Having errors with my code and not quite sure how to fix it. As you can probably see from the code below, I am calling the values f and df from two other files. The code directly below this is stored in a file called NRM2016.m whereas the f variable and df variable are stored in funct.m and dfunct.m respectively.
What I am trying to do is allow the users to input an initial guess and an initial accuracy. The code then stores this and applies it to the function and its differential and then store it to a text file. (the writing to text file isn't an issue so I have omitted the code: as ignore the 'if true' part that starts the code below that isn't there in the original)
1: Main Script
if true
xinit = input('Enter a value for initial guess (Xo):');
epsilon = input('Enter a value for the required accuracy (Eps):');
x = xinit;
xold = xinit;
for i = 0:inf
x = x-f/df;
error = abs(x-xold);
xold = x;
if(error<epsilon)
break;
end
end
2: Funct.m & dfunct.m's contents
syms x
f = x^3 + 11*x^2 + 4*x - 60;
df = diff(y,x);
I am taking the initial value as 1.8 to begin with and the required accuracy as 1e-13 however it just isn't working. The differential is working fine as well as the input variables. I just don't know why it isn't doing Newton Raphson Method correctly. Can anyone help? thanks
