If else conditionals in matlab app.designer?

I have a doubt about conditionals on matlab app.designer.

For example in this litlle and simple app. I have defined a private variable F which value is 60.

The point here is that, when I select the "ac" option in the dropmenu below, and click the button, the number 1917 appears on the white box

This is the conditional I have designed to occur that, and doesn't work. The question is that if the option of the dropmenu is only a letter (for instance 'a' or 'b' or whatever, it does work. But when the option is one or more characters, like in the example below, it doesn`t work and appears the following error.

How it is possible that the code above works perfectly when I have only one letter but does not when are two or more characters?

Thank you very much!

Answer 1

[Steven Lord]

Compare:

'ac' == 'ad' % returns a 1-by-2 logical array

ans = 1x2 logical array
   1   0

'ac' == "ad" % returns a 1-by-1 logical array

ans = logical
   0

When you compare two char arrays using ==, the resulting logical array is the same size as the char arrays (or the size of the non-scalar, if one is scalar, or the compatible size if you're using a release that supports implicit expansion and they are compatibly sized.)

When you compare a char array and a scalar string the char array is converted into a string (in my second line of code above, the two character char vector 'ac' becomes the scalar string "ac") and then we compare the string arrays.

If using strings is not an option, use strcmp or one of the functions given in the "See Also" section of the documentation page for the strcmp function.

Answer 2

[Cris LaPierre]

Because your check of the menu value returns a value for each character, not one.

a='ac';
a=='ac'

ans = 1x2 logical array
   1   1

You can use a single &, and your code will run. Better is to use strcmp, though.

strcmp(a,'ac')

ans = logical
   1

Answer 3

[Jan]

if strcmp(app.menu.Value, 'ac') && ...
        

or define the values as string with double quotes, not as "cell string", which is a cell of CHAR vectors.

[NICOLE MIN]

i have the same issue her and how can o define and condition and convert to logical scalar value?

[Jan]

@NICOLE MIN: Without seeing the contents of your variables, there is no chance to guess, what you have to change. Usually an all() or any() helps.

[NICOLE MIN]

Alright! Please take a look tomorrow once I screenshot the variables code tmr. Thanks for your help

[Jan]

Avoid posting screenshots but prefere to post code as text. This makes it muh easier to test and write an answer.

[NICOLE MIN]

properties (Access = private)

Age;

Glucose;

BMI;

sysBP;

diaBP; % Description

Diagnosis

Gender

end

methods (Access = private)

end

% Callbacks that handle component events

methods (Access = private)

% Value changed function: AgeEditField

function AgeEditFieldValueChanged(app, event)

value = app.AgeEditField.Value;

app.Age = value;

end

% Value changed function: GlucoseEditField

function GlucoseEditFieldValueChanged(app, event)

value = app.GlucoseEditField.Value;

app.Glucose = value;

end

% Value changed function: BMIEditField

function BMIEditFieldValueChanged(app, event)

value = app.BMIEditField.Value;

app.BMI = value;

end

% Value changed function: sysBPEditField

function sysBPEditFieldValueChanged(app, event)

value = app.sysBPEditField.Value;

app.sysBP = value;

end

% Value changed function: diaBPEditField

function diaBPEditFieldValueChanged(app, event)

value = app.diaBPEditField.Value;

app.diaBP = value;

end

% Button pushed function: PredictButton

function PredictButtonPushed(app, event)

app.Age = 1:1000;% allow user to field any number in editfield from 1 to 1000

app.Glucose=1:1000;

app.BMI=1:1000;

app.sysBP=1:1000;

app.diaBP=1:1000;

high_glucose =350;

low_glucose=0;

mean_Glucosefeat=121;

input_fuzzy_glucose=175;

high_BMI=60;

low_BMI=0;

mean_BMI=39;

input_fuzzy_BMI=30;

max_rule1=175;

max_use1=350;

max_rule2=30;

max_use2=60;

b =app.Glucose;

c= app.BMI;

d=app.sysBP;

e=app.diaBP;

if app.GenderSwitch.Value=="Male"

(b <=max_rule1 && c<max_rule2 && d<35)&&(e<=117.5 && f<=77);

app.Diagnosis='low risk ';

else

app.GenderSwitch.Value="Male";

(b>=max_rule1 && c==max_rule2&&d>35<50)&&(e>=118 && f<=78);

app.Diagnosis='medium risk ';

end

if app.GenderSwitch.Value=="Male"

(b>=max_rule1 && c>max_rule2&&d>51<60)&&(e>=134 && f<=79);

app.Diagnosis=' risky ';

end

if app.GenderSwitch.Value=="Male"

(b==max_rule1 && b<=max_rule2&&d<35)&&(e<=117.5 && f<=77);

app.Diagnosis='medium risk ';

else

app.GenderSwitch.Value="Male";

