How to get an equation from an already plotted graph in matlab

clear all
clc 
T = readtable('data1.xlsx') ; 
T = table2array(T) ;
x = T(1,2:end);  % coil length
y = T(2:end,1);  % magnitude length
Z = T(2:end,2:end);  % use fillmissing to fill NaNs
[X,Y] = meshgrid(x,y) ;
[xq,yq] = meshgrid(2:0.1:10);     % grid interval 0.1
Zq = interp2(x,y,Z,xq,yq,'spline'); % we use spline   cubic, makima also available

figure
AA = surf(xq,yq,Zq);
title('(spline,cubic,makima) Interpolation Using Finer Grid');

I got the attached graph using the above code. (The 'data.xlsx' required when creating the code is also attached.)

I am trying to get an equation (function) from an already plotted graph, please help me with the code

Answer 1

[Image Analyst]

I don't think you can. You can probably get the numerical data out, but the equation -- I don't think so. For a simple example, visualize a sine wave. And you want the sine wave equation out - well what if you got a sine wave equation but the user actually plotted a cosine wave with a phase shift so that it looks, and is, identical yet has a completely different equation.

[kyungdoo lee]

Thank you for the reply