why can't my 2nd output argument in my function return any value?

Hi, I 'm trying to create a function that calculates the root from the the quadratic eqn. i need to display the two roots separately but why does my second root, k not appear from the output.argument. thanks i am new to matlab

Answer 1

[Star Strider]

You have to ask it specifically for as many outputs as you want it to return. By default, if you only ask it for one, it will only return the first. This call returns all of them:

a = 2;
b = 5;
c = 10;
[j,k,group]=quadratic_roots(a,b,c)

Also, I would change:

group='non-equal complex valued roots'

to:

group='complex-conjugate roots'

[Natalia Wong]

wht does 2 5 and 10 mean? so how do i correct my code?

[Natalia Wong]

i did what you said but i didnt get the answer i wanted if i input(2,-4,1) i should get 1.71 and 0.2929 as ans. I'm required to use non equal complex roots as group Thanks

[Natalia Wong]

i want j to be the first root and k to be the second root. How to make them appear separately liek j = 1.71 and k = 0.2929

[Star Strider]

Your code works for me. If I use:

a =  2;
b = -4;
c =  1;
[j,k,group]=quadratic_roots(a,b,c)

I get:

group =
non-equal real valued roots

j =
      0.29289

k =
       1.7071

group =
non-equal real valued roots

You need to put semicolons at the end of your ‘group’ lines to suppress the output:

group='non-equal real valued roots';

and so for the others.

[Natalia Wong]

if i dont sppress j and k i can get the answer but then the answer in the output argument gives me 0.2929 only it appears like this j = 0.2929 k = 1.7071 group = non equal real valued roots ans = 0.2929

[Star Strider]

How are you calling your function? It works correctly when I run it.

[Natalia Wong]

quadratic_roots(2,-4,1)

[Star Strider]

That will only return the first output and will assign it to the default variable, ‘ans’.

Call it like this instead:

[j,k,group]=quadratic_roots(a,b,c)

or with your particular arguments:

[j,k,group]=quadratic_roots(2,-4,1)

[Natalia Wong]

Thank you so much Star Strider. Since you're so good can you help me with this task? I'm supposed to create a program that prompts the user to guess the colour (5 characters) and tell them how many colours and position that that they guessed are correct and that how many colours only that they guessed are correct. Pls help I'm stuck. If result == hidden_seq gives me 1 0 0 0 0 means that the first colour and first position is correct but how do I tell that to the user since the hidden sequence varies and the user enters a different different seq of colours everytime?

%Written by:
% Student ID:
%ver 01, 8 Dec by JL

clc
clear

% Initiate Random Color Sequence
% r-red; b-blue; y-yellow; g-green; w-white; p-purple; o-orange;
all_colors = 'rbygwpo';
index = randperm(7);
hidden_seq = all_colors(index(1:5));

   count = 0;

while 1
    %Prompting user to enter input
    result = input('Guess the 5 characters colour sequence: ');
    count = count + 1;

      %Validate user input
      if numel(result) > 5 || numel(result) < 5
          error('You have entered more or less than 5 characters')
      end

      %Check the user guesses
     result == hidden_seq 

end

[Walter Roberson]

That is already being dealt with in your question http://uk.mathworks.com/matlabcentral/answers/258976-i-m-having-problems-creating-a-program-that-prompts-a-user-to-guess-the-colour

[Star Strider]

@Natalia — If my Answer solved your problem, please Accept it.

@Walter — Thank you.