There are a number of mathematical curves that produced heart shapes and you can find many tools on the web.
The author presents himself with a brief introduction:
Eric W. Weisstein began compiling scientific encyclopedias as a high school student nearly twenty years ago. Born in Bloomington, Indiana in 1969, Weisstein studied physics and astronomy at Cornell University and Caltech and received his Ph.D. from Caltech in 1996. In 1995, Weisstein took the vast collection of mathematical facts that he had been accumulating since his teenage years and began to deploy them on the early internet. These pioneering efforts at organizing and presenting online content helped define a paradigm that has subsequently been followed by other large-scale informational projects on the web.
The most important part of this resource is highlighted in a table of contents about mathematical issues:
- Algebra
- Applied Mathematics
- Calculus and Analysis
- Discrete Mathematics
- Foundations of Mathematics
- Geometry
- History and Terminology
- Number Theory
- Probability and Statistics
- Recreational Mathematics
- Topology
If you want to use the Wolfram Alpha syntax, there are formulas:
heart curve