Added check for the correct number of variables and added a few comments

Secant.m

@@ -4,16 +4,23 @@ function [xList, errorList] = Secant(f, p0, p1, errorAllowed)
 %This function find the root of a function using the Secant Method
 %
 
+	%Make sure the number of arguments is correct
+	if(narginchk(4,4))
+		error('That is an incorrect number of arguments')
+	end
+	%A few necesary things before we get started
 	pkg load symbolic;
 	warning('off','OctSymPy:sym:rationalapprox');
+	%Constant variables
 	maxIt = 50;
+	%Variables
 	cnt = 2;
 	q0 = double(subs(f,p0));
 	q1 = double(subs(f,p1));
 	currentError = errorAllowed + 1;
 	p = 0;
 
-
+	%Loop until you find an answer within error or you reach the maximum number of itterations
 	while((cnt <= maxIt) && (currentError >= errorAllowed))
 		p = p1 - (q1 * (p1 - p0))/(q1 - q0);
 		currentError = abs(p - p1);