I need some assistance with my function program?

I'm not sure where my mistakes are. The following is my main program:

a = input('Enter value for side a: ');  

if a <= 0                           

      disp('Not a valid input! Side "a" must be greater than zero.');break; 

end

b = input('Enter value for side b: ');    

if b <= 0                                 

      disp('Not a valid input! Side "b" must be greater than zero.');break;   

end

c = input('Enter value for side c: ');   

if c <= 0                                 

      disp('Not a valid input! Side "c" must be greater than zero.');break;   

end                                     

if a > b+c                              

      fprintf('\n');                      

      disp('Error: Side "a" must be less than the sum of sides b & c.');break;  

elseif b > a+c                          

      fprintf('\n');                      

      disp('Error: Side "b" must be less than the sum of sides a & c.');break;

elseif c > a+b                          

      fprintf('\n');                      

      disp('Error: Side "c" must be less than the sum of sides a & b.');break;

end

fprintf('\n');                          

[Angle_A,Angle_B,Angle_C] = angle_calc(a,b,c) % This is the correct name of my function program

My function program is:

function [law_cosines] = angle_calc (side_A,side_B,side_C)

angle_A = acosd((b^2+c^2-a^2)/(2*b*c)); 

angle_B = acosd((a^2+c^2-b^2)/(2*a*c)); 

angle_C = acosd((a^2+b^2-c^2)/(2*a*b));

Answer 1

[Image Analyst]

Your "function program" needs to look like this:

function [angle_A, angle_B, angle_C] = angle_calc (a, b, c)
angle_A = acosd((b^2+c^2-a^2)/(2*b*c)); 
angle_B = acosd((a^2+c^2-b^2)/(2*a*c)); 
angle_C = acosd((a^2+b^2-c^2)/(2*a*b));

Answer 2

[Walter Roberson]

Your line

function [law_cosines] = angle_calc (side_A,side_B,side_C)

should be

function [angle_A, angle_B, angle_C] = angle_calc (side_A,side_B,side_C)

[Aaron]

Now getting the following error:

*Error in angle_calc (line 2)

angle_C = acosd((a^2+b^2-c^2)/(2*a*b)); *

It is set up like the others, as far as I can see.

[Jan]

And what is the error message?

[Aaron]

Error in angle_calc (line 2)

angle_C = acosd((a^2+b^2-c^2)/(2*a*b));

[Image Analyst]

See my answer.

[Walter Roberson]

Does it give an error message such as "inner dimensions must agree" ?

[Image Analyst]

That's what I thought at first (passing in arrays instead of scalars), but it's because a, b, and c are undefined because he used different names for them in the input arguments.

[Jan]

@Aaron: You've posted, where the error occurs, but not the description of the actual problem. But this message would reveal the cause immediately.

[Walter Roberson]

Good catch about the names!

[Image Analyst]

Well because he didn't list the actual error (like Jan noted) I actually had to copy and paste, fix it up a little, and run it to find out the error. This should have been discovered immediately by Aaron, particularly if he knew how to use the debugger (which is always faster than debugging via Answers postings).

[Aaron]

Thank you all for your input. I am fairly new to Matlab so I will do my best to learn how to use the debugger.