The input data (can be list or tuple). ValueError is + raised if more than six arguments are passed. + + Returns + ------- + None. + + """ + second_sections = [] + third_sections = [] + # Resize diagram to automatically scale in response to the number + # of problems in the input data. + if len(data) == 1 or len(data) == 2: + spine_length = (-2.1, 2) + head_pos = (2, 0) + tail_pos = ((-2.8, 0.8), (-2.8, -0.8), (-2.0, -0.01)) + first_section = [1.6, 0.8] + elif len(data) == 3 or len(data) == 4: + spine_length = (-3.1, 3) + head_pos = (3, 0) + tail_pos = ((-3.8, 0.8), (-3.8, -0.8), (-3.0, -0.01)) + first_section = [2.6, 1.8] + second_sections = [-0.4, -1.2] + else: # len(data) == 5 or 6 + spine_length = (-4.1, 4) + head_pos = (4, 0) + tail_pos = ((-4.8, 0.8), (-4.8, -0.8), (-4.0, -0.01)) + first_section = [3.5, 2.7] + second_sections = [1, 0.2] + third_sections = [-1.5, -2.3] + + # Change the coordinates of the annotations on each loop. + for index, problem in enumerate(data.values()): + top_row = True + cause_arrow_y = 1.7 + if index % 2 != 0: # Plot problems below the spine. + top_row = False + y_prob_angle = -16 + cause_arrow_y = -1.7 + else: # Plot problems above the spine. + y_prob_angle = 16 + # Plot the 3 sections in pairs along the main spine. + if index in (0, 1): + prob_arrow_x = first_section[0] + cause_arrow_x = first_section[1] + elif index in (2, 3): + prob_arrow_x = second_sections[0] + cause_arrow_x = second_sections[1] + else: + prob_arrow_x = third_sections[0] + cause_arrow_x = third_sections[1] + if index > 5: + raise ValueError(f'Maximum number of problems is 6, you have entered ' + f'{len(data)}') + + # draw main spine + ax.plot(spine_length, [0, 0], color='tab:blue', linewidth=2) + # draw fish head + ax.text(head_pos[0] + 0.1, head_pos[1] - 0.05, 'PROBLEM', fontsize=10, + weight='bold', color='white') + semicircle = Wedge(head_pos, 1, 270, 90, fc='tab:blue') + ax.add_patch(semicircle) + # draw fishtail + triangle = Polygon(tail_pos, fc='tab:blue') + ax.add_patch(triangle) + # Pass each category name to the problems function as a string on each loop. + problems(list(data.keys())[index], prob_arrow_x, 0, -12, y_prob_angle) + # Start the cause function with the first annotation being plotted at + # the cause_arrow_x, cause_arrow_y coordinates. + causes(problem, cause_arrow_x, cause_arrow_y, top=top_row) + + +# Input data +categories = { + 'Method': ['Time consumption', 'Cost', 'Procedures', 'Inefficient process', + 'Sampling'], + 'Machine': ['Faulty equipment', 'Compatibility'], + 'Material': ['Poor-quality input', 'Raw materials', 'Supplier', + 'Shortage'], + 'Measurement': ['Calibration', 'Performance', 'Wrong measurements'], + 'Environment': ['Bad conditions'], + 'People': ['Lack of training', 'Managers', 'Labor shortage', + 'Procedures', 'Sales strategy'] +} + +draw_body(categories) +plt.show()