Nested elseif statement syntax

Hi,

I've been working on a logic tree to work through repeating numbers as inputs where the outputs are alphabetical, similar to the Multi-tap texting pre-smartphone. (i.e. '2'=a, '2' '2' =b, '3' = d, '3' '3' '3' = f, and so on.

I tried using nested elseifs that seemed to work on their own, but paired with the rest of the elseif statements only the sequence for inputs of '9' (wxyz) is working. Does Anyone know what my error is here? I know this code is inefficient but I did my best for what is my first matlab project.

if inputs(1) == 0
disp('error, no input')
elseif inputs(1) == 9
if inputs(2) == 0
disp('w')
elseif inputs(2) == 9
if inputs(3) == 0
disp('x')
elseif inputs(3) == 9
if inputs(4) == 0
    disp('y')
elseif inputs(4) == 9
    disp('z')
elseif inputs(1) == 8
if inputs(2) == 0
disp('t')
elseif inputs(2) == 8
if inputs(3) == 0
disp('u')
elseif inputs(3) == 8
disp('v')
elseif inputs(1) == 7
if inputs(2) == 0
disp('p')
elseif inputs(2) == 7
if inputs(3) == 0
disp('q')
elseif inputs(3) == 7
if inputs(4) == 0
    disp('r')
elseif inputs(4) == 7
    disp('s')
elseif inputs(1) == 6
if inputs(2) == 0
disp('m')
elseif inputs(2) == 6
if inputs(3) == 0
disp('n')
elseif inputs(3) == 6
disp('o')
elseif inputs(1) == 5
if inputs(2) == 0
disp('j')
elseif inputs(2) == 5
if inputs(3) == 0
disp('k')
elseif inputs(3) == 5
disp('l')
elseif inputs(1) == 4
if inputs(2) == 0
disp('g')
elseif inputs(2) == 4
if inputs(3) == 0
disp('h')
elseif inputs(3) == 3
    disp('i')
  elseif inputs(1) == 3
    if inputs(2) == 0
        disp('d')
    elseif inputs(2) == 3
        if inputs(3) == 0
            disp('e')
        elseif inputs(3) == 3
            disp('f')
           elseif inputs(1) == 2
if inputs(2) == 0
        disp('a')
elseif inputs(2) == 2
if inputs(3) == 0
    disp('b')
elseif inputs(3) == 2
    disp ('c')
else 
    disp('error, incorrect input')
end
end
        end
    end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end

[Image Analyst]

I don't understand. What did you type in (what is inputs)? Are you typing in a sequence of numbers and have to somehow translate those numbers into characters of the a-z alphabet? Give an example of inputs and what your output would be.

[per isakson]

