## A little mathematics for Valentine’s day

This is not a serious post but then mathematics doesn’t have to be serious all the time does it? Ever wondered what the equation of a 3D heart looks like? An old post of mine will help you find the answer using Mathematica. Click on the image for more details (and a demonstration that you can run using the free Mathematica player).

I don’t save all of my love for Mathematica though. I’ve got some for MATLAB too:

%code to plot a heart shape in MATLAB %set up mesh n=100; x=linspace(-3,3,n); y=linspace(-3,3,n); z=linspace(-3,3,n); [X,Y,Z]=ndgrid(x,y,z); %Compute function at every point in mesh F=320 * ((-X.^2 .* Z.^3 -9.*Y.^2.*Z.^3/80) + (X.^2 + 9.* Y.^2/4 + Z.^2-1).^3); %generate plot isosurface(F,0) view([-67.5 2]);

Did you know that the equation for a heart (or a cardioid if you want to get technical) is very similar to the equation for a flower? The polar equation you need is and you get a rotated cardioid for n=1. Change n to 6 and you get a flower. Let’s use the free maths package, SAGE, this time.

First, define the function:

def eqn(x,n): return(1-sin(n*x))

then plot it for n=1

polar_plot(eqn(x,1), (x,-pi, pi),aspect_ratio=1,axes=False)

and for n=7

polar_plot(eqn(x,7), (x,-pi, pi),aspect_ratio=1,axes=False)

Back to Mathematica and the Wolfram Demonstrations project. We have a Valentine’s version of the traditional Tangram puzzle.

Feel free to let me know of any other Valentine’s math that you discover, puzzles, fractals or equations, it’s all good :)

**Update Feb 14th 2011**

Mariano Beguerisse Díaz sent me some MATLAB code that uses a variation on the standard mandelbrot and I turned it into the movie below. His original code is in the comments section

I have a ‘fuzzy’ Mandelbrot fractal in MATLAB

Just run this script, have a go!

That’s nice :)