switch statement help

 disp('1 for CH4');disp('2 for CO2');disp('3 for N2');
nc =input('components');
if nc > 5
    disp('Too Many component')
    break
end
for i=1:nc
    c(i)=input('c:','s');
    switch c(i)
        case {'c(i)=1'}
            Tc(1,1) = 190;
        case {'c(i)=2'}
            Tc(1,2) = 120;
        case {'c(i)=3'}
            Tc(1,3) = 890;
        case {'c(i)=4'}
            Tc(1,4) = 1210;
        case {'c(i)=5'}
            Tc(1,5) = 1990;
        otherwise
            disp('enter the comp')
    end
end
 % The statement is not working kindly help

[Jan]

Please do not state only, that this "is not working", but describe the occurring problems with any details. It is much easier to solve a problem than to guess, what the problem is.

Answer 1

[Thomas]

try

clear variables
disp('1 for CH4');disp('2 for CO2');disp('3 for N2');
nc =input('components: ');
if nc > 5
    disp('Too Many component')
    break
end

    switch nc
        case 1
            Tc(1,1) = 190
        case 2
            Tc(1,2) = 120
        case 3
            Tc(1,3) = 890
        case 4
            Tc(1,4) = 1210
        case 5
            Tc(1,5) = 1990
        otherwise
            disp('enter the comp')
    end

EDIT This might be what you want:

clear variables
disp('1 for CH4');disp('2 for CO2');disp('3 for N2');
nc =input('components: ');
if nc > 5
    disp('Too Many component')
    break
end

for ii=1:nc
     c{ii}=input('c:','s')
    switch c{ii}
        case '1'
            Tc(1,1) = 190
        case '2'
            Tc(1,2) = 120
        case '3'
            Tc(1,3) = 890
        case '4'
            Tc(1,4) = 1210
        case '5'
            Tc(1,5) = 1990
        otherwise
            disp('enter the comp')
    end
end

[Nasir Qazi]

by input 3 component to nc , I have to assign the 3 components there respective Tc values in order of component selection , yours above edited code only give me one particular value.which I am not looking at

[Walter Roberson]

Then you asked the wrong question.

[Thomas]

Check Edit..

[Nasir Qazi]

exactly Thomas , The one you edit is closer to what I am expecting

Answer 2

[Walter Roberson]

If the user really were entering in the literal string 'c(i)=1' (6 characters) in response to that input() prompt, then those 6 characters would not fit into the c(i) that the input() string is being assigned to. Please keep in mind that a string in MATLAB is an array of characters, not a distinct data type, so multiple array locations need to be allocated to hold a multi-character string.

Expecting the user to know to type in literally

c(i)=4

in response to the "c:" prompt is expecting too much from the user.

[Nasir Qazi]

chk my codes below , is that right?

Answer 3

[Nasir Qazi]

 is that correct 

 clc
clear
disp('1 for CH4');disp('2 for CO2');disp('3 for N2');
nc =input('components');
if nc > 5
    disp('Too Many component')
    break
end
for i=1:nc
    c(i)=input('c:');
    switch c(i)
        case 1
            if c(i)==1;
            Tc(i,:) = 190;
            Pc(i,:) = 2;
            end
        case 2
            if c(i)==2;
            Tc(i,:) = 120;
            Pc(i,:) = 4;
            end
        case 3
            if c(i)==3;
            Tc(i,:) = 890;
            Pc(i,:) = 6;
            end
        case 4
            if c(i)==4;
            Tc(i,:) = 1210;
            Pc(i,:) = 4;
            end
        case 5
            if c(i)==5;
            Tc(i,:) = 1990;
            Pc(i,:) = 8;
            end
        otherwise
            disp('enter the comp')
    end
end

[Walter Roberson]

Probably not. You would not reach case 1 unless c(i)==1 so testing that within the case is redundant.

[Nasir Qazi]

but it runs perfect

[Walter Roberson]

Well if you are happy with it then that is what matters.

[Nasir Qazi]

its not about me happy our not , I want it to run it perfectly that's why I need advice from experts like you .

[Walter Roberson]

You are the one who knows what it needs to do. You already said that it runs perfectly. If it solves your problem then style differences are not important at this point.

If you are asking me whether your code solves your problem, then I cannot answer because you have not clearly expressed what you are trying to do (an example with multiple components would help.) When _I_ look at your code, I see parts of it that look unlikely to be right to _me_, but that could just be because I do not understand what you are trying to do.

[Nasir Qazi]

let me explain , I have multicomponent e.g nc = 7, and I already assign the value of Tc and Pc to all of them , and for example I want to use 4 component from above and only want to use there assign Tc and Pc values and leave the rest , so I need a code for this purpose , Hope you cleared now.

[Walter Roberson]

Which 4 would you want to assign to in that case? The first 4? Would the same value be assigned to Tc for each of the 4? In your array Tc(i,:) which one is the component number, and what does the other dimension represent?

Answer 4

[Andrei Bobrov]

in your case

eg:

c = randi([1 5],10,1);

pt = [[190;120;890;1210;1990],[2;4;6;4;8]];

Tc = pt(c,1);
Pc = pt(c,2);