Indentation makes it easier to read the code

if inputs(1) == 0
    disp('error, no input')
elseif inputs(1) == 9
    if inputs(2) == 0
        disp('w')
    elseif inputs(2) == 9
        if inputs(3) == 0
            disp('x')
        elseif inputs(3) == 9
            if inputs(4) == 0
                disp('y')
            elseif inputs(4) == 9
                disp('z')
            elseif inputs(1) == 8
                if inputs(2) == 0
                    disp('t')
                elseif inputs(2) == 8
                    if inputs(3) == 0
                        disp('u')
                    elseif inputs(3) == 8
                        disp('v')
                    elseif inputs(1) == 7
                        if inputs(2) == 0
                            disp('p')
                        elseif inputs(2) == 7
                            if inputs(3) == 0
                                disp('q')
                            elseif inputs(3) == 7
                                if inputs(4) == 0
                                    disp('r')
                                elseif inputs(4) == 7
                                    disp('s')
                                elseif inputs(1) == 6
                                    if inputs(2) == 0
                                        disp('m')
                                    elseif inputs(2) == 6
                                        if inputs(3) == 0
                                            disp('n')
                                        elseif inputs(3) == 6
                                            disp('o')
                                        elseif inputs(1) == 5
                                            if inputs(2) == 0
                                                disp('j')
                                            elseif inputs(2) == 5
                                                if inputs(3) == 0
                                                    disp('k')
                                                elseif inputs(3) == 5
                                                    disp('l')
                                                elseif inputs(1) == 4
                                                    if inputs(2) == 0
                                                        disp('g')
                                                    elseif inputs(2) == 4
                                                        if inputs(3) == 0
                                                            disp('h')
                                                        elseif inputs(3) == 3
                                                            disp('i')
                                                        elseif inputs(1) == 3
                                                            if inputs(2) == 0
                                                                disp('d')
                                                            elseif inputs(2) == 3
                                                                if inputs(3) == 0
                                                                    disp('e')
                                                                elseif inputs(3) == 3
                                                                    disp('f')
                                                                elseif inputs(1) == 2
                                                                    if inputs(2) == 0
                                                                        disp('a')
                                                                    elseif inputs(2) == 2
                                                                        if inputs(3) == 0
                                                                            disp('b')
                                                                        elseif inputs(3) == 2
                                                                            disp ('c')
                                                                        else
                                                                            disp('error, incorrect input')
                                                                        end
                                                                    end
                                                                end
                                                            end
                                                        end
                                                    end
                                                end
                                            end
                                        end
                                    end
                                end
                            end
                        end
                    end
                end
            end
        end
    end
end

[Benjamin Weir]

My inputs is a matrix determined by another program that will only return the first number it sees, followed by either the number repeating or a '0', and it is always inputs = [x x x x]. So for example, if the first number is '3', the program will always return inputs = [3 3 0 0], which should be a return of 'e'.

I have it set so that for even inputs = [3 3 3 3] would be the same as inputs = [3 3 3 0], because on a nokia esque phone there is no fourth character to cycle to, only 'd', 'e', and 'f', so both of these cases would be 'f'.

Therefore, i am just confused on how to get this code to work because it is pretty much ok for what i need.

Answer 1

[per isakson]

There is no else block in the outer if-elseif-else-end. This code will display something only for inputs(1)==0 and for inputs(1)==9. Thus, "only the sequence for inputs of '9' (wxyz) is working."

if inputs(1) == 0
    disp('error, no input')
elseif inputs(1) == 9
    % a lot of nested if...end blocks 
end

[Benjamin Weir]

Thank you! Are you saying that I should remove the else block? When i do that it doesnt fix the issue of not returning results for, say inputs = [3 3 0 0], which should be 'e'

else disp('error, incorrect input')

[per isakson]

No, I just try to explain why your script doesn't work, e.g. return "e" for [3 3 0 0].

Read carefully the documentation on if, elseif, else - Execute statements if condition is true.

Your script is logically flawed, there is no way it can return a letter for any "key" other than "9". The statement, elseif inputs(1) == 8, etc., must appear in the outer/top if-elseif-else-end block.

Below, I started on a new code. Currently, it only works for the key, "2".

%%
MultiTapTexting_( [2,0,0,0] )

ans = 'a'

MultiTapTexting_( [2,2,0,0] )

ans = 'b'

MultiTapTexting_( [2,2,2,0] )

ans = 'c'

MultiTapTexting_( [2,2,2,2] )

ans = 'c'

% MultiTapTexting_( [2,0,2,0] )
MultiTapTexting_( [2,2,2.2,0] )

Error using solution>MultiTapTexting_ (line 13)
incorrect input

%%
function    out = MultiTapTexting_( inputs )
    
    % Assert that the input value is legal
    assert( ismember( inputs(1), (2:9) )            , 'incorrect input' )
    assert( all(ismember( inputs(2:4), [0,(2:9)] ) ), 'incorrect input' )
    assert( inputs(2)==0 || inputs(2)==inputs(1)    , 'incorrect input' )
    assert( inputs(3)==0 || inputs(3)==inputs(2)    , 'incorrect input' )
    assert( inputs(4)==0 || inputs(4)==inputs(3)    , 'incorrect input' )
    
