exp_ellipse.py

# -*- coding: utf-8 -*- 

'''
Author : 高斯羽 博士 (Dr. GAO, Siyu)

Version : 1.0.0

Last Modified : 2019-04-22

This script is an example to demonstration how to use the "curlyBrace" module to 
plot curly brackets using matplotlib.

This example demonstrate annotating two pairs of ellipses.

The parametric equation of ellipse can be found:
https://stackoverflow.com/questions/10952060/plot-ellipse-with-matplotlib-pyplot-python
'''

import matplotlib.pyplot as plt
import numpy as np
from curlyBrace import curlyBrace
import os

# fig save control
bool_savefig = False

# figure size and dpi
dbl_width   = 1000.0
dbl_height  = 800.0
dbl_dpi     = 100.0

# line width and colour for the ellipses
lw = 2
color='royalblue'

u = 0.0  # x-position of the centre
v = 0.0  # y-position of the centre
a1 = 2.0  # radius on the x-axis for ellipse 1
b1 = 1.5  # radius on the y-axis for ellipse 1
a2 = 7.0  # radius on the x-axis for ellipse 2
b2 = 5.5  # radius on the y-axis for ellipse 2

theta = np.linspace(0, 2.0 * np.pi, 101)

x1 = u + a1 * np.cos(theta)
y1 = v + b1 * np.sin(theta)
x2 = u + a2 * np.cos(theta)
y2 = v + b2 * np.sin(theta)

fig, axes = plt.subplots(2, 1, figsize=(dbl_width / dbl_dpi, dbl_width / dbl_dpi), dpi=dbl_dpi)

# fontdict for axis titles
font = {'family': 'Arial',
        'color':  'k',
        'weight': 'bold',
        'style': 'normal',
        'size': 12,
        }

str_title1 = 'Example: Axes aspect equal, auto scale off'
str_title2 = 'Example: Axes aspect equal, auto scale on'

axes[0].plot(x1, y1, lw=lw, color=color)
axes[0].plot(x2, y2, lw=lw, color=color)
axes[1].plot(x1, y1, lw=lw, color=color)
axes[1].plot(x2, y2, lw=lw, color=color)

axes[0].set_aspect('equal', 'box')
axes[0].grid(color='lightgray', linestyle='--')
axes[0].set_title(str_title1, fontdict=font)
axes[1].set_aspect('equal', 'box')
axes[1].grid(color='lightgray', linestyle='--')
axes[1].set_title(str_title2, fontdict=font)

# bracket coefficient
k_r = 0.1

# points for the brackets
phi = np.linspace(0, 2.0 * np.pi, 13)

x1 = u + a1 * np.cos(phi)
y1 = v + b1 * np.sin(phi)
x2 = u + a2 * np.cos(phi)
y2 = v + b2 * np.sin(phi)

# fontdict for the brackets
font = {'family': 'serif',
        'color':  'darkred',
        'weight': 'normal',
        'style': 'normal',
        'size': 8,
        }

# bracket line width and colour
lw = 3
color1 = 'r'
color2 = 'darkorange'

for i in range(0, len(x1)):

    p1 = [x1[i], y1[i]]
    p2 = [x2[i], y2[i]]

    str_text = 'Epllise\nanti-clockwise'

    curlyBrace(fig, axes[0], p1, p2, k_r, bool_auto=False, str_text=str_text, color=color1, lw=lw, int_line_num=3, fontdict=font)

for i in range(0, len(x1)):

    p1 = [x2[i], y2[i]]
    p2 = [x1[i], y1[i]]

    str_text = 'Epllise\nclockwise'

    curlyBrace(fig, axes[1], p1, p2, k_r, bool_auto=True, str_text=str_text, color=color2, lw=lw, int_line_num=3, fontdict=font)

if bool_savefig:

    str_filename = os.path.basename(__file__)[:-3] + '.png'

    str_filename = os.path.join(os.getcwd(), str_filename)

    fig.savefig(str_filename, bbox_inches='tight', dpi=300)

else:

    pass

plt.show()