Undefined function 'times' for input arguments of type 'cell'.

Question

Benjamin 2012-12-17

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/56751-undefined-function-times-for-input-arguments-of-type-cell

I am trying to write a function that will determine the heat needed to change the temperature of water between two given temperatures and I keep getting this error. Anybody know how to fix it?

c_ice = 2060;
c_water = 4180;
c_steam = 2020;
Hf = 332000;
Hv = 2260000;
% Input
mass = inputdlg('What is the mass of the H2O?','Mass of H20');
statei = listdlg('PromptString', 'What is the initial state of the H2O?',...
    'SelectionMode','Single',...
    'ListString',{'Ice','Liquid','Gas'},... 
    'Name', 'Initial State',...
    'ListSize',[230 100]);
statef = listdlg('PromptString', 'What is the final state of the H2O?',...
    'SelectionMode','Single',...
    'ListString',{'Ice','Liquid','Gas'},... 
    'Name', 'Final State',...
    'ListSize',[230 100]);
switch statei
    case 1
        tempi = inputdlg('What is the initial temperature of the H2O between -273-0ºC',...
            'Initial Temperature');
    case 2
        tempi = inputdlg('What is the initial temperature of the H2O between 0-100ºC',...
            'Initial Temperature');
    case 3
        tempi = inputdlg('What is the initial temperature of the H2O between 100-300ºC',...
            'Initial Temperature');
end
tempi = str2double(tempi);
switch statef    
    case 1
        tempf = inputdlg('What is the final temperature of the H2O between -273-0ºC',...
            'Final Temperature');
    case 2
        tempf = inputdlg('What is the final temperature of the H2O between 0-100ºC',...
            'Final Temperature');
    case 3
        tempf = inputdlg('What is the final temperature of the H2O between 100-300ºC',...
            'Final Temperature');
end
tempf = str2double(tempf);        
% Process
if tempi < 0
    if tempf < 0
        heat = mass*c_ice*(tempf - tempi);
    elseif  tempf < 100
        heat = mass*c_ice*(tempi) + mass*Hf + mass*c_water*(tempf);
    else tempf > 100
        heat = mass*c_ice*(tempi) + mass*Hf + mass*c_water*(100) + mass*Hv + mass*c_steam*(tempf - 100);
    end
elseif tempi > 0 && tempi < 100
    if tempf < 0
        heat = mass*c_water*(-tempi) + mass*Hf + mass*c_ice*(-tempf);
    elseif  tempf < 100
        heat = mass*c_water*(tempf - tempi);
    else tempf > 100
        heat = mass*c_water*(100 - tempi) + mass*Hv + mass*c_steam*(tempf - 100);
    end
else
    if tempf < 0
        heat = mass*c_steam*(tempi - 100) + mass*Hv + mass*c_water*(100) + mass*Hf + mass*c_ice*(-tempf);
    elseif  tempf < 100
        heat = mass*c_steam*(tempi - 100) + mass*Hv + mass*c_water*(tempf - 100);
    else tempf > 100
        heat = mass*c_ice*(tempf - tempi);
    end
endc_ice = 2060;
c_water = 4180;
c_steam = 2020;
Hf = 332000;
Hv = 2260000;
% Input
mass = inputdlg('What is the mass of the H2O?','Mass of H20');
statei = listdlg('PromptString', 'What is the initial state of the H2O?',...
    'SelectionMode','Single',...
    'ListString',{'Ice','Liquid','Gas'},... 
    'Name', 'Initial State',...
    'ListSize',[230 100]);
statef = listdlg('PromptString', 'What is the final state of the H2O?',...
    'SelectionMode','Single',...
    'ListString',{'Ice','Liquid','Gas'},... 
    'Name', 'Final State',...
    'ListSize',[230 100]);
switch statei
    case 1
        tempi = inputdlg('What is the initial temperature of the H2O between -273-0ºC',...
            'Initial Temperature');
    case 2
        tempi = inputdlg('What is the initial temperature of the H2O between 0-100ºC',...
            'Initial Temperature');
    case 3
        tempi = inputdlg('What is the initial temperature of the H2O between 100-300ºC',...
            'Initial Temperature');
end
tempi = str2double(tempi);
switch statef    
    case 1
        tempf = inputdlg('What is the final temperature of the H2O between -273-0ºC',...
            'Final Temperature');
    case 2
        tempf = inputdlg('What is the final temperature of the H2O between 0-100ºC',...
            'Final Temperature');
    case 3
        tempf = inputdlg('What is the final temperature of the H2O between 100-300ºC',...
            'Final Temperature');
end
tempf = str2double(tempf);        
% Process
if tempi < 0
    if tempf < 0
        heat = mass*c_ice*(tempf - tempi);
    elseif  tempf < 100
        heat = mass*c_ice*(tempi) + mass*Hf + mass*c_water*(tempf);
    else tempf > 100
        heat = mass*c_ice*(tempi) + mass*Hf + mass*c_water*(100) + mass*Hv + mass*c_steam*(tempf - 100);
    end
elseif tempi > 0 && tempi < 100
    if tempf < 0
        heat = mass*c_water*(-tempi) + mass*Hf + mass*c_ice*(-tempf);
    elseif  tempf < 100
        heat = mass*c_water*(tempf - tempi);
    else tempf > 100
        heat = mass*c_water*(100 - tempi) + mass*Hv + mass*c_steam*(tempf - 100);
    end
else
    if tempf < 0
        heat = mass*c_steam*(tempi - 100) + mass*Hv + mass*c_water*(100) + mass*Hf + mass*c_ice*(-tempf);
    elseif  tempf < 100
        heat = mass*c_steam*(tempi - 100) + mass*Hv + mass*c_water*(tempf - 100);
    else tempf > 100
        heat = mass*c_ice*(tempf - tempi);
    end
end

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Answer 1

Teja Muppirala 2012-12-17

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/56751-undefined-function-times-for-input-arguments-of-type-cell#answer_68690

在 MATLAB Online 中打开

When you use INPUTDLG to get input from the user, the result is stored as a string (text) in what is known as a cell array. It is not a numeric datatype, but rather a datatype that is often used to store mixed numbers/text, so you can't do numeric operations with it. You need to convert from a cell array/text to a plain old numeric array. You can use STR2DOUBLE to do this.

For example, you wrote this:

mass = inputdlg('What is the mass of the H2O?','Mass of H20')

Now "mass" is a cell array. To use it for further calculations, change it to a double:

mass = str2double(mass)

Now you can do things like