    % The input value is legal, thus no more error checking needed  
    if inputs(1) == 2
        if inputs(2) == 0
            out = 'a';
        else
            if inputs(3) == 0
                out = 'b';
            else
                out = 'c';
            end
        end
    elseif inputs(1) == 3
    elseif inputs(1) == 4
    elseif inputs(1) == 5
    elseif inputs(1) == 6
    elseif inputs(1) == 7
    elseif inputs(1) == 8
    elseif inputs(1) == 9
    end
end

Answer 2

[Walter Roberson]

keymap = {
    {'1' 'punctuation'},
    {'2', 'a', 'b', 'c'},
    {'3', 'd', 'e', 'f'},
    {'4', 'g', 'h', 'i'},
    {'5', 'j', 'k', 'l'},
    {'6', 'm', 'n', 'o'},
    {'7', 'p', 'q', 'r', 's'},
    {'8', 't', 'u', 'v'},
    {'9', 'w', 'x', 'y', 'z'},
    {'*', 'more punctuation'},
    {'0'},
    {'shift', '#'}
    }

... Taken directly from an old Nokia phone on my shelf.

You start in the "beginning of letter" state. You get an input character. You take note of the character

Label "A": check: is the length of the cell associated with that character 1? If it is, emit the character and return to "beginning of letter" state.

If the length associated with the cell is not 1, then set a count to 1 and set the "current key" to the input, and set the "current character" to the first entry in the cell. Then enter "inside letter" state.

Label "Inside letter" state:

Try to get the next input. If end of input, then emit the "current character" and reset to "beginning of letter" state, and end

If the input key is different from the "current key", then emit the current character, and go back to "A"

If the input key is the same as the "current key" then set the count to (count mod length(cell associated with current key) + 1), and set the "current key" to the cell associated with "current key" indexed by the count. And go back to "inside letter" state

I don't know if my batteries on my old Nokia are completely dead or if I can fire it up long enough to determine the punctuation lists. I will leave it plugged into power for a bit.

[Walter Roberson]

%Nokia 5130c key map
keymap = {
    {'.', ',', '''', '?', '!', '"', '1', '-', '(', ')', '@', '/', ':', '_'},
    {'a', 'b', 'c', '2'},
    {'d', 'e', 'f', '3'},
    {'g', 'h', 'i', '4'},
    {'j', 'k', 'l', '5'},
    {'m', 'n', 'o', '6'},
    {'p', 'q', 'r', 's', '7'},
    {'t', 'u', 'v', '8'},
    {'w', 'x', 'y', 'z', '9'},
    {' ', '0', char(13) },  %char(13) is carriage return
    }

The * character does not input characters in itself. On the first press it opens a list of punctuation characters, but you have to cursor to one of them and press OK . On the second press it opens a list of emoji, but again you have to cursor to one of them and press OK.

The # character does not input characters in itself. It cycles between shift mode. When you are at the beginning of the line, the default mode is upper-case first character and lower case remaining characters until the end of sentance. If you are at the beginning of a sentance, then the first # activates all-caps mode and the second # activates all-lowercase mode, and the third # goes back to upper-first mode. If you are not at the beginning of the sentance but are at the beginning of a word then (by default) you are in all-lower mode, and the first # activates upper-first mode and the second activates all-caps and the third activates all-lower (and cycle). If you are not at the beginning of a sentance or the beginning of a word, then the first # activates all caps-mode and the second activates all-lower mode, and cycle back to all-caps (in this situation, upper-first is not offered.)

[Benjamin Weir]

Hi Walter,

I am using inputs = [x x x x] from a program that is converting the DTMF tones into their numerical input. So my program has inputs = [3 3 0 0], this should be 'e' based on the Nokia-style system. This will only be working in a combination of the same numerical input and '0', so I am not working with anything other than 0-9. My follow-up question is, using the keymap you provided, how can my inputs matrix be applied? if i begin with the matrix already set, how can I have the inputs choose a character from the list?