Program to create equation from drawing a graph

Question

I was wondering if anyone knows a program that could make an equation from having someone just drawing the plot.

Example: I would like to just draw an image then have the program give me the equation below. Is such a thing possible?

Equation given after drawing the plot.
x=16*sin(s)^3
y=13*cos(s)-6*cos(2*s)-2*cos(3*s)-cos(4*s)
-pi<s<pi step=.01

enter image description here

link to plot

@m_power in the end it will be a set of points because the drawing has to be converted to x and y values, but I was wondering if a program was already out there. — Rick T, Feb 14 '14 at 13:34
@Jigg hahah In the spirit of today that was the example I chose to use — Rick T, Feb 14 '14 at 14:30
May be relevant: https://math.stackexchange.com/questions/1449035/drawing-a-picture-with-equations — NoChance, Jun 08 '18 at 02:14

score 1 · Accepted Answer · answered Feb 14 '14 at 13:06

1

You should use some parametrized class of curves and fit them to the current drawing. Usually you use splines in this context. If you like to allow corners you should introduce some corner detection and work with piecewise splines.

answered Feb 14 '14 at 13:06

matheburg

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score 0 · Answer 2 · answered Feb 14 '14 at 17:36

You should search for Interpolation methods and choose which ever that best suits you. A good point for start would be Interpolation.

Fortunately most of those methods are built-in function in MATLAB. You can also check some results and comparison of splines methods in here Splines.

Program to create equation from drawing a graph

2 Answers2