(b >=maxrule1 && c>=max_rule2&&d>35<50)&&(e<=117.5 && f<=77);

app.Diagnosis='risky ';

end

if app.GenderSwitch.Value=="Male"

(b >=max_rule1 && c>max_use2&&d>51<60)&&(e<=117.5 && f<=77);

app.Diagnosis='high risk ';

end

if app.GenderSwitch.Value=="Male"

(b==max_rule1 && c<=max_rule2&&d<35)&&(e<=117.5 && f<=77);

app.Diagnosis='risky ';

else

app.GenderSwitch.Value="Male";

(b>=maxrule1 &&c>=max_rule2 && d>35<50)&&(e<=117.5 && f<=77);

app.Diagnosis='risky ';

end

if app.GenderSwitch.Value=="Male"

(b>=max_use1 && c>max_use2 && d>51<60)&&(e<=117.5 && f<=77);

app.Diagnosis='high risk ';

end

if app.GenderSwitch.Value== "Male"

(b==max_rule1 && c<=max_rule2 && d<35)&&(e<=117.5 && f<=77);

app.Diagnosis='risky ';

else

app.GenderSwitch.Value= "Male";

(b >=maxrule1 && c>=max_rule2&& d>35<50)&&(e<=117.5 && f<=77);

app.Diagnosis='risky ';

end

if app.GenderSwitch.Value== "Male"

(b>=max_use1 && c>max_use2&& d>51<60)&&(e<=117.5 && f<=77);

app.Diagnosis='high risk ';

else

app.GenderSwitch.Value= 'Male';

(app.Glucose<=max_rule1 && app.BMI<max_rule2)&&(app.sysBP<=117.5 && app.diaBP<=77);

app.Diagnosis='normal ';

if app.GenderSwitch.Value== "Male"

(app.Glucose >207 && app.Age>60);

app.Diagnosis='danger ';

end

if app.GenderSwitch.Value=="Female"

(b <=max_rule1 && c<max_rule2&& d<35)&&(e<=113 && f<=71);

app.Diagnosis='low risk ';

else

app.GenderSwitch.Value="Female";

(b>=max_rule1 && c==max_rule2 && d>35<50)&&(e>=113 && f<=73);

app.Diagnosis='medium risk ';

end

if app.GenderSwitch.Value== "Female"

(b>=max_rule1 && c>max_rule2 && d<51<60)&&(e>=127 && f<=76);

app.EditField=' risky ';

end

if app.GenderSwitch.Value== "Female"

(b==max_rule1 && c<=max_rule2 && d<35)&&(e<=113 && f<=71);

app.Diagnosis='medium risk ';

else

app.GenderSwitch.Value= "Female";

(app.Glucose >=maxrule1 && app.BMI>=max_rule2 && app.Age>35<50)&&(app.sysBP<=113 && app.diaBP<=73);

app.Diagnosis='risky ';

end

if app.GenderSwitch.Value== "Female"

(b>=max_rule1 && c>max_use2&& d>51<60)&&(e<=127 && f<=76);

app.Diagnosis='high risk ';

end

if app.GenderSwitch.Value== "Female"

(b==max_rule1 && c<=max_rule2 && d<35)&&(e<=113 && f<=71);

app.Diagnosis='risky ';

else

app.GenderSwitch.Value= "Female";

(b>=maxrule1 && c>=max_rule2 && d>35<50)&&(e<=113 && f<=73);

app.Diagnosis='risky ';

end

if app.GenderSwitch.Value== "Female"

(b>=max_use1 && c>max_use2&& d>51<60)&&(e<=127 && f<=76);

app.Diagnosis='high risk ';

else

app.GenderSwitch.Value= "Female";

(b<=max_rule1 && c<max_rule2) &&(d<=113 && e<=71);

app.Diagnosis='normal';

end

if app.GenderSwitch.Value== "Female"

(b>207 && app.Age>60);

app.Diagnosis='danger ' ;

else

app.Glucose=[];

app.BMI=[];

app.sysBP=[];

app.diaBP=[];

app.Age=[];

app.Diagnosis=('Not Applicable');

end

end

% Value changed function: DiagnosisTextArea

function DiagnosisTextAreaValueChanged(app, event)

value = app.DiagnosisTextArea.Value;

app.Diagnosis = value;

end

% Value changed function: GenderSwitch

function GenderSwitchValueChanged(app, event)

value = app.GenderSwitch.Value;

if value=="Female"

app.PregnantCheckBox='on';

app.GenderSwitch.Enable = 'on';

else

end

if value=="Male"

app.Pregnant.CheckBox="off"

% Disable the switches and buttons if they were on

app.GenderSwitch.Enable = 'off';

end

end

% Value changed function: mgdlButton

function mgdlButtonValueChanged(app, event)

value = app.mgdlButton.Value;

value=app.GlucoseEditField.Value*18;

app.Glucose=value;

end

please help ! thanks

[NICOLE MIN]

this is a layout of my app.