Answer to Question #294481 in Python for david

Question

Make 3D heart with Happy Valentine's Day inside using python code

Answer 1

'''
===============================================================
3D heart shape with Happy Valentine's Day inside in matplotlib
===============================================================
Demonstrates how to plot a 3D function in cartesian coordinates.
Uses the marching cubes algorithm in scikit-image to obtain a isosurface.
'''


from mpl_toolkits.mplot3d import Axes3D
from matplotlib import pyplot as plt
import numpy as np
from skimage import measure




# Set up mesh
n = 100 


x = np.linspace(-3,3,n)
y = np.linspace(-3,3,n)
z = np.linspace(-3,3,n)
X, Y, Z =  np.meshgrid(x, y, z)


# Create cardioid function 
def f_heart(x,y,z):
    F = 320 * ((-x**2 * z**3 -9*y**2 * z**3/80) +
               (x**2 + 9*y**2/4 + z**2-1)**3)
    return F


# Obtain value to at every point in mesh
vol = f_heart(X,Y,Z) 


# Extract a 2D surface mesh from a 3D volume (F=0)
verts, faces, normals, values = measure.marching_cubes_lewiner(vol, 0,  spacing=(0.1, 0.1, 0.1))




# Create a 3D figure
fig = plt.figure(figsize=(12,8))
ax = fig.add_subplot(111, projection='3d')


# Plot the surface
ax.plot_trisurf(verts[:, 0], verts[:,1], faces, verts[:, 2],
                cmap='Spectral', lw=1)


# Change the angle of view and title
ax.view_init(15, -15)


# ax.set_title(u"Made with ❤ (and Python)", fontsize=15) # if you have Python 3
ax.set_title("Made with <3 (and Python)", fontsize=15)


# place a text box in upper left in axes coords
ax.text("Happy Valentines Day", 0.50, 0.50, textstr, transform=ax.transAxes, fontsize=15,
        verticalalignment='centre')


# Show me some love ^^
plt.show()




'''
==================================================================
The commented code below creates a 2D Heart with valentines inside
==================================================================


# Python3 code to print happy valentine's
# day
import math


n = 10


# Initializing String to print in heart
message = " HappY Valentines DaY "


# Position from where from top
# message box would be placed.
print_message = 4


# Add space if message length is odd
if (len(message) % 2 != 0):
	message += " "


# Outer loop to adjust length of upper
# part message is not handled in this part
for a in range(n):
	
	# To print space and variable accordingly
	for b in range(4 * n + 1):
		
		# Computing distance to print variable
		distance1 = math.sqrt(pow(a - n, 2) +
							pow(b - n, 2))
		distance2 = math.sqrt(pow(a - n, 2) +
							pow(b - 3 * n, 2))
							
		if (distance1 < n + 0.5 or
			distance2 < n + 0.5):
			print("S", end = "")
		else:
			print(" ", end = "")


	# Ending line after each iteration
	print()


# Printing the message part and lower
# part of heart. Outer loop handles
# depth of the heart.
for a in range(1, 2 * n):


	# For getting the lower curve of heart
	for b in range(a):
		print(" ", end = "")
		
	# Inner loop
	# handles the message and spaces accordingly
	for b in range(4 * n + 1 - 2 * a):
		
		# Checks if the height is in range of
		# message space
		if (a >= print_message - 1 and
			a <= print_message + 1):
			point = b - (4 * n - 2 *
					a - len(message)) // 2


			# Prints message after leaving
			# appropriate space
			if (point < len(message) and point >= 0):
				if (a == print_message):
					print(message[point], end = "")
				else:
					print(" ", end = "")
			else:
				print("S", end = "")


		else:
			print("S", end = "")


	print()


# This code is contributed by subhammahato348
'''