Semi-Colon not supressing output

Hello,

I was wondering if someone would be able to help me. I wrote this code for the bisection method:

Z=[0.126938541068352,0.182653647329121,0.209649626651350,0.284893739230327,0.132107983917289,0.0637564618035612];
K=[4.23297333098727;1.43244396950094;1.92283427118344;0.505474641398215;0.638916861313215;0.183249967140241];
a = 0;
b = 1;
accuracy = 0.00000001;
if RRE(a,Z,K) == 0; %Checks if lower bound is the root. a is already the root.
    Ps = a;
elseif RRE(b,Z,K) == 0; %Checks if the upper bound is the root b is already the root.
    Ps = b;
elseif RRE(a,Z,K)*RRE(b,Z,K) > 0; 
    error('RRE(a) and RRE(b) do not have opposite signs. Try a different bound or check if your Z and K values are correct.'); %custom error code
end
while (b-a > accuracy || (abs(RRE(a,Z,K)) > accuracy && abs(RRE(b,Z,K)) > accuracy)); %repeat the bisection method until both f(a) and f(b) are less than 'accuracy' or until the difference between a and b are less than 'accuracy'
     c = (a+b)/2; %Midpoint Method
    %c = a - (((b-a)*RRE(a,Z,K))/(RRE(b,Z,K)-RRE(a,Z,K))); %False-Position Method

       if RRE(c,Z,K) == 0;
           Ps = c;
           break;
       elseif RRE(a,Z,K)*RRE(c,Z,K) < 0; %If f(a)*f(c) is a negative # then make the next range from [a c]. To do this you make c the new b
           b = c;
       else
           a = c; %If f(a)*f(c) is a posituve # then make the next range from [c b]. To do this you make c the new a value
       end
  end
if RRE(c,Z,K) == 0;
    Ps = c;
elseif RRE(a,Z,K)<RRE(b,Z,K); %Choose the x-value that brings f(psi) closest to 0.
    Ps = a;
else
    Ps = b;
end

However, when I run this code my function RRE is calculating a value AND printing it out on the command window. I've checked all my semi-colons and all the lines are supressed. I'm stuck. I have no idea why my function RRE is printing to the command window.

Please help.

-Justin

[Guillaume]

The problem is most likely with the RRE function then, not the code calling it.

Note that you don't usually put a semicolon at the end of a while or if statement. It does not make a difference in matlab but would be an error in other languages (mostly C-based) and just look odds.

[Image Analyst]

Did you include the RRE function so we can run your code?

[John D'Errico]

You did not give us the function RRE. The problem is most likely in there.

By the way, I want to really compliment you on the use of internal comments. They make your code far more debuggable. So a good job there. I also like that you have error checking in the code.

You might consider using more expressive variable names though. They also make code more readable, more debuggable.