Nerdy Valentine’s in Python, R, and Matlab

Let’s celebrate Valentine’s Day with some nerdy love! In this post, we will create heart-shaped plots using Python, R, and Matlab. These heart-shaped plots are a fun and creative way to express your love for programming and data visualization. Let’s get started!

Python

Here is a Python code snippet to plot a 3D heart shape using Matplotlib:

from mpl_toolkits.mplot3d import Axes3D
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter
import matplotlib.pyplot as plt
import numpy as np


def heart_3d(x, y, z):
    return (
        (x**2 + (9 / 4) * y**2 + z**2 - 1) ** 3 - x**2 * z**3 - (9 / 80) * y**2 * z**3
    )


bbox = (-1.5, 1.5)

xmin, xmax, ymin, ymax, zmin, zmax = bbox * 3
fig = plt.figure()

ax = fig.add_subplot(111, projection="3d")
A = np.linspace(xmin, xmax, 100)  # resolution of the contour
B = np.linspace(xmin, xmax, 40)  # number of slices
A1, A2 = np.meshgrid(A, A)  # grid on which the contour is plotted

for z in B:  # plot contours in the XY plane
    X, Y = A1, A2
    Z = heart_3d(X, Y, z)
    cset = ax.contour(X, Y, Z + z, [z], zdir="z", colors=("r",))

for y in B:  # plot contours in the XZ plane
    X, Z = A1, A2
    Y = heart_3d(X, y, Z)
    cset = ax.contour(X, Y + y, Z, [y], zdir="y", colors=("r",))

for x in B:  # plot contours in the YZ plane
    Y, Z = A1, A2
    X = heart_3d(x, Y, Z)
    cset = ax.contour(X + x, Y, Z, [x], zdir="x", colors=("r",))

_ = ax.set_zlim3d(zmin, zmax);
_ = ax.set_xlim3d(xmin, xmax);
_ = ax.set_ylim3d(ymin, ymax);

ax.xaxis.set_pane_color((1.0, 1.0, 1.0, 0.0))
ax.yaxis.set_pane_color((1.0, 1.0, 1.0, 0.0))
ax.zaxis.set_pane_color((1.0, 1.0, 1.0, 0.0))


plt.show()

Figure 1: 3D heart shape plotted in Python using Matplotlib

R

In R, we can use the rgl and misc3d packages to create 3D mesh plots. Here is the R code to plot a heart shape:

options(rgl.useNULL = TRUE) # Use NULL device if display is not available

library(misc3d)
library(rgl)

heart_3d <- function(x, y, z) {
  (x^2 + (9 / 4) * y^2 + z^2 - 1)^3 - x^2 * z^3 - (9 / 80) * y^2 * z^3
}

# Create a grid of points in 3D space
x <- seq(-1.5, 1.5, length.out = 50)
y <- seq(-1.5, 1.5, length.out = 50)
z <- seq(-1.5, 1.5, length.out = 50)

# Generate 3D grid of function values
grid <- expand.grid(x = x, y = y, z = z)
values <- with(grid, heart_3d(x, y, z))

# Reshape to 3D array for contour3d
dim_values <- c(length(x), length(y), length(z))
values <- array(values, dim = dim_values)

# Create 3D contour plot
contour3d(values,
  level = 0,
  x = x, y = y, z = z, col.mesh = "red", alpha = 0.5, engine = "grid"
)

Figure 2: 3D heart shape plotted in R using rgl and misc3d packages (looks strange but this is the best I could do)

Matlab

The code for plotting 3D shape in Matlab is much more laconic than in Python or R. Here is how to plot a heart shape in Matlab:


% volume data
step = 0.05;
[X,Y,Z] = meshgrid(-3:step:3, -3:step:3, -3:step:3);
F = (-(X.^2).*(Z.^3)-(9/80).*(Y.^2).*(Z.^3))+((X.^2)+(9/4).*(Y.^2)+(Z.^2)-1).^3;

% wireframe
patch(isosurface(X,Y,Z,F,0), 'FaceColor','w', 'EdgeColor','r')
daspect([1 1 1])
view(3)
axis tight equal
set(gcf, 'Color','w')

Figure 3: The Matlab code is the most concise of the three, and the plot it produces is interactive in the Matlab IDE

Now you have three beautiful heart-shaped plots created using Python, R, and Matlab. Share these plots with your loved ones and spread the nerdy love this Valentine’s Day!

Python

R

Matlab

See Also