clc;
clear all;
close all;

load('Idata.mat');  %loading the I(V) data
plot(volt,curr)     %plotting the data
xlabel('Voltage');  %labelling the x axis
ylabel('Current');  %labelling the y axis
title('Current as a function of Voltage   I(V) ') %title for the graph

lv=length(volt);    %Determining the number of voltage values
lc=length(curr);    %determning the number of current values

x1=randi(lv,1);     %This will produce a random voltage value
x2=randi(lc,1);     %This will produce a random current value

y=volt(x1);         %Matches the corresponding value of current value from the randomly selected voltage value
yn=volt(x2);        %Matches the corresponding value of voltage value from the randomly selected current value

p=curr(x1);         %Matches the corresponding value of current value from the randomly selected voltage value
pn=curr(x2);        %Matches the corresponding value of voltage value from the randomly selected current value

while abs(pn-p)>10e-12 % This makes sure the iterrations will only run if the changes are greater than our 'tolerance'

    t=yn-(pn*((yn-y)/(pn-p)));      %This is working out the change in volts over change in current,i.e dy/dx(Gradient), where t would be the y intercepts on the graph
    [a,b]=min(abs(volt-t));         %Returns the minimum element in the array of values

    p=pn;                           % Making the values of voltage and current the same
    pn=curr(b);                     % This will make the voltage equal the current at the minimim point in the array worked out in the line above
    y=yn;                           % Making the value of the randomly selected voltage and current the same.
    yn=t;                           % This is finding the value for which the voltage equals zero ( Voltage Dissapears )
end