d3¶
d3 is another popular DOM manipulation library available in JavaScript. This is the domonic-side Python port of that surface.
It has several utilities for working with the DOM.
selection¶
d3’s selection API is very powerful.
from domonic.dom import *
from domonic.html import *
from domonic.d3.selection import *
import domonic.d3 as d3
format¶
d3’s has a library for formatting numbers to avoid things like floating precision
from domonic.dom import *
from domonic.html import *
from domonic.d3.format import *
from domonic.d3.format import format
dispatch¶
d3 has an event system
from domonic.dom import *
from domonic.html import *
from domonic.d3.dispatch import dispatch, Dispatch
path¶
d3’s path API converts SVG paths to a d3.path object which is compatible with canvas.
from domonic.svg import *
from domonic.d3.path import Path
polygon¶
d3’s has shape API
from domonic.d3.polygon import *
D3 expects a “polygon” is a 2D array of integers listed counterclockwise (clockwise works too). This does not work with the polygon as defined by SVG, SVG polygons have a points method you can parse into a 2D array and use here.
polygonArea() finds the area of a given polygon. It returns a float/int.
def test_polygonArea(self):
irreg_0 = [[5,11],[12,4],[7,7],[6,1]] # area: 15
irreg_1 = [[-6,12],[23,2],[19,-8],[-7,-6]] # area: 400
irreg_2 = [[0,4],[12,8],[23,-5],[-5,-3]] # area: 203
square = [[0,4],[4,4],[4,0],[0,0]] # area: 16
triangle = [[-4,0],[0,4],[2,0]] # area: 12
self.assertEqual(polygonArea(irreg_0), 15)
self.assertEqual(polygonArea(irreg_1), 400)
self.assertEqual(polygonArea(irreg_2), 203)
self.assertEqual(polygonArea(square), 16)
self.assertEqual(polygonArea(triangle), 12)
polygonCentroid() finds the center of mass of a given polygon. It returns 2 ints in an array, representing the point of the polygons center of mass.
def test_polygonCentroid(self):
irreg = [[-4,0],[8,12],[4,8],[-4,-4],[0,0]] # centroid: [0, 4]
square = [[0,4],[4,4],[4,0],[0,0]] # centroid: [2, 2]
triangle = [[-4,0],[0,4],[4,2]] # centroid: [0, 2]
self.assertEqual(polygonCentroid(irreg), [0, 4])
self.assertEqual(polygonCentroid(square), [2, 2])
self.assertEqual(polygonCentroid(triangle), [0, 2])
polygonHull() takes a 2D array of points and determines the polygon hull using andrew’s monotone chain algorithm. It returns the polygon hull as a 2D array of points.
def test_polygonHull(self):
points_0 = [[0,6],[12,8],[23,-5],[-5,-3],[5,11],[12,4],[7,7],[6,1]]
points_1 = [[-4,0],[8,12],[4,8],[-4,-4],[0,0],[-6,12],[23,2],[19,-8],[-7,-6]]
hull_0 = [[-5,-3],[0,6],[5,11],[12,8],[23,-5]]
hull_1 = [[-7,-6],[-6,12],[8,12],[19,-8],[23,2]]
self.assertEqual(polygonHull(points_0), hull_0)
self.assertEqual(polygonHull(points_1), hull_1)
polygonContains() takes a polygon and a point, it returns true if the point is inside the polygon, false otherwise.
def test_polygonContains(self):
irreg_0 = [[5,11],[12,4],[7,7],[6,1]]
square = [[0,4],[4,4],[4,0],[0,0]]
triangle = [[-4,0],[0,4],[2,0]]
self.assertTrue(polygonContains(irreg_0, [6,8]))
self.assertFalse(polygonContains(irreg_0, [0,0]))
self.assertTrue(polygonContains(square, [2,2]))
self.assertFalse(polygonContains(square, [-2,-2]))
self.assertTrue(polygonContains(triangle, [0,1]))
self.assertFalse(polygonContains(triangle, [0,-1]))
polygonLength() takes a polygon and returns the sum of the length of the polygon’s sides.
def test_polygonLength(self):
irreg_0 = [[5,11],[12,4],[7,7],[6,1]] # length = 31.863
square = [[0,4],[4,4],[4,0],[0,0]] # length = 16
triangle = [[-4,0],[0,4],[2,0]] # length ~ 16.129
self.assertEqual(round(polygonLength(irreg_0), 3), 31.863)
self.assertEqual(polygonLength(square), 16)
self.assertEqual(round(polygonLength(triangle), 3), 16.129)
