gbox 0.1.1

Geometry Box: A simple package for working with basic geometry shapes

gbox: Geometry Box

A simple Python package for geometrical operations.

Installation

pip install gbox

Quick Introduction

import gbox as gb

circle = gb.Circle(radius=2.0, cent=(3.0, 6.0))
print(circle.area)  # prints circle area
print(circle.perimeter)  # prints circle perimeter
circle.shape_factor()  # returns shape factor: perimeter/equivalent circle perimeter.
print(circle.locus)  # prints 50 points along the locus of circle  
# one can set the desired number of locus points as
circle.num_locus_points = 251
print(circle.locus)  # prints 251 points along the locus of the circle
circle.plot()  # plots a circle displays using `matplotlib.pyplot.show()`
circle.plot(f_path='/path/to/file')  # saves a plot at the specified path
#
import matplotlib.pyplot as plt

fig, axs = plt.subplots()
circle.plot(axis=axs)  # plots circle on the axs object

A sample code for plotting various shapes

import gbox as gb
from os import path
import matplotlib.pyplot as plt

fig, axs = plt.subplots(2, 4)
gb.Circle().plot(axis=axs[0, 0])
gb.Ellipse().plot(axis=axs[0, 1])
gb.RegularPolygon(3).plot(axis=axs[0, 2])
gb.Rectangle().plot(axis=axs[0, 3])
gb.BoundingBox2D().plot(axis=axs[1, 0])
gb.CShape().plot(axis=axs[1, 1])
gb.Capsule().plot(axis=axs[1, 2])
gb.NLobeShape(3).plot(axis=axs[1, 3])
plt.tight_layout()
plt.savefig(path.join(path.dirname(__file__), "shapes.pdf"))
plt.close()

It produces the following figure.

All methods

Points

Methods for working with points (at present in a plane)

import gbox as gb
from numpy import array, pi

points = gb.Points(array([[2.0, 3.0], [6.0, 6.5], [5.0, 8.0]]))
print(points.x)  # x coordinates of points
print(points.y)  # y coordinates of points
print(len(points))  # 3, i.e., number of points
print(points.dim)  # 2, i.e., the dimensions x and y
points.append(array([[44.0, -5.0], ]), end=True)  # appends points at the end
points.append(array([[44.0, -5.0], ]), end=False)  # appends points at the beginning
points.close_loop()  # appends first point at the end 
points.transform(angle=1.5 * pi, dx=-2.5, dy=-4.1)  # rotates points in CCW direction by `angle=1.5 * pi` and
# translates points by `dx` and `dy` along the `x` and `y` directions.
points.reverse()  # reverses the order of points
points.reflect(p1=(0.0, 5.0), p2=(-8.0, 1.0))  # reflects the points about the line joining `p1` and `p2`

Curves

Methods for working with curves (at present in a plane)

import gbox as gb
from numpy import pi

line = gb.StraightLine(length=1.0, start_point=(2.0, 3.0), angle=pi / 2)
# Creates straight line starting at a given point, of a given length and aligned at an angle with the positive x-axis
line.num_locus_points = 200  # set the number of points along the locus, defaults to 100
print(line.locus)  # points: Points along the locus of the line
#
ell_arc = gb.EllipticalArc(
    smj=2.0, smn=1.0, theta_1=0.25 * pi, theta_2=0.6 * pi, centre=(1.0, -5.0), smj_angle=0.45 * pi
)
# Creates an elliptical arc with specified `centre`, semi major and minor axes of lengths 2.0 and 1.0, 
# starting from `theta_1` to `theta_2` (w.r.t semi major axis) and the inclination of semi major axis `smj_angle`.
print(ell_arc.locus)
# points of arc along the locus, default to 100 point which can be set by `ell_arc.num_locus_points`  
#
cir_arc = gb.CircularArc(r=2.5, theta_1=0.0 * pi, theta_2=1.25 * pi, centre=(2.0, 4.0))
# Creates a circular arc with radius `r`, starting from `theta_1` and ending at `theta_2`

Closed Shapes

Methods for working with curves (at present in a plane). For all the shapes the following four common properties are defined

• locus: Points kind of object containing the points along the locus of the shape. The number of points defaults to 100 but can be set to a desired number.
• area: Enclosed area of the respective shape
• perimeter: Perimeter of the respective shape
• shape_factor: A non-dimensional number used to quantify the non-circularity of the shape. It is defined as the ratio of the respective shape perimeter to the perimeter of the circle containing equivalent area.

Goals

• Convert Points(list) to Points(numpy.ndarray) and see if there is any performance gain
• Optimize the shapes list operations and storage